Principal developer of From Finches to Fishes
Betty Brown, MS
Additional contributors to From Finches to Fishes
Lisa Pierce, MEd, Head of Revision TeamJames “Maxx” Andersen, BFA
Walter E. “Skip” Bollenbacher, PhD
Lenis Chen, MEd
Dana Haine, MS
Jennifer Shelton Murphy, MA
Christine Muth, PhD
Grant Parkins, MS
Benjamin Rogers, BS
Joy M. Salyers, MA
Amber Vogel, PhD
Jane Wright, MEd
John Zhu, BA

DESTINY developed From Finches to Fishes through the Partnership for Minority Advancementin the Biomolecular Sciences based at UNC-Chapel Hill, with support from the Howard Hughes Medical
Institute.
DESTINY (http://www.destiny.unc.edu) is the University of North Carolina at Chapel Hill’s Traveling
Science Learning Program. DESTINY is a multi-faceted pre-college education initiative that seeks toempower teachers, schools, and communities to transform science learning environments. DESTINY
has been supported in part by the State of North Carolina; grants from GlaxoSmithKline, the Howard
Hughes Medical Institute, and the National Aeronautics and Space Administration; and a Science Education
Partnership Award from the National Center for Research Resources, part of the National Institutes of Health.
Additional support has come from Bio-Rad, IBM, Medtronic, and New England BioLabs.

© 2006 DESTINY. DESTINY grants teachers permission to reproduce curriculum materials from this notebook and to use materials provided on the accompanying CD-ROM for classroom use only, without alteration, provided all copies and materials containthe following statement: “© 2006 DESTINY. This work is reproduced with the permission of DESTINY, UNC-Chapel Hill’s
Traveling Science Learning Program. No other use is permitted without the express prior written permission of DESTINY. For
permission, contact DESTINY, UNC-Chapel Hill’s Traveling Science Learning Program, CB# 3280, Coker Hall, UNC-Chapel Hill,
Chapel Hill, NC 27599-3280.”© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

1This From Finches to Fishes module uses:

Bio-Rad Comparative Proteomics Kit I: Protein Profiler Module
Catalog # 1662700EDU
explorer.bio-rad.com
1-800-4BIORAD (1-800-424-6723)

2© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

TABLE OF CONTENTS
KEY TERMS ..........................................................5
ALIGNMENTS ......................................................7
The Key Components of the 5E Model ...................7
North Carolina Standard Course of Study ...............8
National Science Education Standards .................. 11
INTRODUCTION................................................13
Darwin’s Theories of Evolution .............................13
Speciation...............................................................14
Evidence for Evolution ..........................................16
DNA and Divergence .............................................16
Pre-lab ....................................................................16
Wet-lab ...................................................................17
Post-lab/Additional Activities ................................18
Background ............................................................19
Connection to Other DESTINY Modules ..............23
PRE-LAB ..............................................................25
Utilizing the 5E Instructional Model .....................26
Engagement Activity:
The Trip — Prepare for Departure
Instructions for Teachers ........................................27
Prepare for Departure Travel Packet ......................29
Group Report Sheet................................................34
Narrative for PowerPointTM Presentation:
Imaginary Trip to the Galapagos............................35
Possible Questions that May Arise
from Group Report Sheet:
Imaginary Trip to the Galapagos............................37
KEY Possible Questions that May Arise
from Group Report Sheet:
Imaginary Trip to the Galapagos............................38
Exploration Activity: Go Fish
Instructions for Teachers ........................................40
Tally Sheet — Go Fish ...........................................41
Exploration Activity: Go Fish
Instructions for Students ........................................42
KEY Exploration Activity: Go Fish........................43
Explanation Activity ..............................................44
Elaboration Activity ...............................................44
Discussion Questions for Elaboration....................46
KEY Discussion Questions for Elaboration ...........47
Figure 1: Peppered Moths —A Case of Rapid Natural Selection ........................49
Figure 2: Speciation ...............................................50
Figure 3: Evolution among Galapagos Finches .....51
Figure 4: Descended or Related? ...........................52
Figure 5: Primate Evolution ...................................69
Evaluation Activity ................................................70
KEY Evaluation Activity ........................................72

WET-LAB .............................................................73
Wet-lab Engagement: A Fishy Family Tree
Instructions for Teachers ........................................74
A Fishy Family Tree...............................................75
Figure 6: Fish With Scales .....................................76
KEY A Fishy Family Tree ......................................77
Figure 7: Fish Evolutionary Tree ...........................78
Background for the Wet-lab ...................................79
Engagement............................................................80
Exploration.............................................................81
Explanation ............................................................81
Evaluation ..............................................................81
Protein Cards..........................................................83
Wet-lab: Fish Protein Fingerprinting
by Gel Electrophoresis ...........................................89
Laboratory Day 1: Sample Preparation —Muscle Protein Extraction......................................90
Laboratory Day 2: Electrophoresis ........................91
Data/Observation Sheet .........................................94
KEY Data/Observation Sheet .................................95
Protein Profiler Module — Quick Guide ...............96
List of Equipment Needed .....................................97
POST-LAB ............................................................99
Analyzing Results of Gel Electrophoresis andDetermining Significance of Data ........................100
Protein Fingerprinting: Analyzing
Results of Gel Electrophoresis .............................101
What Do the Bands Reveal? ................................102
What Is the Significance of Your Data? ...............102
Interpreting the Bands Collectively:
Qualitative Comparisons of Protein Profiles........103
Analysis and Interpretation of Results:
Detailed Gel Analysis ..........................................104
Quiz Game Questions .......................................... 112
KEY Quiz Game Answers .................................... 113
Discussion Questions:
Isn’t Evolution Just a Theory? ............................. 114
ADDITIONAL ACTIVITIES ........................... 115
Rubric for Scoring the Evolutionary Essay ......... 116
Using Databases to Obtain Real Amino Acid
Sequence Data to Create Cladograms .................. 117
KEY Using Databases to Obtain Real Amino
Acid Sequence Data to Create Cladograms .........121
BLAST-Searching Questions ...............................123
KEY Answers to BLAST-Searching Questions ....124
INTERDISCIPLINARY BRIDGES .................125
Picture This: A Writing and Listening Exercise
for Science and Non-Science Classrooms ...........126
Picture This: Evolution worksheet .......................128
Darwin, the Writer ...............................................129
Discussion Questions, Guided Reading,and Activities for Charle Darwin’s
On the Origin of Species ......................................131© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

3

4© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

KEY TERMS

Dalton (Da) — a unit of molecular weight equal to themass of a hydrogen atom, 1.66 x 10-24 gm; also calledatomic mass unit.

Abiotic — the non-living part of the environment, suchas air, water, and soil.

Denature — to disrupt or break apart a protein’s threedimensional or tertiary structure, usually with heat,alkali, or acid.

Actin — contractile protein found in muscle tissue,
organized into thin filaments.
Adaptive radiation — relatively rapid evolution ofmany species from a single ancestor; generally occurs inenvironments where there are various unoccupied niches.
Allele — any of the alternate forms of nucleotide
sequences forming genes that determine inherited traits.
Organisms receive one allele from each parent; an organism inheriting two identical alleles is homozygous, and anorganism inheriting two different alleles is heterozygous.
Analogous — structures that serve identical functions
and look somewhat alike, but have different origins. An
example would be the wings of a bird and the wings ofan insect.
Anode — the positive electrode in an electrophoresis
chamber toward which negatively charged particles are
attracted.
BME — β-mercaptoethanol — reducing agent that may
be added to an ionic detergent and heat to ensure complete breakage of disulfide bonds in a protein structure.
Biogeography — scientific study that uses geography
to describe the distribution of plant and animal species,
and is used to explain how unrelated species in different
regions of the world look alike when found in similar
environments.
Biotic — all the living organisms in the environment.
Charge density — ratio of charge to mass of a protein.
Cladogram — a dichotomous phylogenetic tree thatbranches repeatedly, suggesting a classification oforganisms based on the time sequence in which evolutionary branches arise.

Disulfide bridges (bond) — the S-S bond between
amino acids in a polypeptide chain which contributes tothe tertiary and quaternary structure of proteins.
Divergent evolution — also known as adaptive radiation, by which organisms with a common ancestor thatappear different externally but are similar internally.
Embryology — the scientific study which reveals
similar stages in development (ontogeny) among related
species. The similarities help establish evolutionary
relationships (phylogeny). Early embryos of manydifferent vertebrate species look remarkably similar.
Evolution — the process that has transformed life forms
on Earth. One species can arise into another species
through the gradual genetic changes over generations
brought on by environmental influences or the more rapid change brought on by sudden environmental changes
known as punctuated equilibrium. Evolution is supported
by fossil record evidence, comparative anatomy andembryology, Gregor Mendel’s research in genetics, andCharles Darwin’s theory of natural selection.
Evolutionary biology — the scientific study which
compares different living organisms to one anotherand to fossil forms to get an understanding of how
individual species arose from earlier forms and themechanisms that gave rise to the changes involved.
Exon — the region of a gene that is translated intoamino acids.
Fingerprint — distinct pattern of bands on a protein
gel formed during gel electrophoresis; useful as an
identifying characteristic of a sample or species.

Codon — a set of three nucleotides (DNA bases) thatcode for an amino acid.

Gel electrophoresis — a technique used to separate
molecules that carry electrical charges. The molecules
separate from each other according to the different rates
at which they migrate through an electrical field set up
in a gel soaked in a chemical solution.

Comparative anatomy — scientific study that compares and describes two kinds of structures which maylead to the identification of evolutionary relationships
among species.

Gene — the basic unit of heredity found on a specificregion of DNA, occupying a specific place on a chromosome, that encodes information for the synthesis of asingle polypeptide.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

5Genetic drift — fluctuations in the frequency of a genein a small isolated population that occurs strictly byrandom chance rather than natural selection.
Genome — the entire complement of genes in an
organism.
Genomics — the study of all the nucleotide sequencesin the chromosomes of an organism.
Habitat — the area in the environment where anorganism lives.
Homologous — structures or similar features thatoriginated in a shared ancestor. For example, theforelimbs of the penguin, alligator, bat, and human allderived from the same embryological structures.
Intron — region of a gene that is not translated intoamino acids (compare to exon).

Phylogeny — the evolutionary development of species
based on lineage and history of descent.
Posttranscriptional modification — alterations thatallow one gene to code for many proteins.
Posttranslational modification — alterations ofproteins after they are synthesized by the cell.
Protein — one of the complex organic chemicalcompounds that form the basis of living tissues; consistof long chains of amino acids connected by peptide
bonds to form one or more polypeptides. Examples are
enzymes, hemoglobin, and antibodies.
Protein folding — the process by which a protein
bends and twists to achieve its normal three-dimensional shape.

Kilodalton (kD) — 1,000 daltons.

Proteome (protein complement expressed by agenome) — the complete protein profile found under
given conditions in a biological sample.

Molecular biology — the scientific study of nucleotide
and amino acid sequences of DNA and proteins from different species.

Proteomics — the study of the proteome in specificcells, tissues, organs, organ systems, or organisms during a specific time period (e.g., during development).

Morphology — form or structure of an organism.

SDS — sodium dodecyl sulfate, a strongly anionicdetergent used to help denature a protein.

mRNA — messenger ribonucleic acid that carries themessage transcribed from DNA in the cell nucleus to
the ribosomes found in the cytoplasm with information
to carry out protein synthesis.
Myosin — a protein found in muscle tissue that isorganized into thick filaments made up of an aggregateof similar proteins.
Native — the natural structure of a protein found within
the organism.
Niche — the role of an organism in its environment;
how an organism uses all the biotic and abiotic factorsof its habitat.
Ontogeny — the development of an organism from thefertilized egg to maturity.
PAGE — polyacrylamide gel electrophoresis used in
the laboratory analysis of protein and DNA structures.
Paleontology — the scientific study of life in thegeologic past, including the study of fossils to determine the prehistoric existence of extinct species,changes in species, and the formation of new species.

6

SDS-PAGE — sodium dodecyl sulfate — polyacrylamide gel electrophoresis, a form of electrophoresis thattreats samples with SDS to denature proteins.
Species — organisms that have the ability to interbreed
and produce fertile offspring.
Speciation — the formation of a new species which
may occur as a result of isolation from a geographicalbarrier, or other kind of barriers, that prevents interbreeding between the two resulting populations.
Transcription — the process in a cell in which genetic
information from DNA is copied to a complementarystrand of RNA, specifically messenger RNA.
Translation — the process in the ribosomes in whicha strand of messenger RNA directs the assembly of aprotein from amino acids.
tRNA — transfer RNA delivers the amino acids necessary for protein synthesis to the ribosomes.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

The Key Components of the 5E Model
WHAT THE TEACHER DOES THAT IS

PHASEENGAGEEXPLOREEXPLAIN. ...
...
... ...
....
..... ....
..........
....
. ....
..
..... ...
... ...
....

. .... ..

ELABORATEEVALUATE

Consistent with the 5E Model

Inconsistent with the 5E Model• Creates interest• Generates curiosity• Raises questions• Elicits responses that uncover what students knowor think about the concept/subject• Explains concepts• Provides definitions and answers• States conclusions• Provides premature answers to students’ questions• Lectures• Encourages students to work together without direct
instruction from teacher• Observes and listens to students as they interact• Asks probing questions to redirect students’ investigations when necessary• Provides time for students to puzzle through problems• Acts as a consultant for students• Provides answers• Tells or explains how to work through the problem• Tells students they are wrong• Gives information or facts that solve the problem• Leads students step-by-step to a solution• Encourages students to explain concepts and definitions in their own words• Asks for justification (evidence) and clarificationfrom students• Formally provides definitions, explanations, andnew labels• Uses students’ previous experiences as the basis for
explaining concepts• Accepts explanations that have no justification• Neglects to solicit students’ explanations• Introduces unrelated concepts or skills• Expects students to use formal labels, definitions,and explanations provided previously• Encourages students to apply or extend concepts
and skills in new situations• Reminds students of alternative explanations• Refers students to existing data and evidence and asks
“What do you already know?”“Why do you think…?”• Provides definitive answers• Tells students they are wrong• Lectures• Leads students step-by-step to a solution• Explains how to work through the problem• Observes students as they apply new concepts andskills• Assesses students’ knowledge and/or skills• Looks for evidence that students have changed theirthinking or behaviors• Allows students to assess their own learning andgroup process skills• Asks open-ended questions, such as “Why do you
think?”“What evidence do you have?”“What do you
know about x?”“How would you explain x?”• Tests vocabulary words, terms, and isolated facts• Introduces new ideas or concepts• Creates ambiguity• Promotes open-ended discussion unrelated toconcept or skill(Trowbridge & Bybee, 1990), adapted by Biological Sciences Curriculum Study
Available online at http://science.education.nih.gov/supplements/nih1/diseases/guide/module3.htm© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

72005-06 North Carolina Standard Course of Study for Biology — Grades 9-12*** Highlighted sections are objectives addressed in the From Finches to Fishes module
Strands: Nature of Science, Science as Inquiry, Science and Technology, Science in Personal andSocial Perspectives. The strands provide the context for teaching of the content Goals and Objectives.
Competency Goal 1:
The learner will develop abilities necessary to do and understand scientific inquiry.
Objectives
1.01 Identify biological questions and problems that can be answered through scientific investigations.
1.02 Design and conduct scientific investigations to answer biological questions.
• Create testable hypotheses• Identify variables• Use a control or comparison group when appropriate• Select and use appropriate measurement tools• Collect and record data
• Organize data into charts and graphs• Analyze and interpret data
• Communicate findings
1.03 Formulate and revise scientific explanations and models of biological phenomena using logic and evidence to:• Explain observations• Make inferences and predictions• Explain the relationship between evidence and explanation
1.04 Apply safety procedures in the laboratory and in field studies:• Recognize and avoid potential hazards•Safely manipulate materials and equipment needed for scientific investigations
1.05 Analyze reports of scientific investigations from an informed, scientifically literate viewpoint including
considerations of:• Appropriate sample• Adequacy of experimental controls• Replication of findings•Alternative interpretations of the data
Competency Goal 2:
The learner will develop an understanding of the physical, chemical and cellular basis of life.
Objectives
2.01 Compare and contrast the structure and functions of the following organic molecules:• Carbohydrates• Proteins• Lipids• Nucleic acids
2.02 Investigate and describe the structure and functions of cells including:• Cell organelles• Cell specialization• Communication among cells within an organism.
2.03 Investigate and analyze the cell as a living system including:• Maintenance of homeostasis• Movement of materials into and out of cells• Energy use and release in biochemical reactions

8© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

2.04 Investigate and describe the structure and function of enzymes and explain their importance in biologicalsystems.
2.05 Investigate and analyze the bioenergetic reactions:• Aerobic Respiration• Anaerobic Respiration• Photosynthesis
Competency Goal 3:
The learner will develop an understanding of the continuity of life and the changes of organisms over time.
Objectives
3.01 Analyze the molecular basis of heredity including:• DNA replication• Protein synthesis (transcription, translation)• Gene regulation
3.02 Compare and contrast the characteristics of asexual and sexual reproduction.
3.03 Interpret and predict patterns of inheritance.
• Dominant, recessive and intermediate traits• Multiple alleles• Polygenic inheritance• Sex-linked traits• Independent assortment• Test cross• Pedigrees• Punnett squares
3.04 Assess the impact of advances in genomics on individuals and society.
• Human genome project• Applications of biotechnology
3.05 Examine the development of the theory of evolution by natural selection including:• Development of the theory.
• The origin and history of life.
• Fossil and biochemical evidence• Mechanisms of evolution.
• Applications (pesticide and antibiotic resistance)
Competency Goal 4:
The learner will develop an understanding of the unity and diversity of life.
Objectives
4.01 Analyze the classification of organisms according to their evolutionary relationships.
• The historical development and changing nature of classification systems• Similarities and differences between eukaryotic and prokaryotic organisms• Similarities and differences among the eukaryotic kingdoms: Protists, Fungi, Plants, Animals• Classify organisms using keys
4.02 Analyze the processes by which organisms representative of the following groups accomplish essential life
functions including:• Unicellular protists, annelid worms, insects, amphibians, mammals, non vascular plants, gymnosperms
and angiosperms• Transport, excretion, respiration, regulation, nutrition, synthesis, reproduction, and growth and development
4.03 Assess, describe and explain adaptations affecting survival and reproductive success.
• Structural adaptations in plants and animals (form to function)• Disease-causing viruses and microorganisms• Co-evolution© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

94.04 Analyze and explain the interactive role of internal and external factors in health and disease:• Genetics• Immune response• Nutrition• Parasites• Toxins
4.05 Analyze the broad patterns of animal behavior as adaptations to the environment.
• Innate behavior• Learned behavior• Social behavior
Competency Goal 5:
The learner will develop an understanding of the ecological relationships among organisms.
Objectives
5.01 Investigate and analyze the interrelationships among organisms, populations, communities, and ecosystems.
• Techniques of field ecology• Abiotic and biotic factors• Carrying capacity
5.02 Analyze the flow of energy and the cycling of matter in the ecosystem.
• Relationship of the carbon cycle to photosynthesis and respiration• Trophic levels — direction and efficiency of energy transfer
5.03 Assess human population and its impact on local ecosystems and global environments.
• Historic and potential changes in population• Factors associated with those changes• Climate change• Resource use• Sustainable practices/stewardship10© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

From Finches to Fishes
Correlation to the National Science Education Standards
The Teaching Standards
From Finches to Fishes Correlation
Each activity in the module provides short-term objectives for students. Thereis a conceptual flow of activities and a timeline for teaching the module andhelping teachers plan.
Use of this module helps teachers to update their curriculum in response to
student interest in the topic.

Standard A: Teachers of science plan an inquiry-based science program
for their students. In doing this, teachers• develop a framework of yearlong and short-term goals for students.
• select science content and adapt and design curriculum to meet the interests, knowledge, understanding, abilities, and experiences of students.
• select teaching and assessment strategies that support the development ofstudent understanding and nurture a community of science learners.

The module’s focus is active, collaborative, and inquiry-based.
Student inquiry is encouraged by all activities in the module.
The module promotes discourse among students, and challenges students toaccept responsibility for their own learning by using hands-on, inquiry-based
activities.
The use of the 5E instructional model with collaborative learning is an effective way of responding to diversity in student backgrounds and learning styles.

There are a variety of assessment components provided in the module, such asgroup discussion, data collection, and student writing.
Answers are provided to help teachers analyze student feedback.

The answers provided for teachers model respect for the diverse ideas, skills,
and experiences of all students.
Students work collaboratively in teams to complete activities in the module.
Discussion activities in this module model the rules of scientific discourse.

Standard B: Teachers of science guide and facilitate learning. In doing
this, teachers• focus and support inquiries while interacting with students.
• orchestrate discourse among students about scientific ideas.
• challenge students to accept and share responsibility for their own learning.
• recognize and respond to student diversity and encourage all students toparticipate fully in science learning.
• encourage and model the skills of scientific inquiry, as well as the curiosity,
openness to new ideas and data, and skepticism that characterize science.
Standard C: Teachers of science engage in ongoing assessment of theirteaching and of student learning. In doing this, teachers• use multiple methods and systematically gather data about student
understanding and ability.
• analyze assessment data to guide teaching.
Standard E: Teachers of science develop communities of science learners
that reflect the intellectual rigor of scientific inquiry and the attitudes
and social values conducive to science learning. In doing this, teachers• display and demand respect for the diverse ideas, skills, and experiences ofall students.
• structure and facilitate ongoing formal and informal discussion based on ashared understanding of rules of scientific discourse.
• model and emphasize the skills, attitudes, and values of scientific inquiry.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

11

From Finches to Fishes
Correlation to the National Science Education Standards
The Content Standards
From Finches toFishes activity

Pre-lab Activities
Wet-lab Activities

Pre-lab Activities

Standard A (Science as Inquiry) : As a result of activities in grades 9-12, all students should develop
1. abilities necessary to do scientific inquiry.
• Identify questions and concepts that guide scientific investigations• Use technology and mathematics to improve investigations and communications• Formulate and revise scientific explanations and models using logic and evidence• Recognize and analyze alternative explanations and models• Communicate and defend a scientific argument• Understand about scientific inquiry
Standard C (Life Science): As a result of their activities in grades 9-12, all students should develop understanding of
1. the cell.
• Cells store and use information to guide their functions• Cells can differentiate, and complex multicellular organisms are formed as a highly organized arrangement ofdifferentiated cells
2. molecular basis of heredity.
• In all organisms, DNA carries the instructions for specifying organism characteristics• Changes in DNA occur spontaneously at low rates

Pre-lab Activities
Wet-lab Activities

3. biological evolution.
• Species evolve over time

Additional Activities

Pre-lab Activities
Wet-lab Activities
Post-lab Activities

Wet-lab Activities
Post-lab Activities

12Standard E (Science and Technology): As a result of activities in grades 9-12, all students should develop understanding of
2. Understandings about science and technology.
• Scientists in different disciplines ask questions, use different methods of investigation, and accept different types of evidence
to support these explanations• Science often advances with the introduction of new technologies• Creativity, imagination, and good knowledge base are all required in the work of science and engineering• Science and technology are pursued for different purposesStandard F (Science in Personal and Social Perspectives): As a result of activities in grades 9-12, all students should
develop understanding of
1. personal and community health.
5. natural and human-induced hazards.
6. science and technology in local, national, and global challenges.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

INTRODUCTION
Teaching evolution as an inquiry process
presents a challenge for educators. Traditionally students have used printed materials
to learn about how organisms evolve. This
module encourages students to explore theconcepts of evolution using a more active,
discovery-based approach.

KEY
CONCEPT
We often hear
natural selectionreferred to as“survival of thefittest.” “Fittest”
means thatorganisms must
not only survive
to adulthood, butthey must actually
reproduce.

Students are actively engaged in learning
throughout this module. An interactive, largegroup discussion helps to evoke and reinforce
learning outcomes. During each phase of thelesson, the teacher assesses the knowledge
gained by students by listening to the adequacy of their viewpoints. Enabling students
to understand the practical implications ofevolution is not an easy task. It necessitates
overcoming apprehensions, misunderstandings, and incorrect scientific information thatcreate barriers that keep students from being
open to ideas.
To simulate a real trip experience to an undisclosed location (the Galapagos Islands), students are provided sunglasses, bandanas andtravel information, including a map, picturesof flora and fauna found on the islands, and adeparture checklist. Additional travel information is provided by a tour guide ― the teacher― using a PowerPointTM presentation.
Next on the agenda is a “fishing expedition,”since fishing is one of the islands’ major tourist
attractions. To better understand the process ofevolution, students use the bandanas as blindfolds, as they play the role of predatory fish
whose favorite “food” is acetate “animals.”
The wet lab moves beyond DNA and utilizes
one of the most widely used techniques inbiotechnology research, protein gel electrophoresis. This provides a more conceptual
approach for teaching biological evolution
in an empirical fashion. Students can use
protein electrophoresis to investigate molecular variations and examine evidence forbiological evolution and common ancestry. In
addition students are introduced to thescience of proteomics, the study of the function, structure and interaction of proteins witheach other and their environment. Additional

Water-color portrait of a young Charles Darwin, painted by
George Richmond in the 1830s.
activities include computer-based bioinformatics activities specifically developed forthis lab. These activities allow students tounderstand the power of databases and how
they are used in scientific research.

DARWIN’S THEORIES OF EVOLUTION
The observations made by Darwin on his trip
to the Galapagos set the stage for the development of the theory of evolution by natural
selection, which was set forth in his famous
publication, The Origin of Species.
It is important to note that Darwin was but
26 years old when he visited the Galapagos
Islands. He boarded the H.M.S. Beagle at theage of 22 as an unpaid observer. His credentials at that time were not very impressive. He
was a medical school dropout from Edinburgh University and a noticeably uninspired
divinity student. Prior to visiting the Galapagos, the Beagle spent three years surveying
the shores of South America and spent only abrief five weeks (September-October, 1835)
stay on the Galapagos Islands.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

13Charles Darwin developed the theories of
evolution using information from several
disciplines. He observed and was impressedby the amount of variation within a species, especially domestic animals. He spenta great deal of time studying cattle breeding
programs. Darwin was familiar with artificial
selection or choosing plants and animals withdesirable characteristics.

DID YOUKNOW?
Early embryos ofmany different
vertebrate species
look remarkably
similar.

Darwin’s first theory — descent with modification — states that newer forms appearing
in the fossil records are actually the modified
descendants of older species. Darwin’s
second theory — modification by natural
selection — states how evolution occurs.
The key factor in natural selection is theenvironment, which presents challenges that
individuals with particular traits can better overcome. Thus the environment selects
which organisms will survive and reproduce
more often. These organisms are considered
to be best adapted to their environment.
Darwin’s theory of evolution by natural selection can be summarized in four statements:
1. Variations exist among individual
species.
2. Organisms produce more offspringthan the environment can support.
3. Competition exists among individuals.
4. The organisms whose variations best

adapt them to the environment are theones who are most likely to survive,
reproduce, and pass those desirable
variations on to the next generation.
Evolution can also be defined as a change inthe frequency of a trait (gene) within a population. Changes in gene frequency occur only
when variations are passed along throughsucceeding generations. Evolution could notoccur without genetic variation. The ultimate
source of variation can now be understood aschanges in the DNA caused by mutation orsexual recombination.

SPECIATIONOver time mutations can lead to speciation.
A standard definition of a species in animals
is organisms that have the ability to interbreed and produce fertile offspring. Speciation or the development of a new species may
occur in several ways:• Isolation mechanisms may result froma geographical barrier, or other kinds ofbarriers, which prevent interbreeding
between the two resulting populations.
Genetic drift occurs when a resulting
population is very small; some genes will
increase or decrease strictly by chance.
For example, one of the founding members of the small group of Germans thatbegan the Amish community in Pennsylvania possessed an allele for polydactylism (more than five fingers or toes on a

Fossils of extinct species provide evidence for evolution.

14© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

The wings of birds and insects are an example ofanalogous structures: They serve the same functions
and look similar, but developed from different origins.

limb). After 200 years of reproductive
isolation, the number of cases of this trait
among the 8,000 Amish exceeded thenumber of cases occurring in the remaining world’s population. Other types ofisolation mechanisms include:◦ Habitat isolation, which occurs when
species do not encounter one anotherbecause they live in different habitats.
◦ Temporal isolation, which occurs
when species breed during different
seasons, different times of the day, oreven different years.
◦ Behavioral isolation, which exists
when there is little or no sexual attraction between females and males
because the potential mates do not
perform the correct courtship rituals,
display the proper visual signals,
sing the correct mating songs, or
release the proper chemicals (scentsor pheromones).
◦ Mechanical isolation, which occurs
when male and female sex organs
are structurally incompatible.
◦ Gametic isolation, which occurs
when a male and female mate but

Animals Being Compared

Number of Amino
Acid Differences
In Cytochrome C

Human and chimpanzees

0

Human and rhesus monkeys

1

Humans and dogs

13

Humans and rattlesnakes

20

Humans and tuna31

the gametes do not form a zygote
because the male gametes do notsurvive in the environment of thefemale gamete.
• Adaptive radiation is relatively rapid
evolution of many species from a single
ancestor. It occurs when the ancestral
species colonize an area where diverse
geographical or ecological conditions areavailable for colonization.
◦ Example: The fourteen species ofDarwin’s finches on the Galapagos
Islands evolved from a single ances-© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

15

tral South American species. They
diverged in response to the availability of different types of food in theirdifferent habitats.

EVIDENCE FOR EVOLUTION
The following fields provide the evidence for
evolution:• Paleontology provides fossils revealing the prehistoric existence of extinct
species and that organisms have evolvedin a chronological sequence. As a result,changes in species and the formation of
new species can be studied.
• Biogeography uses the geographic
distribution of species to explain how unrelated species in different regions of theworld look alike when found in similar
environments.
• Embryology reveals similar stages indevelopment (ontogeny) among related
species. The similarities help establish
evolutionary relationships (phylogeny).
Early embryos of many different vertebrate species look remarkably similar.
• Comparative anatomy uses the comparison of body structures in different species
as evidence for evolution. Homologous
structures are anatomically similar features that originated in a shared ancestor.
An example would be the forelimbs of
the penguin, alligator, bat, and human, allof which derived from the same embryological structures. Analogous structures
serve identical functions and look somewhat alike, but have different origins. An
example would be the wings of a bird andthe wings of an insect.
• Molecular biology examines nucleotide
and amino acid sequences of DNA andproteins from different species.
• Evolutionary biology compares different
living organisms to one another and to
fossil forms to get an understanding of
how individual species arose from earlier
forms and what mechanisms gave rise to
the changes involved.

16

DNA AND DIVERGENCE
The tools of molecular biology have made it
possible for scientists to compare DNA andprotein of different organisms, in addition totheir morphology. The rationale for using information about proteins to make inferences
about evolution is based on the fact that DNA
sequences, genes and their corresponding
protein sequences are inherited. Species
diverge through changes in their DNA sequences. These mutations can lead to changes
in the amino acid sequences of proteins. The
longer two species diverge from a common ancestor, the more differences in DNA
and protein they will accumulate. Thus, thedegree of relatedness of two species can be
estimated from the degree of similarity or differences of their DNA or protein sequences.
In order to make a comparison of protein
sequences, scientists assemble the amino acidsequences of a single protein or a group of proteins from the species in question. Next, theycount the number of amino acid differences.
The more differences, the longer ago the two
species diverged and subsequently the degreeof their relatedness is reduced. The degree ofrelatedness can be determined more precisely
by comparing large groups of protein.
Evolutionary biologists use this comparative
information along with data from the fossil
records to estimate when lineages leading
to various modern species diverged from acommon ancestor. A common misconception is that humans descended from apes. In
evolutionary terms, humans and apes eachbranched from a common ancestor about
5 million years ago. Humans are related toapes but did not descend from them.

PRE-LABStudents use a discovery-based approachto understanding the concepts of evolution
by taking an imaginary journey to an undisclosed destination (the Galapagos Islands).
They become totally involved in the discovery process by examining the plant andanimal life on the islands as well as thephysical characteristics of the islands.
Students develop an understanding of the di-© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

Students will take an imaginary trip to the Galapagos Islands during the pre-lab, following in Darwin’s footsteps.
versity of plant and animal life, and discover
species unique to this destination.
To simulate a real trip experience, students
are given sunglasses, bandanas and travel
information which includes maps, picturesof the flora and fauna found on the islands,
and a departure checklist. Additional travel
information is provided by a tour guide — theteacher — using a PowerPoint presentation
which contains vivid pictures of the landscape, plants, and animals.
Next on the agenda is a “fishing expedition,”since fishing is one of the major tourist attractions of the area. To better understand the process of evolution, students are asked to become
predatory fish whose favorite food is “acetate
animals.” Not only are students able to develop
an understanding of the predator-prey relationship, they also compile and examine the datafrom the class and determine the frequency of
selection of a particular animal trait.
Students end their journey by returning homefrom their memorable trip with a figurative
backpack full of information and many
examples of lessons learned on their expedition. “Unpacking” from the trip leads toa discussion of vocabulary, evolutionary
processes, and scientific concepts related toevolution by natural selection. During eachphase of the lesson, the teacher assesses theknowledge gained by students by listening
to the adequacy of their viewpoints. One of
the items students unpack upon returning isa small treasure chest that was found on theirtrip to the Galapagos. When students open thechest they find a treasure consisting of small
strips of paper containing examples of findings from their expedition. The strips of paperin the treasure chest will provide the answers
students need to complete an assignment theteacher gives them prior to taking the trip to
the Galapagos.

WET-LAB
Proteins are instrumental in almost everything cells do. They are used for structural
support, storage, transport of substances,signaling from one part of the organism toanother, and movement and defense against
foreign substances. In addition, as enzymes,
proteins selectively accelerate chemical
reactions in cells. Proteins determine form
and function and consequently serve as theraw materials of evolution.
The wet-lab provides students the opportunity to perform polyacrylamide gel electrophoresis to separate proteins and to compare
the protein profiles of closely and distantly© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

17related species of fish. Students have an
opportunity to view evolution from amolecular standpoint. In gel electrophoresis,
separation of charged molecules is achievedby subjecting the charged molecules to anelectric current that forces them to migrate
through a matrix (the gel).
The behavior of molecules during gel electrophoresis depends on their size, shape, andnet charge, and proteins vary greatly in allthese areas. To make protein migration rates
a function of molecular weight, it is necessary to impose a uniform shape and charge
on all proteins in a mixture. This goal can beachieved by treating the protein mixture withthe detergent sodium dodecyl sulfate (SDS)
and heat, which disrupt all the hydrogenbonds maintaining the protein’s three-dimensional shape. If the sample is simultaneously
treated with a reducing agent such as betamercaptoenthanol, disulfide bridges will
also be broken, leaving the protein a linear
chain of amino acids. The SDS binds to theprotein backbone without regard to amino
aid sequences, imparting a uniform negative
charge to the molecules. Under these conditions, all the proteins in a mixture assume auniform shape and charge. During electrophoresis, proteins migrate toward the positivepole at a rate proportional to their molecularmass. To best observe results, this module
requires the use of Bio-Rad’s Comparative
Proteomics Kit I: Protein Profiler module
and Ready Gel® precast polyacrylamide gels.
The fish protein samples are easily obtained
from a local grocer or market and prepared
before the lab. During the lab the students
load five fish samples, an actin and myosin
standard sample, and Precision Plus ProteinTM
KaleidoscopeTM prestained standards in thedesignated gel wells of a vertical electrophoresis chamber. After running, the gels arethen stained and destained overnight, so thatstudents can analyze the results the next day.

POST-LAB/ADDITIONAL ACTIVITIESThe post-lab activities are designed to help
reinforce the concepts of protein fingerprinting and to help students analyze andcompare the banding patterns formed from18

During the wet-lab, students will examine the evolution offish from the standpoint of molecular biology.
the electrophoresis of the five fish samples.
Students compare the similarities and differences between the banding patterns and makeinferences as to which fish could be moreclosely related. They incorporate the idea thatthe more similar the bands, the more closely
related the fish, based on the relationshipbetween DNA and proteins in an organism.
Teachers will remind students that gel electrophoresis of proteins does not provide any
direct information about amino acid sequences
and so cannot be used in a precise way toreconstruct evolutionary history. The overall
protein fingerprints obtained from different
species are more similar when closely related
species are compared. Students will discoverthat these similarities are consistent with theproposed fish evolutionary tree.
Additional post-lab activities help students
review key evolutionary concepts from thepre-lab and wet-lab activities. The DESTINY
Quiz Game provides a fun evaluation activity that allows students to demonstrate theirknowledge in the style of the popular TV
game “Jeopardy.” Teachers are provided a
computer program that can project the gameboard onto a screen to allow for interactive
play or they can use printed versions of thequestions and answers in class. Another postlab activity is the first video, “Isn’t Evolution© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

Just a Theory,” from the PBS evolution series, Learning and Teaching Evolution, which
combines storytelling with science content.
Teachers can choose to show the video toprovide closure to a class discussion or prior
to an activity that involves students writing
an essay in which they can apply vocabulary,evolutionary process, and scientific concepts.
A rubric is even provided to help teachersscore the essay.
The additional activities included in thismodule were designed to augment the pre-,wet-, and post-labs. The exercise entitled
Using Databases to Obtain Real Amino
Acid Sequence Data to Create Cladograms
provides teachers with an activity for moreadvanced students. There are also activities that allow for interactive learning fromvarious websites. The Peppered Moth Game,
Chromosome Connections, Building Bodies,and others are all exciting ways for students
to use the Internet and receive immediate

feedback on issues relating to evolution.
Students can also access online lessons andan interactive website from PBS that can beused in conjunction with the video.
Interdisciplinary activities and additional
resources are also provided. Dr. Amber
Vogel’s Picture This is a wonderful writing and listening exercise for science andnon-science classrooms that allows students
to explore their feelings about evolution.
This activity is recommended as a starting
point for the evolution unit in a biology classand for science and non-science teachers towork cooperatively to incorporate evolutionthemed work into other assignments.
The use of any or all of these post-lab
and additional activities will provide
teachers with a variety of ways to evaluate
student understanding of concepts coveredin the module and as a link to real world
applications.

BACKGROUND
From Bio-Rad’s Comparative Proteomics Kit I: Protein Profiler Module
EVOLUTION
The term evolution probably brings to mind
Charles Darwin and the theory of natural
selection and common descent. The observation that every species on the planet, including humans, produces far more offspring ineach generation than nature can support andthat the pressure of so much excess population is a harsh but efficient test of the value ofaccidental variations in any species was thecentral observation that underlies Darwin’s
theory. As such, all species change gradually
over time through natural selection. Each ofthese individuals is different — even among
the same species. The environment selects
organisms best suited to survive and reproduce based on those differences. Adaptations
are the differences that make one organism
more suited to the environment than anotherindividual. These adaptations are phenotypic(physical) characteristics such as the variations in finch beaks that are determined by agenetic component. The genetic component
is inherited from the parent in the form ofgenes.

The discovery of the chemical structure of
DNA gave us an understanding of how thetriplet code of nitrogen bases allows thesynthesis of proteins (which is the phenotypic
expression) and how phenotypic adaptations
are the result of changes in the DNA code
(mutations).
However, current research in the field of proteomics is leading some scientists to question
whether or not DNA is the final determining
factor in the synthesis of proteins and thus thedetermining factor in evolution.
The central dogma of molecular biology(DNA → RNA → protein) has given us acomfortable explanation of how the information encoded by our DNA is translated
and used to make an organism. It describes
how a gene made of DNA is transcribed bymessenger RNA and is then translated into a
protein by transfer RNA in a complex seriesof events utilizing ribosomal RNA and aminoacids. New discoveries about alternativeroles for RNA, multiple forms of proteins
being encoded by single genes in our cells,© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

19ON THEWEB
The Human
Genome Project
www.ornl.gov/
sci/techresources/
Human_Genome/
home.shtml

and changes to proteins after translation arechanging this comfortable scenario and weare finding that things (as ever in biology)
are not so simple. Although in essence thecentral dogma remains true, investigations
into genomics and proteomics are revealing acomplexity that many had never imagined.

esized that a large amount of the exogenous
noncoding DNA in the human genome functions to highly regulate protein production,
expression levels, posttranslational modifications, etc. and it is this regulation of ourcomplex proteomes, rather than our genes,
that makes us different from worms.

In 1990, a massive research effort took place
to sequence what was estimated to be the100,000 genes that coded for each protein
synthesized by humans (the human genome).

Researchers in the proteomics field havediscovered a number of modification systems
that allow one gene to code for many proteinsand mechanisms that finely regulate the suband extracellular locations and expression
levels of proteins. These include alternative
splicing of exons, use of different promoters,
posttranscriptional modification, translationalframeshifting and posttranslational modification. Let’s examine some of these systems.

This study, the Human Genome Project, took
13 years to complete (Jasny and Kennedy,2001). When the study began, scientists estimated that there were over 100,000 humangenes. Now, years after the genome has beensequenced, there is still no consensus on theactual number of human genes, but the current estimate is down to around 22,000 human genes; this is only a few thousand moregenes than encodes the genome of a much
simpler organism, C. elegans, a nematodeworm that has around 19,000 genes.
So why are a similar number of genes required
to make a worm and a person? Importantly,
a human has a much larger total genome (3billion base pairs) than a worm (100 million
base pairs), suggesting that the total amount of
DNA rather than the actual number of genes
may be what gives rise to complexity. In
addition, recent developments have shown it
is quite common in complex organisms for asingle gene to encode multiple proteins.
Moreover, changing when, to what level andwhere a protein is expressed or changing aprotein after it has been translated (posttranslational modification) can result in proteins
with very different functions. This realizationof the importance and diversity of proteins
started a whole new field termed proteomics.
Proteomics was initially defined as the effort to catalog all the proteins expressed in
all cells at all stages of development. That
definition has now been expanded to include
the study of protein functions, protein-protein
interactions, cellular locations, expression
levels, and posttranslational modifications of
all proteins within all cells and tissues at allstages of development. Thus, it is hypoth-

20

POSTTRANSCRIPTIONAL MODIFICATIONS• RNA Editing
A newly discovered form of posttransciptional modification is RNA editing. Higher eukaryotes can change the sequenceof their messenger RNAs (mRNAs)by substituting bases in their primarymRNA transcripts at specific positions,while lower eukaryotes insert and delete
specific bases. These types of changes
to the codons of mRNA can change theamino acid sequence of a protein, create
a new open reading frame where one did
not originally exist, or introduce a newstop codon to create a truncated protein.
These changes can be regulated by thelocation of their expression, developmentally and by the organism’s environment,
and the resulting proteins can have very
different functions. For example, fastingrats produce 50% less of an edited formof apolipoprotein B (a protein involvedin cholesterol metabolism) than rats on ahigh carbohydrate diet (Maas and Rich,
2000). This happens when a cytidine
is substituted with uridine. These basesubstitutions happen at specific locations,indicating they are involved in the regulation of metabolism.
RNA editing is not limited to messenger
RNA. In a number of yeast and higher
eukaryotes, transfer RNA is also edited
at the wobble positions of its anticodons(Maas and Rich, 2000).

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

• Alternative Splicing
Messenger RNA (mRNA) of higher
eukaryotes has two types of sequence
segments — introns and exons. Introns
are portions of the code that are removed
or edited from the sequence to be transcribed into protein. The remaining basesegments, exons, move to the ribosome
for translation. Exons can be differentially included or excluded in a process
called alternative splicing to produce
different mature mRNAs, which in turngenerate distinct proteins. This process
can be used at different stages in development or simply when a cell is signaled
to alter its protein production.
• mRNA Synthesis and Degradation
Since the level of mRNA within a cellin part determines the level of protein
expression, the rate at which mRNA is
synthesized and the rate at which mRNAis degraded are important factors inprotein expression levels. Some mRNAs
are inherently more unstable than others
and there are active processes withincells that regulate mRNA’s degradation
as well as its synthesis. Modifications tomRNAs can also change their stability
and thus their levels of protein expression. For example, capping an mRNA
with a 7-methyl guanosine nucleotide
and the presence of a polyadenosine tailincreases its stability. As such, the regulation of mRNA by capping and polyadenylation increase protein expression.

POSTTRANSLATIONAL MODIFICATIONS• Proteolytic Cleavage
Most proteins undergo cleavage after
translation: the simplest form of this is
the removal of the initiation methionine.
In addition, many enzymes are regulated
by proteolytic cleavage and are either
activated or inactivated (or both) bycleavage of specific domains within theprotein. Examples of this are the procollagenases that digest extracellular matrix
collagens only after the removal of their“pro” domain. Protein cleavage resultsin different proteins of different sizes
derived from the same gene.

• Protein Degradation
Similar to mRNA synthesis and degradation, proteins are actively regulated bydegradation mechanisms. Proteins havespecific half-lives and these can be regulated by posttranslational modifications.
In one mechanism, that won its elucidators the 2004 Nobel Prize in Chemistry,
proteins are tagged with ubiquitin proteins and degraded in highly regulated
cellular degradation machinery known asproteasomes. By regulating the degradation of its proteins, a cell can quickly
change the levels, as well as the presenceor absence of a protein in response tooutside factors.
• Protein-Protein Interaction
Many proteins exist in complexes andthe presence or absence of other proteinsfrom these complexes can determine
their function. Thus proteins are dependent on other proteins for their activity.
Although a specific protein may be present in abundance, if its binding partner isin short supply, then the protein will havelittle, if any, activity.
• Carbohydrate Modification (Glycosylation)
Many proteins, especially those associated with the plasma membrane andthose that are secreted, are covalently
bound to carbohydrates – usually sugars.
Carbohydrate modification drasticallychanges the way proteins behave andinteract with other proteins or structures
and act as targeting molecules to direct
proteins to specific locations within theorganism or cell. Lymphocytes (whiteblood cells) have carbohydrate groups
on their outer membranes which arevital in determining how lymphocytes
infiltrate sites of infection. Carbohydrate
modifications can result in proteins withdifferent molecular weights and different
physio-chemical properties derived fromthe same gene.
• Phosphorylation
Many proteins are regulated by phosphorylation. Most phosphorylation
reactions change the activity of enzymes,
often by causing conformational changes© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

21within the protein. This is the case withmyosin light chain 2 or myosin regulatory light chain, which contracts smoothmuscle when phosphorylated. There is a
special class of enzymes that phosphorylate proteins called kinases, and theircounterparts, which dephosphorylate
proteins are called phosphatases. Many
proteins are phosphorylated on multiple
sites, and each phosphorylation site hasa specific role in the function or activity
level of the protein. Thus a protein may
exist in many different states of activity depending on which sites have been
phosphorylated.
Other forms of posttranslational modification
include methylation, sulfation, prenylation
and acetylation.
Based on this new research, proteomic researchers can feasibly argue that it becomesincreasingly important to examine differencesin the proteins being expressed in different
species just as it is important to examine differences in DNA code. Phenotypic diversity isachieved with little cost. Life shows amazing
economy when one gene can encode many
proteins and these proteins can be subsequently modified to suit a particular environment.

22

Imagine the flexibility of an organism with anextensive RNA editing system! We previously thought protein sequence could only
be changed at the level of DNA mutations,which were rare and occurred randomly, an
adaptation mechanism inherent with highrisk. We are now beginning to understand that
there are indirect forces, in addition to genemutation, that can drive evolution. Modifying
an RNA editing system to change a protein
complement would be far less risky thanirreversibly changing the genes encoding
proteins themselves since edits are optionaland reversible. Thus an organism would havemuch more flexibility to adapt to new anddifferent environments. Mounting researchsuggests that the number of RNA editing systems is great and that the similarity in thesesystems may be of evolutionary significance.
In the Comparative Proteomics Kit I: Protein
Profiler Module we focus on comparing theproteomes of muscle cells and the differences in these proteomes between distantly
and closely related species. The differences
found can then be used to determine, or infer,evolutionary relationships between different
species.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

CONNECTION TO OTHER MODULES
The wet-lab presented here, along with thethree additional wet-lab activities mentioned
below, provides students with first-handexperience of common techniques used bymolecular biologists. Molecular biology examines nucleotide and amino acid sequencesof DNA and proteins from different species.
Because the genetic information in DNA provides the instructions eventually expressed asproteins, alterations in DNA can alter proteinsso that they function differently.

EXPLORING NEW ENVIRONMENTS
Exploring New Environments was developedby DESTINY to enable students to investigate ecosystems andexplore the complex
relationships between
organisms and their
physical environment.
In Finches to Fishes,
students investigate
the ecosystems of theGalapagos Islands.
They identify the floraand fauna of these enchanting islands as they
contemplate interaction between living organisms and their physical environment.

GET A CLUE
In DESTINY’s module Get a Clue, students
use agarose gels and horizontal gel chambers
to separate DNA thathas been cut with arestriction enzyme. The
wet lab in Finches toFishes provides anopportunity for students to increase theirknowledge of molecular biology and refine
their techniques ofelectrophoresis by separating proteins using
precast polyacrylimide gels and vertical gel
chambers.

MYSTERY OF THE CROOKED CELL
The module Finches to Fishes examines the
structure and function of proteins as it relates
to the DNA code. To prepare students for thiscontent, we strongly recommend Mysteryof the Crooked Cell,a module developed
by Boston University
School of Medicine’s
CityLab. In Mysteryof the Crooked Cell,
students examine thegenetic basis for sickle
cell anemia. Students
observe functional
differences in the normal hemoglobin andsickle cell hemoglobin which result from apoint mutation that changes the DNA. In both
modules students perform an electrophoresis
of proteins and examine the changes that
result in the protein as a result of changes inthe DNA.

SEQUENCE OF MODULES
A sequence relating the four modules issummarized below:
1. EXPLORING NEW ENVIRONMENTS
Students investigate complex relationships between organisms and the physicaland biological environment as well as the
movement of materials and energy throughan ecosystem.
2. GET A CLUE
Students learn the structure and functionof DNA. Students learn basic techniquesof DNA gel electrophoresis.
3. MYSTERY OF THE CROOKED CELL
Students learn how changes in DNA
structure lead to changes in protein structure. Students learn basic techniques ofprotein electrophoresis.
4. FROM FINCHES TO FISHES
Students compare protein from themuscle cells of fish to determine whichfish are most closely related. Since DNA
determines protein, those fish whichhave the most similar proteins would be
expected to have similar DNA and similar
origins. This is a more advanced type ofelectrophoresis lab using polyacrylimide
vertical gels to separate proteins.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

23

24

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

FROM FINCHES TO FISHES IMPLEMENTATION PLAN — PRE-LAB
Activity

Engagement:
Imaginary trip to the
Galapagos

Exploration:
Fishing Trip — Go Fish

Explanation

Elaboration:
Discussion of trip —“Backpack of Memorabilia”

Evaluation

Estimated
Time

Materials/Equipment

20 minutes

Travel Package: maps, pictures offlora and fauna, departure checklist,
bandanas, sunglasses, etc.
Group report sheet
CD — PowerPoint presentation/tour
guide script

20 minutes

Blindfolds, acetate sheets (two colors)
Go Fish activity sheet
Tally sheet
Calculators

20 minutes

Data table
Discussion questions

20 minutes“Memorabilia backpack” consisting oftravel packet, CD PowerPoint (2nd part)with discussion questions, and groupreport sheet
Paper people models

10 minutes

Small treasure chest
Answer strips — placed in the treasure
chest
Evaluation questions sheet
NOTE: For higher-level classes, consider
using the essay and rubric from theAdditional Activities section instead.

Purpose/Objectives/
Essential Question

Purpose:To examine the process of evolution
by natural selection. To discover
the features, wildlife, and scientificsignificance of the Galapagos Islands
in relationship to the study of natural
selection.

Objectives:• To define evolution• To discuss predator-prey
relationships• To understand the mechanismsthat bring about change• To examine the process of speciation and geographic isolation• To provide evidence that supports
the theory of evolution by means of
natural selection

Essential Question:
How does natural selection work tocreate new species?

Alignment with NC Competency Goals
Biology
Goal 1
Objectives 1.01, 1.02, 1.03
Goal 2
Objectives 2.01, 2.02, 2.03

Goal 3
Objectives 3.01, 3.04, 3.05
Goal 4
Objectives 4.01, 4.02, 4.03
Goal 5
Objective 5.01

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

25

FROM FINCHES TO FISHES PRE-LAB ACTIVITIES:UTILIZING THE 5E INSTRUCTIONAL MODELENGAGEMENT
Working in teams, students will become explorers as
they take an imaginary trip to an undisclosed destination(only the teacher knows it’s the Galapagos Islands).
Each student will receive a bandana anda pair of sunglasses for the trip. Teachers are encouraged to take a group photo,
representative of an actual group trip to an
exotic location. Each student group will be presented
with a travel package that includes maps, pictures ofthe flora and fauna found on the island, and a departurechecklist. These items will provide clues to assist
students in naming their final destination. A Group
Report Sheet is provided for possible explanations orquestions about features, location, wildlife, and thescientific significance of the destination to be visited.
A PowerPoint presentation consisting of pictures fromthe Galapagos and a tour guide script is available on themodule CD for teacher use. In addition Questions fromGroup Report Sheet; Imaginary Trip to the Galapagos isprovided for additional information on the Galapagos.

EXPLORATION
One of the key tourist attractions of the islands is fishing.
To enable students to better understand the process ofevolution, they are asked to become predatory fish whose favorite “food” is acetate“animals.” Students are blindfolded andled into an adjacent lab room where they
become predatory fish that have a limited
period of daylight to search for their prey (blindfolds
are removed for 10 seconds); they must catch as many
as possible before the sun goes down. After sundown,
predators leave the adjacent lab room, take off theblindfolds and determine the number of each type of“acetate animal” remaining.

EXPLANATION
Upon completion of the Go Fish activity, theclass will complete the data table together.
Each group will be asked to present an oralsummary of its findings. Their presentations will provide a launching pad to present scientificexplanations and terminology. Questions to be addressed
are as follows:
. ...
...
... ...
....
..... ....
..........
....
. ....
..
..... ...
... ...
....

. .... ..

1. Did one color of acetate “animal” have an
advantageous variation?

26

2. What happened to the frequency of the clear
color? Why?
3. How might Darwin have explained the change in
the acetate “animal” population?
4. How would you define evolution?

ELABORATION
Students return home from a memorable
trip with a backpack filled with memoriesof their journey. As they unpack their bag
they pull out of the backpack (pictures anddescriptions) many examples of lessons learned on their
expedition.
During this elaboration phase, students have an opportunity to correctly use technical vocabulary andapply scientific reasoning. The instructor will lead a
discussion related to the class’s findings. Some of theconcepts to be discussed are as follows:• Environment and conditions for survival• Relatedness vs. common ancestor• Descent with modification• Adaptive radiation• Modification by natural selection• Isolating mechanisms• Evidence for evolution• Genetic drift• Adaptations, fitness• Extinction• Variations, sources of variation• Species, subspecies and speciation process

EVALUATION
During each phase of the lesson, the teacher will assess
the knowledge gained by students by listening to the adequacy of their viewpoints. One of the items
students unpack from their bag is a small
treasure chest which was found on their trip
to the Galapagos. When students open up
the chest they find treasure that consists ofsmall strips of paper containing examples of findings
from their expedition.
The strips of paper in the treasure chest will provide
the answers students need to complete an assignment
given them by their teacher prior to taking the trip to the
Galapagos.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

ENGAGEMENT ACTIVITY: THE TRIP — PREPARE FOR DEPARTURE
MATERIALS NEEDED• 1 bandana and 1 pair of inexpensive sunglasses for each student• (optional) Polaroid camera and film to takepictures of each group• 1 travel packet for each group of four

NOTE FORTEACHERS
Do not reveal
to the students
the destination(the Galapagos
Islands) since
they will makeobservations andnotes from theinformation given
to them.

To create travel packets, place into a
pocket folder color printouts of pages
29-34 of this module, which contain: amap with a checklist titled Prepare for
Departure, pictures of the flora and fauna
found on the island (place these sheets inplastic sheet protectors to prolong use),
and a Group Report Sheet. All items areavailable on the CD accompanying themodule.
• PowerPoint presentation part one (available
on module CD)• Narrative for PowerPoint Presentation script

INSTRUCTIONS FOR TEACHERS• Working in groups, the students will
become explorers as they take an imaginary
trip to an undisclosed destination. At the
beginning of the class, distribute inexpensive
sunglasses and bandanas to each student in
preparation for the trip activity. You may
choose to build upon the excitement oftraveling to an enchanting island by taking a
picture of the students in each group wearing

sunglasses and bandanas tied around theirnecks for their scrapbook.
• Divide the class into groups of four andprovide each group a travel packet.
• Each group of students should use its Group
Report Sheet to record possible explanationsor questions about physical features, location,
wildlife, and the scientific significance of thedestination to be visited.
• The CD that accompanies this module
includes a three-part PowerPoint presentation; the first part consists of pictures from theGalapagos. Act as a tour guide, showing partone of the PowerPoint presentation to the classwhile reading the script called Narrative forPowerPoint Presentation, Imaginary Trip to
the Galapagos. The script provides interesting
additional information about each picture.
• After finishing the “tour,” give groups a few
minutes to complete their group report using
the information they’ve learned during thepresentation and the materials in their travel
packets. Once the groups have made theirpreliminary report, discuss their findings andquestions as a class. Use the Questions FromGroup Report Sheet: Imaginary Trip to the
Galapagos for additional information on the
Galapagos and to make sure all the questions
the class has generated have been addressed.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

27Pre-lab Materials
Item

Suggested Vendor

Model orCatalog #

Unit

Price

Acetate sheets (clear and gray)*

Office Depot

741361

1 pack

$4.79

Treasure Chests

Oriental Trading**

IN-3/570

dozen

$3.95

Plastic sheet protectors

Staples

489131

100 box$11.89Pocket portfolios

Staples

907701

10 pk

$3.49

1

$12.34

Optional Pre-lab Materials
A Traveler’s Guide to the Galapagos
Islands. Barry Boyce. 4th ed. Aptos
CA; Galapagos Travel, 2004.

www.amazon.com* The acetate sheets are actually poly construction folders that come in packs of 10. Use only the clear and grayfolders. Cut each folder into two 8½” x 11” sheets. Then cut each sheet into 200 squares.
** Also a good source for bandanas and sunglasses.

28© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

The islands are isolated (by several hundred miles of ocean) so the climate is determinedalmost entirely by the ocean currents, which in turn are influenced by the trade winds, whichpush the currents. There are two distinct seasons—one short season with rainfall and anotherlonger season with very little rainfall. Even though the islands are located directly under theequator, the climate is far from being excessively hot, caused singularly by the low temperature of the surrounding water, brought by the great southern Polar current.
TRAVEL NECESSITIES□ Travel documentation —valid passport□ Money — $350.00 (cash andtravelers checks)□ Credit cards□ Telephone calling card
□ Medications
CLOTHING□ Shorts and bathing suits (2 or
3 of each)□ Bed clothes (pajamas, etc.)□ T-shirts (1 week supply)□ Socks□ Underwear□ Sweatshirt, jacket, or sweater□ One pair of pants□ 2-3 shirts or blouses□ Athletic shoes (sneakers) or
hiking boots□ Hat that fits rather snug or
one with an adjustable chinstrap, sweatband□ Toiletries
UTILITY ITEMS□ Binoculars□ Business cards□ Camera and film
□ Daypack (water bottle, bandages, first aid cream, guide-book, film camera), fanny pack
□ Earplugs□ Plastic bags
□ Flashlight/book light□ Rain gear/poncho□ First aid kit□ Sunglasses□ Extra pair of eyeglasses (orcontact lenses)□ Sunscreen lotion□ Vitamins□ Water resistant watch□ Water bottle□ Snorkeling equipment/wet
suit© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

29

Photos from the National Oceanic and Atmospheric Administration/Department of Commerce
Watercolor painting by Owen Stanley

30© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

Iguana photos courtesy of Dr. Bob Rothman (http://www.rit.edu/~rhrsbi/HomePage/homepage.html)
Other photos from the National Oceanic and Atmospheric Administration/Department of Commerce© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

31Lower left photos courtesy of Dr. Bob Rothman (http://www.rit.edu/~rhrsbi/HomePage/homepage.html)
Other photos from the National Oceanic and Atmospheric Administration/Department of Commerce

32© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

Photos courtesy of Dr. Bob Rothman(http://www.rit.edu/~rhrsbi/HomePage/homepage.html)© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

33

GROUP REPORT
Students should take notes from the travel package and from the “tour guide” presentation.

Possible destination ______________________________________________________Your observations during the presentation

Questions you have about the presentation

Physical Factors of the Environment

Physical Factors of the Environment

PlantsPlantsAnimals

Animals

What do you think is the possible scientific significance of this trip?

34© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

NARRATIVE FOR POWERPOINT PRESENTATIONIMAGINARY TRIP TO THE GALAPAGOS
Slide 4: Today we are taking an imaginary journey to an undisclosed destination four hours from Miami. We willvisit a remote paradise 600 miles west of Ecuador, to a small group of 15 islands located on the equator. Formed
3-5 million years ago, these islands are volcanic in origin and are sometimes referred to as the Enchanted Islands.
Slide 5: To get there, we first have to fly to Ecuador, then hop on a boat and sail to the set of mysterious islands. The
cruise ship we’re taking holds 34-90 passengers, and we will visit two islands per day.
Slide 6: Welcome ashore! It’s been a long journey and I’m sure you’re all tired, but we have a lot of exploring to
do. Notice the landscape; it’s rocky, and it appears to be pretty dry and arid. There are black, porous volcanic rocks,
jagged cliff formations, lava fields, pit craters, and columns of gas-driven steam and seascapes. The landscape could
best be described as a moonscape.
Slide 7: As we begin to explore, we are able to see some of the flora of the island. Here we see some prickly pears;
there are 14 different varieties of prickly pears found on these islands.
Slide 8: Again, as we take a look at the landscape, it appears to be rocky and mountainous, and we see a small
cactus growing out of rock formed from a lava flow.
Slide 9: Back at the water’s edge, we see a fur seal. This seems oddly out of place since we are on the equator.
They have large eyes, probably to help hunt for fish and squid.
Slide 10: Also at the water is a sea lion, which also seems to be out of place. Colonies of sea lions are found hereon the gently-sloping rocky shore where they can hunt for fish. The males are larger than the females.
Slide 11: Take a look at the marine iguanas. They are frozen in a pose atop the lava rocks and are sun bathing to
get their body temperatures up. The marine iguana is a very competent diver and swimmer; it is the only lizard
to achieve this ability. It can also sneeze brine out of the efficient salt-excreting glands located in its nostrils. Thisfrequent salt-sneezing gives the marine iguana its white-crested forehead. It looks a lot like other iguanas, but it
behaves much differently. The marine iguana is an avid swimmer, tucking its legs and whipping its body and tailto propel itself through the water. It can stay underwater between 5 to 10 minutes, and dive as deep as 2 meters. It
also has very sharp claws, which it uses to hold onto rocks in the surf while feeding on algae. When a male wants to
attract a female, its black skin turns bright red.
Slide 12: Here is another iguana, but this is a land iguana. Confined to the interior of the island, land iguanas cangrow to over three feet in length, and can live more than 60 years. They actually eat prickly pear cactus, standingon their hind legs to reach the plant. Their tongue is very leathery, and they don’t even remove the spines from thecactus before eating.
Slide 13: Look at the giant tortoise. They look like gentle giants. They are very social creatures. Each island in thisgroup has its own race of giant tortoise. The giant tortoise can have 3 differently shaped shells. They eat large quantities
of grass, leaves, and cactus pads. They are very fond of water, drinking large quantities and wallowing in the mud. Gianttortoises can grow to up to 500 pounds and may live up to 150 years.
Slide 14: Recognize this face? The face of the giant tortoise was used to model ET.
Slide 15: This brightly colored Sally Lightfoot crab shows up pretty clearly on the black lava rock. The Sally lightfoot juveniles, however, are dark in color, camouflaging them against the dark rocks.
Slide 16: This male Magnificent Frigatebird has inflated his throat pouch to about the size of a football to attract amate. He also makes a warbling sound to get her attention. These birds are large and black with long wings, long

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

35hooked beaks, and forked tails. The Great Frigatebird is another species found in this same place.
Slide 17: Penguins? Is this a little unusual? One of the main problems for this penguin is keeping cool living
so close to the equator. The temperature can get over 100 degrees F (38 degrees Celsius) during the daytime. The
penguins hold their flippers out to help the heat escape their bodies. They protect their feet from getting sunburned
by holding their flippers over their feet when on land. They keep cool by swimming and hunting for food in the cold
water of the ocean currents during the day. During the cool nights they sleep and nest on the land. These penguins
eat mostly small fish such as mullet and sardines, which are brought by ocean currents to their feeding grounds.
Slide 18: These blue-footed boobies are some of the most common birds on the islands. The booby in the middle
is “pointing” into the air to attract a mate. The boobies will also “parade” to get a mate. They have a very elaborate
mating dance. Blue-footed boobies will gather nesting materials, only to ignore them later to lay and incubate theireggs directly on the ground. They have really silly behavior and blue feet.
Slide 19: The red-footed booby is just as colorful as the blue-footed booby. The red-footed booby prefers to lay
eggs and hang out in and around trees, making it one of the few seabirds that perch in vegetation.
Slide 20: The masked booby got its name for obvious reasons. This is the biggest species of booby found on theislands, with a wingspan of over 5 feet.
Slide 21: Another bird we see is the enormous albatross, whose wingspan can be over 10 ½ feet. They also have along lifespan and can live about 50 years.
Slide 22: This is a flightless cormorant. It is flightless because it traded in its “flying wings” to make it better suited
for swimming and diving. Flightless cormorants are large, dark-colored, and have a long hooked end on their beak,
which helps them hunt for eels, octopus, and fish.
Slide 23: We also have smaller birds called finches. These islands are home to 13 endemic species of finches,
which are believed to have come from one common ancestor. One of the most prominent features that help us
distinguish finch species is the size and shape of beaks. The unique beak is specifically shaped for the foods eaten,such as insects, flowers, leaves, seeds, and even cactus.
Slide 24: The small tree finch feeds on insects, while the large cactus finch feeds on seeds. Notice the different
shape of their beaks.
Slide 25: It’s been a very busy trip, and we’ve seen a lot. We saw vast numbers of birds and reptiles, but only a few
mammals. If we had gone snorkeling or diving, we would have encountered an undersea world rich with tropicalfish, corals, sharks, eels, rays, dolphins, and more. Now, it’s time for us to return home to reflect on what we saw on
our trip. We have lots of memories that we will want to share with others.

36© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

POSSIBLE QUESTIONS THAT MAY ARISE FROM GROUP REPORT SHEET:IMAGINARY TRIP TO THE GALAPAGOS
These are questions that may arise following the “tour.” Discuss these questions with your students so that they can
add to the group report sheet.
1. How did the seals get here (so far south)?
2. Do seals migrate?
3. Are any of the volcanoes active?
4. What are the temperature extremes?
5. How far are the islands off the coast of Ecuador?
6. Are the islands still growing?
7. Are the pictures we have of extinct or living animals?
8. Do we have the same or different species from island to island?
9. How did the animals get to the different islands?
10. Is the water safe? Clean? Drinkable?
11. What is the elevation of the islands?
12. What is the human population?
13. Would inhabitants need weapons?
14. What is the weather like?
15. What did Charles Darwin find interesting about the Galapagos?
16. What do currents have to do with the dry climate? Why isn’t it hot?
17. Why hasn’t the wildlife evolved past birds and reptiles?
18. What is the volcanic life?
19. What types of mineral deposits exist?
20. What is the impact of human involvement on the Galapagos?

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

37

POSSIBLE QUESTIONS THAT MAY ARISE FROM GROUP REPORT SHEET:IMAGINARY TRIP TO THE GALAPAGOS
1. How did the seals get here (so far south)?
These animals could have crossed the ocean on their own power.
2. Do seals migrate?
Yes, seals do migrate.
3. Are any of the volcanoes active?
Today, the Galapagos are among the world’s most active volcanic areas. There have been 50 eruptions in thelast 200 years, some quite recently. The most recent was in 1995 on Fernandina Island.
4. What are the temperature extremes?
“Considering that these islands are placed directly under the equator, the climate is far from being excessively
hot; this seems chiefly caused by the singularly low temperature of the surrounding water, brought here by thesouthern Polar current. Excepting during one short season, very little rain falls, and even then it is irregular; but
the clouds generally hang low. Hence, whilst the lower parts of the islands are very sterile, the upper parts, ata height of a thousand feet and upwards, possess a damp climate and a tolerable luxuriant vegetation. This isespecially the case on the windward sides of the islands, which receive the moisture from the atmosphere....”— Charles Darwin, Voyage of the Beagle, 1839
One of the keys to understanding the Galapagos is the climate. The islands are isolated by several hundred
miles of ocean, so the climate is determined by the ocean currents, which in turn are influenced by the tradewinds which push the currents. The Galapagos are at a major intersection of several currents, which vary inintensity during the year as their driving trade winds blow and then weaken in a cycle that gives two distinct
seasons to the island.
May-November water temperature 70-75º F.
Dec-April water temperature 75-80º F.
5. How far are the islands off the coast of Ecuador?
600 miles from Ecuador/1000 miles from Central America
6. Are the islands still growing?
Yes, the Galapagos are quite young and are still in early stages of formation. The western islands (Fernandina
and Isabela) are 100,000-200,000 years old. The Galapagos Islands first broke through the ocean floor some
3-5 million years ago. (The Galapagos consist of a chain of 15 islands.)
7. Are the pictures we have of extinct or living animals?
The pictures are of animals that are currently living on the Galapagos Islands.
8. Do we have the same or different species from island to island?
Darwin saw many examples of one species eventually becoming another — for example, the thirteen species of finches. They obviously were of the same parent population and yet they were distinct in a way that was arguably adaptive.
There are also several different species of iguanas (land and marine) and prickly pears found on different islands.
9. How did the animals get to the different islands?
Ocean passengers (reptiles aboard rafts of tangled vegetation).
No amphibians or land mammals with the exception of rats aboard ships.
Some animals could cross the ocean on their own power (examples: fish, sea turtles, penguins, and marine
mammals — the sea lions, fur seals, and dolphins).
Sea birds and shore birds had the ability to arrive by air. Land birds would either have to get caught up in a gustand be borne along by an exceptionally strong tail wind or perched on a branch in a tree hollow.

38© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

KEY10. Is the water safe? Clean? Drinkable?
Don’t drink the water unless it is bottled. It is not safe to drink.

KEY

11. What is the elevation of the islands?
The highest elevation occurs on Santiago Island: 900 meters above sea level.
12. What is the human population?
Four of the islands have human settlements. The total human population in the Galapagos is 18,000.
13. Would inhabitants need weapons?
No weapons will be needed. The animals are not aggressive for the most part.
14. What is the weather like?
(Refer back to question #4) “Except during one short season, very little rain falls, and even then it is irregular;
but the clouds generally hang low. Hence, whilst the lower parts of the islands are very sterile, the upper parts,
at a height of a thousand feet and upwards, possess a damp climate and a tolerable luxuriant vegetation. Thisis especially the case on the windward sides of the islands, which receive the moisture from the atmosphere....”(Charles Darwin, Voyage of the Beagle, 1839)
15. What did Charles Darwin find interesting about the Galapagos?
Darwin found the Galapagos to be a “living laboratory” for observing evolution.
16. What do currents have to do with the dry climate? Why isn’t it hot?
(Refer back to question #4) Considering that these islands are placed directly under the equator, the climate is
far from being excessively hot; this seems chiefly caused by the singularly low temperature of the surrounding
water, brought here by the southern Polar current. (Charles Darwin, Voyage of the Beagle, 1839)
One of the keys to understanding the Galapagos is the climate. The islands are isolated (by several hundred
miles of ocean), so the climate is determined by the ocean currents, which in turn are influenced by the tradewinds which push the currents. The Galapagos are at a major intersection of several currents, which vary inintensity during the year as their diving trade winds blow and then weaken in a cycle that gives two distinct
seasons to the island.
17. Why hasn’t the wildlife evolved past birds and reptiles?
Mammals are generally not suited to the rigors of the long ocean voyage to the archipelago. Although understandable, it is still amazing to note that there are only seven species of mammals that are indigenous to the
Galapagos. It is even more amazing that, of these, there are only three land mammal species — all rats! The balance of this under-represented class were either carried through the air by storm-force winds (two bat species)
or by long-distance swimming (the sea lions and fur seals).
18. What is the volcanic life?
Pioneers after volcanic activity include bacteria, algae, and fungi, which provide the beginnings of an organic
base for higher forms of life.
19. What types of mineral deposits exist?
Sulfur vents, pockets of magna, pit crates, molten rocks
20. What is the impact of human involvement on the Galapagos?
The influence of humans has brought several wild species to the point of extinction. These include the giant
tortoise, sperm whale, and the fur seal.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

39

EXPLORATION ACTIVITY: GO FISH
MATERIALS NEEDED• 1 clear and 1 gray 8½” x 11” acetate sheet (seePre-lab Materials for ordering information)• Bandanas for each student (from Engagement activity)• Go Fish handout for each student (with frequency datatable)• 1 Go Fish tally sheet

INSTRUCTIONS FOR TEACHERS• In the activity, students will pretend to be predatory
animals whose favorite food is “acetate animals.”• To prepare the “food,” cut the gray and clear acetate
sheets into squares. You will need 200 squares of grayand 200 squares of clear. (Other colors may be substituted depending on the coloration and type of flooring.)• In the adjacent lab room (which represents the habitat
for the fish population), place all the squares randomlyon the floor, equally distributing the gray and clear
squares. Make sure the lights are off or dimmed sowhen the students enter they do not notice the squareson the floor prior to the beginning of the activity.
• Each student has received a bandana for the Galapagos“trip” and will use this bandana as a blindfold. After
students have been blindfolded, they need to be led into
the adjacent room. Depending on the size of the classand the size of the other room, the students may need
to be taken into the room in small groups. Position thestudents around the room so that each student has anindividual area, or “niche,” in which to “fish.”40• Once the students are in place, have them remove
their blindfolds, turn on the light (which represents thedaylight in which they search for food), and instruct thestudents to gather as many pieces of acetate as possible
within 10 seconds. After 10 seconds, dim the lightagain and instruct the students that the “sun has gonedown” and they can no longer search for food.
• The students will then return to the classroom and countthe color of each acetate animal they captured and thensubtract that amount from the number of organisms before selection. Record the data for each individual student
on the tally sheet. You can have students come forward
to record their data or take the data orally and record it.
You may choose to put the tally sheet on an overhead forconvenience. Total the data for the entire class on the tally
sheet and have students record the data in the frequency
data tables on their handouts. This information will be
used to complete the rest of the table to determine thefrequency of the trait after the first selection and to answer
the questions that follow. (You will need to provide to
students the number of organisms before selection.)• Point out to the students that they will determine thenumber of organisms left after the first selection. Also
discuss with your students the variations in predator
strategy used by the students, such as selective (picking up pieces individually) or nonselective (scooping
up all the pieces possible). Repeat the activity in order
to compare the results from no prior knowledge of the“feeding” (1st selection) to an understanding of the“fishing” objective (2nd selection).

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

TALLY SHEET — GO FISH
Record the data for the individual students on the tally sheet. Then use this information to fill in the frequency data table.

Student

Results after first selection# Smoky# ClearResults after second selection
Student# Smoky# Clear

Total

1.

1.

2.

2.

3.

3.

4.

4.

5.

5.

6.

6.

7.

7.

8.

8.

9.

9.

10.

10.

11.

11.

12.

12.

13.

13.

14.

14.

15.

15.

16.

16.

17.

17.

18.

18.

19.

19.

20.

20.

21.

21.

22.

22.

23.

23.

24.

24.

Total

Total

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

Total

Final total

41

EXPLORATION ACTIVITY: GO FISH
INSTRUCTIONS FOR STUDENTS
You will be blindfolded and led into an adjacent lab room, which is the habitat for a population of acetate “animals.”
These animals are all the same species. The variations in color of these animals are due to genetic inheritance. The
allele for smoky (gray) is dominant over the recessive allele for clear (no coloration) in these animals.
You are a predator and your favorite food is acetate “animals.” You will have a limited period of daylight to searchfor your prey, so catch as many as you can before the sun goes down. After sundown, you and the other predators inyour class will determine the number of each type of animal left after selection.
Directions: First, count each color of the acetate “animals” you selected and then subtract that number from the total
number of organisms before selection (200) for each color. Record all the data for each student on the tally sheet.
Using the totals for the entire class from the tally sheet, record the data in the table below and complete the rest of
the table using the formulas to determine the frequency of the trait after the first selection. Repeat the process for asecond selection and compare your results.
Remember that evolution is defined as a change in the gene frequency over a period of time.
Formula to keep in mind:
p+q =1
p = Frequency of smoky organisms
q = Frequency of clear organisms

FREQUENCY DATA TABLE
Color

Number oforganisms
before selection

Frequencyof trait
before selection

Number oforganisms left
after the
1st selection

Frequency of
trait after
1st selection

Number oforganisms left
after the2nd selection

Frequency of
trait after
2nd selection

Smoky (gray) p

Clear qTotal
*To find the frequency of each trait, divide the total number for each column into the number of smoky or clear inthat column. Answers will vary depending on the number of organisms left after each selection.
1. What happened to the frequency of the smoky color? Why?
2. What happened to the frequency of the clear color? Why?
3. Which color of acetate “animal” had the advantage?
4. How would Darwin explain the results of this activity?
5. What type of predator strategy did you use in the activity for the first selection?
6. How did your strategy change with a second selection?
7. Define evolution in your own words.

42© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

EXPLORATION ACTIVITY: GO FISH

KEY

Color

Number oforganisms
before selection

Frequencyof trait
before selection

Number oforganisms left
after the
1st selection

Frequency of
trait after
1st selection

Number oforganisms left
after the2nd selection

Smoky (gray) p

200

0.5

varies# of smoky
left/total left=svariesClear q200

0.5varies# of clear left/
total left = cvaries

Total

400

1

variess+c=1variesFrequency of
trait after
2nd selection
Sameformula as
first selection
Sameformula as
first selection
Sameformula as
first selection*To find the frequency of each trait, divide the total number for each column into the number of smoky or clear inthat column. Answers will vary depending on the number of organisms left after each selection.
1. What happened to the frequency of the smoky color? Why?
Decreased. Because the smoky-colored pieces of acetate were easier to see and therefore “catch” (if the floor
tile is light colored), so there were fewer smoky animals left after the selection.
2. What happened to the frequency of the clear color? Why?
Increased. Because the clear acetate pieces were more difficult to see (if on a light-colored floor tile), there weremore clear animals left after the selection.
3. Which color of acetate “animal” had the advantage?
The clear color had the advantage because they were more difficult to see on a light-colored floor and, therefore,
they blended into the surroundings.
4. How would Darwin explain the results of this activity?
Variation and natural selection.
5. What type of predator strategy did you use in the activity for the first selection?
Student answers will vary, depending on whether they picked up the pieces of acetate individually (selective
predator strategy) or whether they simply scooped up the pieces (nonselective predator strategy).
6. How did your strategy change with a second selection?
Student answers will vary.
7. Define evolution in your own words.
(Student answers will vary.) Evolution is defined as a change in the gene frequency over a period of time.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

43

EXPLANATION ACTIVITY
INSTRUCTIONS FOR TEACHERS
Upon completion of the Go Fish activity, theclass will complete the data table together.
Ask each group to present an oral summaryof its findings. Their presentations will
provide a launching pad to present scientificexplanations and terminology. Questions tobe addressed are as follows:

1. Did one color of acetate “animal” have an
advantageous variation?
2. What happened to the frequency of theclear color? Why?
3. How might Darwin have explained thechange in the acetate “animal” population?
4. How would you define evolution?

ELABORATION ACTIVITY
MATERIALS NEEDED• PowerPoint presentation part 2• Discussion questions for teacher reference• (Optional) Discussion question handout foreach student• (Optional) Inexpensive backpack or suitcase• 1 set “Family Figures”• Assorted items to pull from backpack (possible examples include picture of young
Darwin, trip journal, family figures forfamily trip, images or models of mentioned
animals)

INSTRUCTIONS FOR TEACHERS
All travelers return home from a trip withmemorabilia of their journey, from photographs and journals to souvenirs and theinformation they learned during their visit. As
students look back on their trip (the information from travel packet materials, their “tripjournal” in the form of the completed groupreport sheet, and information from the Elaboration activity presentation) they will pull out
many examples of lessons learned on their
expedition.

before beginning so that students can write
responses as you go or use the questions verbally as prompts.) In keeping with the themeof unpacking from a trip, you may wish topack a small backpack with some materials topull out at key moments that will facilitate theclass discussion. Depending on the item, you
may find it useful to pass around the room orpost on a wall or black/white board. Examples
are provided with the Discussion Questions
but use your imagination for additional possibilities.
Some of the concepts to be discussed are as
follows:

Darwin’s Theories of Evolution• Descent with modification (Examples: marine
iguana, once a land dweller; flightless cormorant)• Natural selection○ Survival of the fittest/ adaptations,fitness/ extinction○ Can occur quickly (peppered moth, coatcolor of mice, multi-drug resistant TB)

During this elaboration phase, you will help
students sift through their trip “memorabilia.”
In the class discussion that ensues, they will
have the opportunity to correctly use technicalvocabulary and apply scientific reasoning.
Use the second part of the PowerPoint presentation on the module CD to guide the discussion along (you may also print overheads orcopies of the slides to distribute if a presentation is not feasible). Refer to the Discussion Questions for Elaboration for prompts
to ensure student involvement. (You may
distribute copies of the Discussion Questions

44© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

What Causes Natural Selection• Variations; sources of variation; reproductive potential; limited resources• Struggle for resources

Speciation• Adaptive radiation examples: finches, giant
tortoises, prickly pear
• Geographical barrier
examples: Kaibab and Abert Squirrels• Genetic drift• Isolating mechanisms—behavioral (example: boobies); habitat; temporal; mechanical

Biochemical Similarities• Chimpanzees and humans have 2% difference in their DNA sequence• In primates, DNA sequences change about
1% every 3 million years

Similarities in Body Structure• Homologous (different function/samestructure — common ancestor) and analogous
structures (same function/different structure— different ancestor)

The flow of genetic information in the cell
Evidences of Evolution• Paleontology, biogeography, embryology,
comparative anatomy, molecular biology

Relatedness vs. common ancestor• Example: the family figures

DNA (Transcription)↓
mRNA (Translation) tRNA↓
Protein↓Trait© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

45

DISCUSSION QUESTIONS FOR ELABORATION
1. Explain what is meant by Darwin’s Theory of Descent with Modification.
• Give examples• What are the implications of Darwin’s theory of natural selection?
• Can you think of examples that illustrate this theory?
• What did Darwin mean when he described certain organisms as being more fit?
• What kinds of evidence did Darwin use to support his theory?
2. What causes natural selection? Give examples of adaptations.
3. What does natural selection equal?
4. Give examples of findings by other biologists that support Darwin’s hypothesis.
5. What causes speciation? Give examples.
6. Discuss the evolution of Darwin’s finches.
7. What kinds of evidences support evolution?
8. What are homologous structures, analogous structures, and vestigial organs? Provide examples and discuss therelevance of each to evolution.
9. How can two species that look very different from one another be closely related?
10. Distinguish between related and descended.
11. How is DNA used to show evolutionary similarities in species?

46© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

DISCUSSION QUESTIONS FOR ELABORATION
1. (Pull a picture of young Darwin from the backpack or refer to slide 28. This reminds students of Darwin’s theories
of evolution.)
Explain what is meant by Darwin’s Theory of Descent with Modification. (slide 29)
New species are modified descendents of older species.
• Give examples
Marine iguanas, giant tortoise, flightless cormorants, finches.
• What are the implications of Darwin’s theory of natural selection?
Those best adapted to the environment will survive and reproduce.
• Can you think of examples that illustrate this theory?
Finches, marine iguanas, prickly pears.
• What did Darwin mean when he described certain organisms as being more fit?
Fit organisms are those that are better suited to survive in their environment and pass on their traits to the next
generation.
• What kinds of evidence did Darwin use to support his theory?
Darwin used observations of species and the fact that the earth has changed over time. He also argued that fossil
records, the geographical distribution of species, homologous structures of living species, and similarities inearly development, provided evidence for his theories.
2. (Pull from the backpack a well-worn trip journal. Read a “journal entry” about what causes natural selection;for example: “From my observations, it seems to me that four main factors influence or cause this phenomenon ofnatural selection.”)• What causes natural selection? (slide 30)• There are variations among individuals within a population that are inherited.
• Populations possess enormous reproductive potential.
• Resources are limited.
• There is a struggle for resources; only the fit individuals survive.
• Give examples of adaptations.
Adaptations are inherited characteristics that increase an organism’s chance of survival. Example-Variations in
the beaks and feet of the finches.
3. What does natural selection equal? (slide 31)
Natural selection = Populations + Environment
Populations exhibit variations and possess enormous reproductive potential.
The environment has limited resources and there is competition for these resources.
4. Give examples of findings by other biologists that support Darwin’s hypothesis.
• Natural selection in the peppered moth before and during the industrial revolution. (slide 32 or figure 1)• Experiment conducted at the University of Michigan studying barn owls’ success at catching buff-colored
mice and gray mice on differing colors of soil. (slide 33 or figure 1)• Antibiotic resistant bacteria.
5. What causes speciation? Give examples. (slide 34)
Isolating Mechanisms (slides 35-36 or figure 2)• Behavioral Isolation — two populations are capable of interbreeding but have different courtship rituals
or other strategies that involve behavior. Example: boobies.
• Geographical Isolation — two populations separated by geographical barriers. Example: Kaibab andAbert Squirrels. (slide 37 or figure 2)• Temporal Isolation — two species reproduce at different times. Example: boobies; three different but
similar species of orchids.
• Mechanical Isolation — occurs when male and female genitalia are structurally incompatible. Example:
flower structures select for different pollinators.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

47

KEY

Adaptive Radiation — process by which a single species or small group of species evolves into several different forms that live in different ways. (slide 38 or figure 3)
Genetic Drift — in a small population, individuals that carry a particular allele may leave more descendants
than other individuals, simply by chance. Over time, this allele may become more prevalent in the population.
6. Discuss the evolution of Darwin’s finches. (slides 38-39 or figure 3)
Speciation in the finches occurred by a new population which became geographically isolated; this resulted inchanges in the new population’s gene pool, reproductive isolation, and competition for resources.
7. What kinds of evidences support evolution? (slide 40)• Paleontology — study of fossils reveals the prehistoric existence of extinct species.
• Biogeography — study of the distribution of organisms; similar selection pressures, different animals end up
evolving certain features in common.
• Embryology — similar stages in development (ontogeny) among related species helps establish evolutionary
relationships (phylogeny).
• Comparative anatomy — describes two kinds of structures that contribute to the identification of evolutionary
relationships among species (homologous structures, analogous structures).
• Molecular biology — examines the amino acid sequences of DNA and proteins to determine evolutionary.
relationships between species; even small changes in nucleotides can tell us how organisms are related.
8. What are homologous structures, analogous structures, and vestigial organs? Provide examples and discuss therelevance of each to evolution. (slide 41)
Homologous Structures — structures that have different mature forms but develop from the same embryonictissue; provide strong evidence for common ancestry.
Example: forelimbs of vertebrates.
Analogous Structures — structures that have similar functions but different origins; do not indicate common
ancestry.
Example: wings of a bird and wings of an insect.
Vestigial Structures — organs that show no useful function in and organism provide strong evidence for common ancestry; suggest that an organism’s ancestor once used that organ.
Example: miniature legs, tails, or other structures.
9. How can two species that look very different from one another be closely related?
Two species are closely related if they share a common ancestry. If one species experiences natural selection ina particular kind of environment, such as an aquatic environment, it may look different from its related species
in a different environment. Example: marine iguana and the land iguana.
10. Distinguish between related and descended. (figure 4, figure 5 or slide 42, and family figures. Cut out the imagesof the eight family members found in the notebook or on the module CD. For added durability, laminate each figure
or mount it on foam board. Use figure 4: How Did We Evolve, as a guide to place each figure on the wall, black orwhite board as you describe how this family member relates to the others.) NOTE: Students often make the mistakeof thinking that humans are descended from apes. After the family tree exercise, figure 5 or slide 42 can help to demonstrate humans’ and apes’ descent from a common ancestor.
Use the example of the family tree.
11. How is DNA used to show evolutionary similarities in species? (slide 43, figure 5 or slide 42)
DNA is passed directly from common ancestors to their descendants and controls development of traits.
Primate DNA sequencing changes about 1% every three million years. By looking at protein sequences we cantell that humans and chimpanzees have a DNA sequence that is 98% identical; thus we can tell that humans andchimpanzees shared a common ancestor until between five and six million years ago.

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© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

FIGURE 1: PEPPERED MOTHS — A CASE OF RAPID NATURAL SELECTION
The peppered moth is a famous example of evolution through natural selection. Before the industrial revolution, the common variety of this moth waswhite with black speckles (called typica), which serves as a good camouflage on lichen-covered tree barks. Starting around 1850, scientists began tonotice a dark morph of the peppered moth (called carbonaria) and a range of intermediately shaded variant (insularia). Over the next 50 years, the darkvariety gradually became the most prevalent in regions downwind from large industrial centers, where soot and other air pollutants from factories
darkened the bark of trees and killed most lichens.
In 1896, amateur moth collector J. W. Tutt proposed that the dark morph of the moth might be better camouflaged on polluted surfaces than the whitemorph, making it more difficult for birds to prey on the dark moths and therefore leading to an increase in the frequency of carbonaria — a case ofnatural selection. Subsequent studies, most notably one by Bernard Kettlewell starting in 1953, provided hard evidence to support this theory.

Before the industrial
revolution, the light (typica)
peppered moth had a better
camouflage than the dark
(carbonaria) variety and was
the more common variety.

Coal burning during theindustrial revolution darkened
the bark of trees and killed
the lichens, making the light
moth more easily detectableto predators. The result wasthat the dark moths survived
predation more frequently
and became the more common variety.

ANOTHER EXAMPLE
A biologist at the University of Michigan
conducted an experiment in which hereleased buff-colored mice and gray mice
into an enclosed room with barn owls. The
floor alternated between buff-colored soil
and gray soil each day and had an ample
supply of sticks for the mice to hide under.
Each day, four mice of each color were released for 15 minutes. In 44 trials with eachsoil type, almost twice as many of the more
visible color of mice were caught by the owls.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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FIGURE 2: SPECIATION
A model of how two populations of a species may become isolated and evolve to produce two species.

1.

2.

genes

1 population

1 species

1 species

A species made up of one interbreeding population.

In time, the species may expand its range and divide into two or more
populations that have little gene exchange.

3.

4.
BARRIER2 subspecies

BARRIER

1 species

If a barrier to interbreeding arises, the gene pools become isolated. Overa very long period of time, the different populations become geneticallydistinct subspecies through mutation and selection.

The populations may be considered separate species when they become
so different that they can no longer interbreed even though little or no
physical barrier remains.

SPECIATION IN ACTION

SPECIATION MAY BE A GRADUAL PROCESSGENETIC DISTANCEThe Kaibab (left) and Abert (right) squirrels are related. When they
became geographically isolated on opposite rims of the Grand Canyon,
they began to develop differences.

Daughter
species A
0
Daughter
species B

Interbreeding
population(parent species)
TIME

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© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

FIGURE 3: EVOLUTION AMONG GALAPAGOS FINCHES© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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FIGURE 4: DESCENDED OR RELATED?
To better understand the difference between being descended or related, let us consider my own family.
Put Scotch tape or glue-on magnetic strips on the back of each picture to attach the family figures to the white/chalk board when you introduce them.

This is me.

These are my parents (Wilber andMaurine). I am related to and havedescended from my parents.

This is my mother’s sister, Aunt Gertrude, andher husband, Uncle Waldo. I am related to
Aunt Gertrude but I did not descend from her.

These are my maternal
grandparents (Grandpa
Willie and Grandma Myrtle).
Both my cousin Kelly andI share common ancestors
and are descendents of ourmaternal grandparents.

52

This is my cousin Kelly. I am
related to Kelly (first cousins)
and to my Aunt Gertrude, but
I did not descend from them.

Related to anddescended fromRelated to but
not descended
from© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

ME© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

KELLY© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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WILBER© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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MAURINE© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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GERTRUDE© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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WILLIE© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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FIGURE 5: PRIMATE EVOLUTION

GibbonOrangutan

GorillaBonoboChimpanzee

Human

0

2
Humans shared acommon ancestor
with chimpanzees
and bonobos until
about 5 million
years ago.

6

8

MILLIONS OF YEARS AGO

4The ancestorof orangutans
diverged about
8 million years
ago. The ancestors of gibbons
diverged from theother apes earlier,about 10 million
years ago.

About 7 million years ago, thegorilla’s ancestor diverged fromthe ancestor of chimpanzees,
bonobos, and humans.

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EVALUATION ACTIVITY
INSTRUCTIONS FOR TEACHERS
Assemble enough “treasure chests” for the class to have one treasure chest per pair of students (see Pre-lab Materials
list for ordering instructions or use small boxes or envelopes). Photocopy the treasure answer strips below or print
them from the module CD; make enough copies to place one set of strips in each chest. Cut out each answer, resulting in eight strips of paper per set. Place all eight strips into each treasure chest.
Have the students work in pairs. Give each pair an Evaluation Activity handout and a treasure chest containing acomplete set of eight answer strips. (If you are not using the treasure chests, you can simply give a photocopy of theanswers sheet to students and have them cut out each strip). Ask them to answer each question by matching it to theappropriate answer strip. Students can paste down strips and turn in for grade. After the class has finished, review
the responses with the class.

Sexual recombination and mutations.
New species are modified descendents of older species (examples found on the Galapagos include the marine
iguana, once a land dweller, and the flightless cormorant).
Kaibab and Albert squirrels in the Grand Cannon; the different dances performed by the boobies.
Adaptive radiation and isolating mechanisms.
Survival of light- vs. dark-colored peppered moth; survival of buff-colored vs. gray mice; antibiotic resistantbacteria.
Darwin’s finches, land and marine iguanas, different species of prickly pears.
Those organisms best adapted to the environment will survive, reproduce, and pass on their traits to the next
generation.
Paleontology, biogeography, embryology, comparative anatomy, and molecular biology.

70© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

Name _______________________

Date __________________EVALUATION ACTIVITY
Complete the following questions using the strips from the treasure chest:
1. Explain what Darwin meant by his theory of descent with modification.

2. Explain the meaning of modification by natural selection.

3. Name some experiments that have demonstrated evolution by natural selection.

4. What are the sources of variation that lead to evolution?

5. Evidences for evolution come from the following:

6. What processes can result in speciation?

7. Isolating mechanisms which prevent mating include behavioral, habitat, temporal, mechanical, and geographicalbarriers. What are examples of behavioral and geographical isolation?

8. Give examples of adaptive radiation found on the Galapagos.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

71Name _______________________

Date __________________KEY

EVALUATION ACTIVITY
Complete the following questions using the strips from the treasure chest:
1. Explain what Darwin meant by his theory of descent with modification.
New species are modified descendents of older species (examples found on the Galapagos include the marine
iguana, once a land dweller, and the flightless cormorant).
2. Explain the meaning of modification by natural selection.
Those organisms best adapted to the environment will survive, reproduce, and pass on their traits to the next
generation.
3. Name some experiments that have demonstrated evolution by natural selection.
Survival of light- vs. dark-colored peppered moth; survival of buff-colored vs. gray mice; antibiotic resistantbacteria.
4. What are the sources of variation that lead to evolution?
Sexual recombination and mutations.
5. Evidences for evolution come from the following:
Paleontology, biogeography, embryology, comparative anatomy, and molecular biology.
6. What processes can result in speciation?
Adaptive radiation and isolating mechanisms.
7. Isolating mechanisms which prevent mating include behavioral, habitat, temporal, mechanical, and geographicalbarriers. What are examples of behavioral and geographical isolation?
Kaibab and Albert squirrels in the Grand Cannon; the different dances performed by the boobies.
8. Give examples of adaptive radiation found on the Galapagos.
Darwin’s finches, land and marine iguanas, different species of prickly pears.

72© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

FROM FINCHES TO FISHES IMPLEMENTATION PLAN — WET-LAB
Activity

Estimated
Time

Engagement Activities:
Fishy Family Tree Activity

Materials/Equipment
Fish with scales handout
Fishy Family Tree handout

20 minutes

Protein Electrophoresis
Role PlayThree cards representing three different proteins

Practice Loading Wells
60 minutes

Essential Question:

Rocking Platform (optional)

How are protein “fingerprints” used
to determine the evolutionary relationships among different species?

Staining Tray
1 hour staining
Staining and
Destaining of gel

Overnight
destaining

Objectives:

Water

Equipment for vertical gel electrophoresis

Run GelTo compare proteins from fivedifferent fish species to determine
evolutionary relatedness.

Bio-SafeTM Coomassie stain

p20 Micropipettes

Load Fish Samples

Purpose:• To describe the structure andfunction of proteins in relation to gelelectrophoresis• To identify proteins present in eachof five samples extracted from fishusing gel electrophoresis• To interpret the results of gel
electrophoresis• To make inferences about therelatedness of fish species basedon the similarities of their protein“fingerprints”• To describe the process of protein
electrophoresis

Comparative Proteomics Kit I: Protein
Profiler module (Bio-Rad Kit #1662700EDU)

Wet-lab Activity

Purpose/Objectives/
Essential Question

Alignment with NC Competency Goals
Biology
Goal 1
Objectives 1.01, 1.02, 1.03, 1.04, 1.05
Goal 2
Objectives 2.01, 2.02, 2.03

Goal 3
Objectives 3.01, 3.04, 3.05
Goal 4
Objectives 4.01, 4.02, 4.03

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

73WET-LAB ENGAGEMENT: A FISHY FAMILY TREE74

MATERIALS NEEDEDTEACHER INSTRUCTIONS• Six color printouts of fish and scales (available on module CD) — one for each student
group (you may wish to place these in plastic
sheet protectors or laminate for added durability)• One Fishy Family Tree handout for each
student (copied from notebook or printed
from module CD)• PowerPoint presentation part 3 (slide 46) oroverhead of figure 7 from module notebook
or CD

Divide the class into six groups and provide
each group with a Fish with Scales handout.
Distribute a Fishy Family Tree handout toeach student. Have each group examine theimages of the fish and their scales and work
together to fill out the data charts on theirindividual handouts. Each student should
then answer questions 1-3 individually. When
students have finished, review the fish evolutionary tree (slide 46 of PowerPoint presentation part 3 or figure 7).

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

A FISHY FAMILY TREE
We know that catfish, tuna, and swordfish are all fish and that all three share an ancestor. But which two of thesefish share a more recent ancestor? In other words, which two of these fish are most closely related?
To find out, examine the illustrations of these three fish and of their scales. Then fill out the data chart below.

Kind of Fish

Tail Fin Shape(fan shaped vs. lobed)

Presence of Barbels(“whiskers” present
vs. absent)

Scale Type(cycloid, ctenoid, etc.)

CatfishTuna
Swordfish

1. Which two fish do you think are most closely related?

2. Please explain your reasoning.

3. Label the evolutionary tree below to show your hypothesis.
(Write the name of one kind of fish in each of the three boxes.)© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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FIGURE 6: FISH WITH SCALES

Channel catfish
Ictalurus albidus

Scaleless

Bluefin tuna
Thunnus thynnus
Ctenoid scales
Have a toothed edge

Swordfish
Xiphias gladius

Ctenoid scales
Have a toothed edge
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© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

A FISHY FAMILY TREEKEY

We know that catfish, tuna, and swordfish are all fish and that all three share an ancestor. But which two of thesefish share a more recent ancestor? In other words, which two of these fish are most closely related?
To find out, examine the illustrations of these three fish and of their scales. Then fill out the data chart below.

Kind of Fish

Tail Fin Shape(fan shaped vs. lobed)

Presence of Barbels(“whiskers” present
vs. absent)

Scale Type(cycloid, ctenoid, etc.)

CatfishLobed

Present

Scaleless

Tuna

Fan shaped

AbsentCtenoid

Swordfish

Fan shaped

AbsentCtenoid

1. Which two fish do you think are most closely related?
Tuna and swordfish.
2. Please explain your reasoning.
Similar traits.
3. Label the evolutionary tree below to show your hypothesis.
(Write the name of one kind of fish in each of the three boxes.)

CatfishTuna

Swordfish© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

77Catfish

Cod
Hake
Pollock

SalmonTrout

Carp
Minnow
Pike

Swordfish
Tuna
MackerelSmelt
Snapper
Perch
WalleyeBass

FlounderSole
Halibut

Anchovy
Herring
SardineGar

Sturgeon

Shark
Chondrichtthyes
Ostheichtthyes
AgnathaAmphibia

Reptilia Aves

Mammalia

Lamprey

FIGURE 7: FISH EVOLUTIONARY TREE
Different branches of related organisms separated at different evolutionary times. The further
apart species are on the tree, the less related they are. Mollusks and arthropods diverged
from one another before the emergence of chordates (animals with backbones) very early inevolutionary time. These animals are only distantly related to fish, birds, reptiles, mammals,
and amphibians, which are more closely related to each other.

Mollusk

Echinoderm

Arthropod

Fish illustrations from the National Oceanic and Atmospheric Administration/Department of Commerce

Metazoa

78© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

BACKGROUND FOR THE WET-LAB
Proteins account for more than 50% of thedry weight of most cells, and they are instrumental in almost everything cells do. Proteins are used for structural support, storage,transport of substances, signaling from onepart of the organism to another, and movement and defense against foreign substances.
In addition, as enzymes, proteins selectively
accelerate chemical reactions in cells.

KEY
CONCEPT
Gel electrophoresis is a groupof techniques
used to separate
molecules basedon physical characteristics suchas size, shape, or
isoelectric point.

In gel electrophoresis, separation of charged
molecules is achieved by subjecting thecharged molecules to an electric current thatforces them to migrate through a matrix (thegel). The two types of gel matrices used inmolecular biology applications are agaroseand polyacrylamide. Agarose is commonlyused to separate large fragments of DNA.
Polyacrylamide has a greater resolving power
and is commonly used for separating proteins.
The behavior of molecules during gel electrophoresis depends on their size, shape, and net
charge. Linear DNA molecules have uniformly negatively charged backbones and a shapethat normally varies only in its length, so that
migration is directly dependent on the size of
the DNA fragment. With proteins, the story
is different. The net charge of a protein isdependent on its amino acid content; proteinscan carry a positive net charge, negative net
charge, or they may be neutral. Similarly, theshapes of proteins vary widely. Furthermore,a protein may consist of several polypeptide
sub-units held together by hydrogen bonds,
hydrophobic interactions, and/or disulfide
bridges. Therefore if proteins in their native
configurations are electrophoresed, they
will not all necessarily migrate in the same
direction, and the distances migrated will not
be solely a function of their sizes. Thus gel
electrophoresis of native proteins cannot
be used to determine molecular weights ofproteins, but it can provide other information
on characteristics of the protein in a mixture.

sample mixture is treated with hot SDS, thisdisrupts all the hydrogen bonds maintaining
the protein’s three-dimensional shape. If
the sample is simultaneously treated with areducing agent, such as beta-mercaptoethanol, disulfide bridges will also be broken,
leaving the protein a linear chain of aminoacids. The SDS binds to the protein backbone without regard to amino aid sequences,
imparting a uniform negative charge to themolecules. Under these conditions, all theproteins in a mixture assume the same shapeand charge. During electrophoresis, theymigrate toward the positive pole at a rate
proportional to the log 10 of their molecularweights.
Gel electrophoresis of proteins does notprovide any direct information about aminoacid sequences, and so cannot be used in a
precise way to reconstruct evolutionary
history. The overall protein fingerprints
obtained from different species are moresimilar when closely related species arecompared. The evolution of different groupsof fish and the varying degrees to which they
are related are a topic of ongoing study.

To make protein migration rates a function ofmolecular weight, it is necessary to impose a
uniform shape and charge on all proteins ina mixture. This goal can be largely achievedby treating the protein mixture with thedetergent sodium dodecyl sulfate (SDS). If a

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

79WET-LAB ENGAGEMENTENGAGETo demonstrate the concept of protein electrophoresis, have three students come to the frontof the room. Present each student with one of the three cards following this section (also on
the module CD). Each card represents a protein molecule with a different molecular weight.
Have students move as their proteins would move through the polyacrylamide gel based on theirmolecular weight. The smaller the mass of the protein molecule, the farther it moves towards the
opposite end of the gel.
Three protein cards:
Protein
1. Myosin (H-chain)
2. Ovalbumin
3. β-lactoglobulin

Molecular weight, Dalton, D
200,000
43,00018,400 (smaller mass moves farther toward the positive end)Three factors affect the movement of molecules through a gel during electrophoresis:• The size of protein molecules: The smaller the protein, the farther down the polyacrylamide gel itwill move. The size of a protein molecule is expressed by its molecular weight (in Daltons). Most
proteins have masses on the order of thousands of daltons, so we measure them in kilodaltons (kD).
• Charge density of the protein: A ratio of a protein’s electrical charge and mass. Charge density
affects a protein’s mobility through a gel during electrophoresis. Since each protein is made ofa unique combination of amino acids, each of which may have a positive, negative, or neutral
charge, the net charge of each protein is naturally different.
• Protein structure: Secondary, tertiary (which result from protein folding), and quaternary structure must be disrupted to separate proteins by size. The combination of heat and the detergent
SDS denatures the protein’s structure. The intrinsic charges of proteins are obscured by placing
a strong anionic detergent SDA in both the sample buffer and the gel-running buffer. SDS binds
to and coats the proteins and keeps them as denatured linear chains (see Figure 8). In this form,
proteins migrate in polyacrylamide gels as if they have equivalent negative charge densities, andmass becomes the only variable affecting the migration rate of the protein. This technique iscalled SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis).

FIGURE 8: Sodium Dodecyl Sulfate- -------------------

The combination of heat and SDS detergent denaturesproteins for SDS-PAGE analysis.

---------------------HEAT & SDS

Discussion Questions:
What is a protein?
Proteins are charged molecules; one of the complex organic chemical compounds that form
the basis of living tissues; consist of long chains of amino acids connected by peptide bonds
to form one or more polypeptides. Examples are enzymes, hemoglobin, and antibodies.
How do proteins function in organisms?
Proteins determine how an organism functions, what it eats, how it looks, and where it
lives. Proteins form the basis of living tissues and carry out the thousands of chemical
reactions necessary to maintain life.
Do humans and fish have the same proteins?
Actin and Myosin make up the structure and function of muscle found in all animals.

80© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

WET-LAB EXPLORATIONEXPLORE(Depending on class time and ability, you may prepare samples in advance or guide students
through the preparation.) Before entering the lab, review safety procedures. Give each student
a copy of the lab procedure quick guide. Remind them to keep accurate records. In the lab, students will use the technique of protein electrophoresis to discover the relatedness of five typesof fish. Using demonstration equipment, briefly describe the process used in the lab.
The purpose of the gel is to act as a medium to slow the rate of movement of the protein molecules, and to provide a lane for each sample to move in a straight line, much like a track. The
sample loading buffer contains SDS and dithiothreitol (DTT), which will disrupt all the hydrogenbonds and disulfide bridges leaving the proteins linear with an overall uniform negative charge.
Add samples of fish proteins to designated wells.
Close the lid of the electrophoresis chamber and turn on the electricity.
After 30 minutes, remove the gel from the electrophoresis chamber and place it in a weigh boat
for staining. (10 minutes)
Return the stain to the original container.
Flood the gel with destain solution and let it sit overnight until the bands are clearly visible.

WET-LAB EXPLANATION
. ...
...
... ...
....
..... ....
..........
....
. ....
..
..... ...
... ...
....

. .... ..

EXPLAIN

After the electrophoresis process, students will analyze the gels. The protein profile for each fish
will vary. To facilitate discussion, choose a representative gel. Place the results on an overhead
projector. Highlight the bands with a marker. Some sample questions for discussion are as follows:
How would you identify the five proteins based on their movement through the gel?
Protein
1. Myosin (H-chain)
2. Bovine serum albumin
3. Ovalbumin
4. Carbonic anhydrase
5. β-lactoglobulin

Molecular weight, Dalton, D
200,000 (largest mass travels least)
68,00043,00029,00018,400 (smallest mass travels farthest)

Which fish seem to have similar protein profiles? How many proteins do they have in common?
Which fish do not have similar protein profiles? What does this tell you about the relatedness ofthe fish?

WET-LAB EVALUATIONEVALUATE

Based upon their findings, ask students to place the names of the five fish on a hypotheticalevolutionary tree. Lead a discussion with the class regarding their decisions for placement offish on the hypothetical evolutionary tree. Remind students that gel electrophoresis of proteins
does not provide any direct information about amino acid sequences, and so cannot be used inany precise way to reconstruct evolutionary history. The evolution of different groups of fish
and the varying degrees to which they are related are topics of ongoing study.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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Myosin
200,000 D© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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Ovalbumin
43,000 D© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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β-lactoglobulin
18,400 D© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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FROM FINCHES TO FISHES WET-LAB:
FISH PROTEIN FINGERPRINTING BY GEL ELECTROPHORESIS• To make inferences about the relatedness offish based on the similarities of their proteinsprofiles.
• To demonstrate the process and concept ofprotein electrophoresis.

PURPOSETo compare proteins from five different fish
to determine phylogenic relationships.

OBJECTIVES• To perform gel electrophoresis to identify
proteins present in each of five samples extracted from fish.
• To interpret the results of electrophoresis.

TEACHER PREPARATION
Obtain fish samples and distilled water—trip
to grocery store.
Set up student and teacher workstations.

Student Workstations
1.5 ml micro test tube

6 each

1.5 ml screw-cap micro test tube

7 eachMicropipettes and tips or disposable pipettes

1 eachFish samples (5 types)

1 gram eachIndelible marking pen, fine point

1

Laemmli sample buffer

1.5 mlKnife or scissors to cut fish samples

1

□
□
□
□
□
□
□

Teacher’s (Common) Workstation
Water bath or hot plate set to 95° C

1Laemmli sample buffer — 30 ml

1

Actin and myosin standards

1 vial□□□Precision Plus Protein Kaleidoscopeprestained standards — 500μl

1 vial□ACTIN AND MYOSIN STANDARD
A control sample containing actin and myosin
proteins is provided in a lyophilized form thatis stable at room temperature. Store these
proteins, along with the Precision Plus Protein
Kaleidoscope standards, in the freezer for longterm safe-keeping. To rehydrate the sample,
add 500 μl of Bio-Rad Laemmli sample buffer

to the vial and incubate it at room temperaturefor five minutes. Transfer the rehydrated actin
and myosin sample to a labeled screw cap tube
using a disposable plastic transfer pipet. Like
the fish protein samples, the actin and myosinsamples must be heated for five minutes at
95°C before loading on gels.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

89LABORATORY DAY 1:
SAMPLE PREPARATION – MUSCLE PROTEIN EXTRACTIONPROCEDURE
1. Label (with indelible pen) 1.5 ml fliptop microtubes with the names of the fishsamples to be analyzed. There should be
one labeled tube for each fish sample being
prepared for electrophoresis.

6. Pour the buffer containing the extracted
proteins, but not the solid fish piece, to alabeled 1.5 ml screwcap tube. Note: It’s notnecessary to transfer all of the fluid to thescrewcap tube, since only a small volume(< 20 μl) is actually needed for gel loading.

2. Add 250 μl of Laemmli sample buffer toeach labeled tube.

7. Obtain aliquots of the Kaleidoscope (KS)and actin and myosin (AM) standards fromyour teacher.

3. For each sample, obtain a piece of fishmuscle (avoid skin, fat, and bones) approximately 0.25 x 0.25 x 0.25 cm3, and transfer itto the appropriately labeled microtube. Closethe lid.

8. Heat the fish samples and the actin andmyosin (AM) sample in their screwcap tubes
for 5 minutes at 95°C to denature the proteinsin preparation for electrophoresis.

4. Gently flick the microtube 15 times withyour finger to agitate the tissue in the sample
buffer.

9. Store the samples at room temperature if
they are to be loaded onto gels within 3-4
hours, or store them at -20°C for up to several
weeks.

5. Incubate the samples for 5 minutes at room
temperature to extract and solubilize theproteins.

90© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

LABORATORY DAY 2: ELECTROPHORESIS
So far you have extracted, denatured, andgiven the proteins from fish muscle tissue anegative charge. Now they can be separated
according to their molecular weights using gelelectrophoresis.
Electrophoresis: gel loading, running, andstaining

PURPOSE OF THIS LABORATORY
Generate profiles for various fish species via
electrophoresis of extracted protein samples.
Procedure Overview:
1. Reheat fish and actin and myosin standard
controls
2. Set up electrophoresis gel boxes
3. Load and run gels
4. Stain gels to visualize protein bands

Laboratory checklist
Student Workstations
Fish protein extracts prepared on laboratory day 1

5 eachProt/Elec pipet tips for gel loading

7 tips□□Mini-PROTEAN® 3 electrophoresis module(gel box — runs one or two gels)

1□

Power supply (200 V constant)1

2-20 μl micropipette

1

Ready Gel precast gel, 15% – 10 wells

1

Sample loading guides – for 10 well comb

1

Thin metal weighing spatula

1

□
□
□
□
□
□

**Actin and myosin standard sample, rehydrated

1 vial□Precision Plus Protein Kaleidoscope prestained standards

1 vial

1X Tris-glycine-SDS (TGS) electrophoresis buffer

As needed

Bio-Safe Coomassie stain for proteinsAs needed

Buffer dam (if running only one gel/box)

Teacher’s (Common) Workstation

Staining trays□□□**You may already have aliquots at student stations© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

91

LABORATORY DAY 2
STEP 1: PREPARE SAMPLES,
ELECTROPHORESIS GELS, AND GEL BOXES
Note: Teachers may have already assembled
the gel boxes. If not, follow these instructions.
1. Reheat frozen samples at 80-95°C for
2-5 minutes to redissolve any precipitateddetergent.
2. Make sure the comb and the tape along thebottom of the Ready Gel cassette have been
removed. If two gels are to be run in one electrophoresis box, place a Ready Gel cassette oneach side of the electrode assembly, with theshort plates facing the inside of the assembly.
If you are running only one gel in the box,
place a Ready Gel cassette on one side of theelectrode assembly and a buffer dam on theother side. Be sure to place the side of thebuffer dam that says “BUFFER DAM”
toward the electrode assembly.
3. Open the gates (cams) on the front of theclamping frame. Hold the two Ready Gelcassettes, or one Ready Gel cassette andbuffer dam, against the electrode assemblyand slide the electrode assembly into theclamping frame.
4. Press down on the outer edge of the electrode assembly, not the gels, while closing thecams of the clamping frame to ensure a sealon the bottom edge of each cassette.
5. Place the assembled clamping frame
containing the gel(s) into the gel box tank.
Fill the upper buffer chamber, the space
between the two gels, with ~150 ml 1X TGSelectrophoresis buffer, so the buffer level isabove the inner short plates. Check for leaks.
If the assembly is leaking, remove the assembled clamping frame, pour off the buffer,reopen the cams, and push down on the electrode assembly again while closing the cams.
6. Pour ~200 ml of 1X TGS electrophoresis
buffer into the lower buffer chamber, or tank.
Double-check the buffer fill level within theupper buffer chamber.

92

Note: If leakage of the upper buffer cannot
be corrected by reassembling the clamping frame in Step 4, the outer chamber canbe filled to above the inner small plates, toequalize the buffer levels in both reservoirs.
This requires approximately 900 ml of 1X
TGS electrophoresis buffer.

STEP 2: LOAD AND RUN GELS
Place a yellow sample loading guide on the
top of the electrode assembly. The guide will
direct the pipet tip to the correct position forloading each sample in a well.
Assign samples to wells, loading samples in
middle of the gel, where separation is bestwith the standards on each side. For example,
for five fish samples on a 10 well gel, you
may choose to follow this guide:

Lane

Volume Sample

1

Empty

None

2

Empty

None

3

5 μl

4

10 μl

Precision Plus Protein Kaleidoscope prestained standard
Fish sample 1

5

10 μl

Fish sample 2

6

10 μl

Fish sample 3

7

10 μl

Fish sample 4

8

10 μl

Fish sample 5

9

10 μl

Actin and myosin standard

10

Empty

None

To load each sample, use a thin, gel loading
micropipette tip to withdraw 10 μl of eachprotein sample from its tube and gently
transfer it into the designated gel well. Afterloading all samples, remove the sample loading guide, place the lid on the tank, and insert
the leads into the power supply, matching red
to red and black to black. Set the voltage to200V and run the gels for 30 minutes.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

Record your samples here:
Lane Sample
1. Precision Plus Protein Kaleidoscopeprestained standard
2. Precision Plus Protein Kaleidoscopeprestained standard
3. Precision Plus Protein Kaleidoscopeprestained standard
4. _________________________________
5. _________________________________
6. _________________________________
7. _________________________________
8. _________________________________
9. Actin and myosin standard
10. Precision Plus Protein Kaleidoscopeprestained standard

STEP 3: STAIN AND
VISUALIZE THE PROTEINS
Gel staining
1. When gels are finished running, turn off

the power supply and disconnect the leads.
Remove the lid and lift out the electrode assembly and clamping frame.
2. Pour out the running buffer from the electrode assembly. Open the cams and remove
the gel cassettes.
3. To keep the gel free of contamination fromyour fingertips, wear gloves to handle the gelsfrom this point on. Lay a gel cassette flat on
the bench with the short plate facing up. Cut
the tape along the sides of the gel cassette.
Carefully pry apart the gel plates, using aspatula or your fingertips. The gel will usuallyadhere to one of the plates. Transfer the platewith the gel adhering to it to a tray containing
Bio-Safe Coomassie stain, allowing the liquid
to detach the gel from the plate. The gel may
also be lifted directly (and gently!) from theplate and placed into the stain.
4. Allow the gels to stain for one hour, withshaking if available.
5. Your teacher will discard the stain andreplace it with a large volume of water todestain the gel overnight.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

93Name _______________________

Weigh Boat number __________________FROM FINCHES TO FISHES: DATA/OBSERVATION SHEET
5

6

7

8

9

10

Precision Plus Protein
Kaleidoscope standard

4

Actin and myosin standard

3

Precision Plus Protein
Kaleidoscope standard

2

Precision Plus Protein
Kaleidoscope standard

Precision Plus Protein
Kaleidoscope standard

1

FOCUS QUESTIONS
1. What are some important roles that proteins play in organisms?

2. Why did we apply heat and SDS buffer to the protein samples?

3. Why did we use a polyacrylamide gel instead of an agarose gel?

4. Which protein will travel further, a smaller protein or a larger protein?

5. What will the resulting protein bands help us to determine?

94© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

Name _______________________

Weigh Boat number _______________
KEY
9

10

Precision Plus Protein
Kaleidoscope standard

8

Actin and myosin standard

7

Fish sample #5

6

Fish sample #4

5

Fish sample #3

4

Fish sample #2

Precision Plus Protein
Kaleidoscope standard

3

Fish sample #1

2

Precision Plus Protein
Kaleidoscope standard

1

Precision Plus Protein
Kaleidoscope standard

FROM FINCHES TO FISHES: DATA/OBSERVATION SHEETFOCUS QUESTIONS
1. What are some important roles that proteins play in organisms?
Proteins such as enzymes acts as catalysts in biochemical reactions. Proteins also have structural and mechanical functions. Structural proteins include the keratin and collagen found in hair, skin, and fingernails. Actinand myosin are the principal fibrous proteins of muscle tissue; interaction of the actin and myosin brings aboutmuscle contraction and results in movement.
2. Why did we apply heat and SDS buffer to the protein samples?
The combination of heat and the addition of an ionic detergent, SDS (sodium dodecyl sulfate), act to denature
the proteins. The detergent coats dissolved proteins and polypeptides with negative charges. Heating causes
the proteins to lose their three dimensional structure and change to a linear structure. All of the net negativelycharged proteins move through the gel toward the positive electrode according to their size.
3. Why did we use a polyacrylamide gel instead of an agarose gel?
The polyacrylamide gels are used to separate smaller proteins. DNA and hemoglobin are much larger proteins
and are separated using agarose gels.
4. Which protein will travel further, a smaller protein or a larger protein?
Smaller proteins will travel further in the gel.
5. What will the resulting protein bands help us to determine?
Proteins from fish samples that are more closely related will have more bands in common. The size of the
bands can be used to determine the amounts of that particular sized protein. Proteins are synthesized according
to the genes of an organism’s DNA and similar proteins reflect similar DNA.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

95

PROTEIN PROFILER MODULE — QUICK GUIDE
From Bio-Rad’s Comparative Proteomics Kit I: Protein Profiler Module
1. Setup Mini-PROTEAN 3 gel box and add 1x TGS electrophoresis
buffer to the chamber.
2. Label one 1.5 ml flip-top micro tube for each of five fish samples.
Also label one screwcap microtube for each fish sample.
3. Add 250 μl of Bio-Rad Laemmli sample buffer to eachlabeled flip-top micro tube.
4. Cut a piece of each fish muscle about 0.25 x 0.25 x 0.25 cm3 andtransfer each piece into a labeled flip-top micro test tube. Close thelids.
5. Flick the microtubes 15 times to agitate the tissue in the sample
buffer.
6. Incubate for five minutes at room temperature.
7. Carefully transfer the buffer by pouring from each flip-top microtube into a labeled screwcap microtube. Do not transfer the fish!
8. Obtain the Kaleidoscope prestained standards (KS) and the actin
and myosin standard from your teacher.
9. Heat the fish samples and the actin and myosin standard (AM) inscrewcap microtubes for five minutes at 95°C.
10.Load your gel:
Lane
1&2
3

Volume*empty
5 μlSampleempty
Precision Plus Protein
Kaleidoscope standards (KS)4
10 μlfish sample 1
5
10 μlfish sample 2
6
10 μlfish sample 3
7
10 μlfish sample 4
8
10 μlfish sample 5910 μl
Actin and myosin standard (AM)
10
empty
empty
* — DESTINY has found that doubling the volume to 20 μl helps
students get enough protein out of the pipettes.
11. Electrophorese for 30 minutes at 200 V in 1x TGS electrophoresis buffer.
12. After electrophoresis, remove gel from cassette and transfer gel
to a container with 25 ml Bio-Safe Coomassie stain per gel and stain
gel for 1 hour, with gentle shaking for best results.
13. Discard stain and destain gels in a large volume of water for atleast 30 minutes to overnight, changing the water at least once. Bluestained bands will be visible on a clear gel after destaining.
14. Dry gels using GelAirTM cellophane.

96© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

From Finches to Fishes Equipment Needed for Wet-lab
VendorCatalog Number

Item

Unit

Minimum
Purchase

Price

TOTAL

REQUIRED EQUIPMENT
Bio-Rad164-5050EDUPowerPacTM Basic Power Supply

1$325.00

2$650.00

Bio-Rad165-3302EDU

Mini-PROTEAN 3 cell

1$238.00

8$1,904.00

Bio-Rad166-0506EDU

2-20 Digital micropipette1$159.00

8$1,272.00

Bio-Rad166-0507EDU

20-200 Digital micropipette (Instructor)

1$159.00

1$159.00

Bio-Rad165-3146EDU

10-well Sample Loading Guides

1

$8.80

8

$70.40EQUIPMENT TOTAL $4,055.40

REQUIRED CONSUMABLES
Bio-Rad166-2700EDU

Comparative Proteomics Kit I:
Protein Profiler module*

1$125.00

1$125.00

Bio-Rad161-1103EDU

Ready Gel precast gels 15%

1

$6.75

8

$54.00

CONSUMABLES TOTAL $179.00* — Protein Profiler module provides enough material for 8 workstations up to 32 students

OPTIONAL EQUIPMENT
Bio-Rad166-0709EDU

Rocking Platform

1$575.00

Bio-Rad166-0504EDU

Water Bath1$505.00

Fisher

11-718Dry Bath Incubator

1$251.88

Fisher

11-718-9

Heating block for 1.5mL microtubes

1$84.85OPTIONAL CONSUMABLES & REFILLS
Bio-Rad166-0010EDU

Actin & Myosin Standards

500μg$17.00

Bio-Rad161-0737EDU

Laemmli sample buffer

30mL

$9.60

Bio-Rad161-0375EDU

Precision Plus Protein Kaleidoscopeprestained standards

500μL$66.00

Bio-Rad161-0732EDUElectrophoresis Buffer, 10X

1L$17.60

Bio-Rad161-0786EDU

Bio-Safe Coomassie stain

1L$52.00© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

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FROM FINCHES TO FISHES IMPLEMENTATION PLAN — POST-LAB
Activity

Estimated
Time

Purpose/Objectives/
Essential Question

Materials/Equipment

Analyze polyacrylamide gels:
Use inquiry methods to encourage
students to analyze and discuss theirelectrophoresis results.
Polyacrylamide gels
• How many bands do similar looking
fish have in common?

Handout: Protein Fingerprinting:Analyzing Results of Gel Electrophoresis• Which fish have no bands in common?

Purpose:• Which fish appear to be related basedon the number of corresponding bands
or proteins?

Handout: What Do the Bands
Reveal? What Is the Significanceof Your Data?

To compare the protein
profile from five different
fish to determine phylogenic relationships.

Remind students that gel electrophoresis
of proteins does not provide any direct
information about amino acid sequences,and so cannot be used in any precise way
to reconstruct evolutionary history.

Rulers/magnifiers

Objectives:

30 minutes• To interpret the results ofelectrophoresis• To make inferences about
the relatedness of fish
based on the similarities of
their protein profiles.

Qualitative analysis of data

20 minutes

Worksheet: Interpreting the Bands

Detailed gel analysis

60 minutes

Worksheet: Analysis and interpretation of results

Essential Question:

CD provided

Which fish are most closely
related based upon theirprotein profile?

From Finches to Fishes Quiz Game

20 minutes

PBS Evolution Series Learning andTeaching Evolution, Video 1 onlyVideo Discussion questions
Isn’t Evolution Just a Theory? Video 1

20 minutes
Optional: Show video prior to
Additional Activity essay assignment
to incorporate into writing activity.

Alignment with NC Competency Goals
Biology
Goal 1
Objectives 1.01, 1.02, 1.03, 1.05
Goal 2
Objectives 2.01, 2.02, 2.03
Goal 3
Objectives 3.01, 3.04, 3.05

Goal 4
Objectives 4.01, 4.02, 4.03
Goal 5
Objectives 5.03

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99

ANALYZING RESULTS OF GEL ELECTROPHORESISAND DETERMINING SIGNIFICANCE OF DATAMATERIALS NEEDED• 1 Protein Fingerprinting: Analyzing Resultsof Gel Electrophoresis handout for each
student• 1 What Do the Bands Reveal? What Is the
Significance of Your Data? handout for each
student• Students’ gels from wet-lab• 1 ruler per student• 1 magnifying glass per student

BACKGROUND INFORMATIONFOR THE TEACHER
Similarities and differences between protein
fingerprints are easily spotted. By comparing
the banding pattern of the shark with otherfish it is clear that this fish is dissimilar fromall of the others. This is consistent with theproposed fish evolutionary tree, since theshark belongs to the Class Chrondrichthyes— cartilaginous fishes — as compared to theother species, which belong to the Class
Osteichthyses — bony fishes. Salmon andtrout, which are on the same branch, have
many similar bands. Swordfish and tuna,located on the same branch, show somesimilarities in their protein bands. By contrast, salmon and catfish, located on different
branches, reveal significant differences in100

their banding patterns. The actin and myosin
standard is included as a reference to help
identify the major, conserved muscle proteins
and to serve as a positive control for gel
analysis. This protein consists of myofibrils
isolated from rabbit skeletal muscle. The
Precision Plus Protein Kaleidoscopeprestained standards are included to provide
a means of practice for loading the samples
into the polyacrylamide ready gels and tohelp create a standard curve when graphing
the molecular weights of proteins.

INSTRUCTIONS FOR TEACHERS
Distribute the two handouts to the class (copyfrom notebook or print from module CD).
Use the Protein Fingerprinting handout toreview the process for analyzing results of gel
electrophoresis. Because the diagram on thishandout is clear and easy to read, it provides
a good opportunity to practice the techniqueof counting bands.
After practicing, students should count the
bands on their own gels, filling out the chart on
the What Do the Bands Reveal? handout. Afterthey have completed the chart and read the additional information on the significance of thedata, have them answer the three questions andthen review the results together as a class.

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PROTEIN FINGERPRINTING: ANALYZING RESULTS OF GEL ELECTROPHORESIS
Evolutionary biologists make hypotheses about relationships among different groups of organisms based on how
similar they are, in terms of both morphological and molecular traits. Below are the results of a gel electrophoresis
procedure, used to create protein “fingerprints” of several species of fish. By comparing the number of protein
bands that each kind of fish has in common with one another, you can make your own hypothesis about which ofthese fish are most closely related.

SAMPLE PROTEIN FINGERPRINTS

1

2

3

4

5

6

7

Myosin heavy chain
Actin
Tropomysosin

Myosin light chains

Lane: 1. Precision Plus Protein
Kaleidoscope standards
2. Shark

3. Salmon
4. Trout
5. Catfish

6. Swordfish
7. Actin and myosin standard© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

101WHAT DO THE BANDS REVEAL?
Using a ruler or straight edge, carefully count the number of bands that each kind of fish has in common with theothers. Do not include any of the bands in the actin and myosin standards in your counts, since every kind of fish hasthese bands. Then fill out the table below with your results. Which of these fish do you think are most closely related?

COMPARISON OF NUMBER OF SIMILAR PROTEIN BANDS FOUND IN FISH
Shark

SalmonTrout

CatfishSwordfish

Shark
SalmonTrout
CatfishSwordfish

WHAT IS THE SIGNIFICANCE OF YOUR DATA?
To make meaningful inferences about evolutionary relationships among the sample fish species, use a ruler anda magnifying glass to compare the banding patterns.
The actin and myosin standard is included as a reference to help identify the major, conserved muscle proteins and to serve as a positive control for gel analysis.
The Precision Plus Protein Kaleidoscope prestained
standards are included to provide a means of practicefor loading the samples into the polyacrylamide readygels and to help create a standard curve when graphing
the molecular weights of protein.
Gel electrophoresis is a powerful tool for separating andvisualizing the individual proteins in complex samples
like muscle tissue. The two types of molecules mostoften analyzed by electrophoresis are nucleic acids, like
DNA, and proteins. Electrophoresis not only lets you
determine how many distinct types of molecules are in
the sample, it can also tell you their sizes, which can bea clue to its identity.
The procedure that you have completed displays aprofile of protein composition in the muscle tissueof different fish. Since proteins are a reflection of anorganism’s DNA, variations in these composition
profiles indicates variations in DNA sequences.
Evolutionary relationships among species are inferred102

from the degree of genetic (DNA) similarity among
them. The protein fingerprints you’ve generated,indirectly representing the genetic compositions of yourchosen fish species, are molecular-level indicators of
evolutionary relationships.
Similarities and differences between protein fingerprints
are easily spotted.
1. Compare the banding pattern of the shark with otherfish samples. How might you explain any differences?

2. How does the salmon and catfish compare? Are they
located on the same branch?

3. Do the swordfish and tuna, located on the samebranch, show similarities in their protein bands?

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INTERPRETING THE BANDS COLLECTIVELY:QUALITATIVE COMPARISONS OF PROTEIN PROFILES
From Bio-Rad’s Comparative Proteomics Kit I: Protein Profiler Module
1. Is there any variation among the protein profiles of your samples?

2. How would you distinguish the protein profiles of different species from each other?

3. What are possible explanations for this variation?

4. Which samples are most alike?

Tape your gel or a photocopy
of it in the box. The bands are
the data upon which your analysis
will be based.

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103

ANALYSIS AND INTERPRETATION OF RESULTS: DETAILED GEL ANALYSIS
From Bio-Rad’s Comparative Proteomics Kit I: Protein Profiler Module
Does your molecular evidence support or refute your predictions?
Each protein band that a fish has in common with another fish is considered a shared characteristic. A fish family
tree, or cladogram, can be constructed based on proteins bands that the fish have in common. Cladistic analysis
assumes that when two organisms share a common characteristic that they also share a common ancestor with thatsame characteristic.
Create a cladogram using your results to find out.
From your gel you can create a cladogram based on proteins that the fish have in common. You can then determine
whether your cladogram supports your predictions and/or matches the evolutionary relatedness of the fish species determined by morphological analysis in the evolutionary tree provided. Each protein band that a fish has incommon with another fish is a shared characteristic. Cladistic analysis assumes that when two organisms share acharacteristic, they had a common ancestor that had that characteristic, and this can be represented as a node on acladogram with two branches coming from that node representing the descendent organisms.
In this exercise you will define the shared characteristics (i.e., make a list of all the different proteins in fish muscle),find which proteins (characteristics) are shared between fish, and construct a cladogram based on your data.

PROCEDURES
Generate a standard curve to calculate protein molecular weights(Optional) Although it is not strictly necessary for this exercise, you may want to create a standard curve from yourgel and determine the actual size of each protein band.
Alternatively, the cladogram can be generated just using the distance in millimeters the different protein bands havemigrated from the wells of the gel.
To create the standard curve measure and record the distances the five visible protein bands contained in the Precision Plus Protein Kaleidoscope prestained standards. Start from the green 37 kD band down to the yellow 10 kD
band that has migrated from the wells. Accuracy to 0.5 mm is required.

Precision Plus Protein Kaleidoscope Prestained Standards Molecular Weight (kD)Distance Migrated (mm)

37
25
20
15
10

104

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On the graph paper provided, plot the distances migrated in mm on the x-axis against the molecular weight of the
bands in kD on the y-axis as a scatter plot.
Draw a line through the points. On a logarithmic scale, plotting the molecular weights against the distances migrated
for each protein in the standard should result in a linear (straight line) curve. Alternatively, you can use a graphing computer program to generate the chart and make a line of best fit (or a trend-line) through these points and toformulate an equation to calculate the MW of the unknown proteins on the gel.

ANUAL

100
90
80
70
60

50

40

30

20

Protein Molecular Mass (kD)

10
9
8
7
6
5

4

3

2

1
5

10

15

20

25

30

35

40

45

50

Distance Migrated (mm)

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105

Define the characteristics (proteins) of the different fish
Make a horizontal line on the dried gel (or gel image) between the 37 kD (green) and 25 kD (pink) markers below
the fat bands that occur at around 30 kD (see gel above). Then, for each band below the line for each fish sample,
measure the distance the protein band has migrated from the wells (and, if required, determine its size in kD using
the standard curve or the formula generated from the standard curve) and record this data (see example below):

Distance protein
bands migrated(mm)

Species A

Species B

Species C

Species D

Species E

25, 26.5, 29, 36,36.5, 39, 44, 52

26, 27.5, 29, 32,
34.5, 36.5, 37.5,
40.5, 42, 45

26, 27.5, 29,29.5, 32, 34.5,
36.5, 37.5, 40.5,
42, 45, 46.5, 51.5

26, 27.5, 29, 32,
36.5, 38, 38.5,
41, 46, 47.5,
44, 4726, 27.5, 30,
30.5, 33, 35.5,
37, 39, 39.5, 42

Record your data in the table below:

Distance protein
bands migrated(mm)

Determine which fish have each characteristic (protein)
In the blank table provided on page 108, use one row for every band size you have recorded and one column foreach type of fish on your gel. Then make a mark in each cell of the table where the fish has that size band (see example on next page).

106© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

CHARACTERISTIC

Example:Distance
Migrated (mm)Protein Molecular
Mass (kDa)

25
26
26.5
27.5
28.5
29
30
30.5
32
33
34.5
35.5
36
36.5
37
37.5
38
38.5
39
39.5
40.5
41
41.5
42
43
44
45
46
46.5
47
47.5
51.5
52

32.5
31.5
31.0
30.0
29.1
28.6
27.6
27.1
25.6
24.7
23.2
22.2
21.7
21.2
20.7
20.2
19.7
19.3
18.8
18.3
17.3
16.8
16.3
15.8
14.8
13.9
12.9
11.9
11.4
10.9
10.4
6.5
6.0
COUNT

Species A

Species B

Species C

Species D

Species E

X

X

X

X

X

X

X

X

X

X
X

X

X

X

X
X

X

X

X
X
X

X

X
X

X
X

X

X

X

X

X
X
X
X

X

X
X
X

X
X

X

X

X

X

X
X

X
X
X
X
X
X

X
8

10

13

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10

12

107

Record your data in the table below:
Protein Molecular
Mass (kDa)

CHARACTERISTIC

Distance
Migrated (mm)108

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Find the number of characteristics shared by each of the fish
In the table below both the row and column headings are the types of fish. From the table on page 105, separately
compare the number of bands (X’s) in common with every other fish sample from your gel and put those numbers
into the table below, such that each fish is individually compared with every other fish. In this example, species A
and B have just two bands in common while species B and C have 10 bands in common. The table below will be thebasis for drawing your cladogram.

Species A

Species B

Species C

Species D

Species E

8

2

2

2

2

10

10

5

3

13

5

4

10

2

Species A
Species B
Species C
Species D
Species E

12Record your data in the table below:

Construct your cladogram
Now you are ready to construct your cladogram. First draw a line to form the trunk of your cladogram. Find the fishwith the least bands in common. In the example above it is species A, which has only 2 bands in common with anyof the other fish. Then draw a side branch off the line near the bottom of the trunk and label that branch with thefish’s name, in this case, species A. This fish is the outlier, i.e., it is the least similar to any of the others. The node
(where the side branch meets the trunk) represents an ancestor that is common to all the fish in this analysis.

A© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

109

Find the two fish with the most bands in common (in this example it is species B and C, which have 10 bands incommon). Draw a side branch off the trunk near the top and label the two ends with the fishes’ names, in this case,species B and species C (it doesn’t matter which branch gets which label). The node represents a common ancestorof species B and species C that had all the same characteristics (proteins).

C

A

B

Identify those fish species with the next most bands in common. In this example, species D has five bands incommon with species B and species C, which indicates species D is the same cladistic distance from B and C (i.e.
species D is not more closely related to either B or C). Draw a branch further down the trunk. This node represents
an ancestor that is common to species B, C, and D that had these 5 characteristic proteins.

A

110

D

C

B

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The last fish to add to the cladogram in this example is species E, which shares four bands with species C, threebands with species B, and only two bands with species A and D. This fish may seem trickier to place than the others
because it shares more characteristics with species B and C than it does with D, but D shares more characteristics
with B and C than E does. So, to place this fish you might ask: Does species E share the five proteins that the common ancestor of species B, C, and D had? Answer (no).
Does species E share more proteins with B, C, and D than A? Answer (yes). Therefore, species E gets its own branch
in between the D and A branches to indicate that it has more shared characteristics with B, C, and D than A, but
fewer shared characteristics with B and C than D.

A

E

D

C

B

Using your own data, draw a cladogram below.

Compare your cladogram with your original predictions. Write your deductions below.

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111

From Finches to Fishes Quiz Game Questions
Evolution

200

400

600

800

1000

112

Proteins andSuch

Wet-LabProteinFingerprinting

Dictionary

Hodge
Podge

Who first developed
the theory of evolution through natural
selection?

Fact or fiction?
Proteins accountfor more than 95
percent of the dryweight of most cells.

Fill in the blank:
The process usedin the wet-lab toobtain a protein
fingerprint is called
gel ______.

Fill in the blank:
Gel electrophoresis
is used to separate
proteins according
to ________.

Define evolution.

How many friction
stops were on theplunger of the
micropipette used in
the wet lab?

What was the nameof the ship that Darwin sailed on during
the voyage that led
to his developmentof his theory of
evolution throughnatural selection?

What are proteins?

In the wet-lab weused digital micropipettes, whichmeasure very small
quantities of liquid.
What units do themicropipettes use tomeasure?

In protein fingerprinting, which
proteins traveledfurther on thepolyacrylamide gel,small ones or large
ones?

What is the term fora sequence of DNA
that codes for a protein and determinesa trait?

Convert 2.7 milliliters
to microliters.

What is the term
for the study of
evolutionary
relationships amongorganisms?

How does DNA code
for a specific trait
such as hair color?
(Hint: creation ofproteins is one step)

Heat and SDS buffer
were applied to
our fish protein
samples for what
two reasons?

What piece ofequipment wasused to placesamples of protein
into the wells of thepolyacrylamide gel?

What is genetic
drift?

During the wet-lab,
one well contained
actin and myosin;
what are actin andmyosin?

Name three adaptations in birds that
may give them an
evolutionary advantage over otherorganisms.

How can proteins beused to determine
evolutionary
relationships amongorganisms?

Why were polyacrylamide gels used in
the wet-lab insteadof agarose gels?

Why is it necessarythat polyacrylamidegels be stained anddestained after
protein electrophoresis?

Definespeciation.

The “fishy familytree” you looked at
before the wet-lab
used morphologicaltraits to show relationships between
organisms, what ismorphology?

Explain Darwin’s
theory of evolution
through natural
selection.

Name four ways inwhich proteins areused in our bodies.

According to the results of the wet-lab,which fish appear tobe the most closely
related? Explain
your answer.

Why is the processused in the wet-lab
called protein
fingerprinting?

Define adaptive
radiation.

The field of comparative anatomy uses
occurrences ofhomologous andanalogous structuresin different species asevidence that thosespecies evolved fromsimilar or different
ancestors. Whatis the difference
between homologous and analogous
structures?

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Finches to Fishes Quiz Game Answers
Evolution

Hodge
Podge

Dictionary

Fiction. Proteinsaccount for 50% of thedry weight of a cell.

Electrophoresis.

Size.

A change in thefrequency of a trait(gene) within apopulation.

2.

The HMS Beagle.

Organic molecules thatare made of aminoacids held together by
peptide bonds.

Microliters.

Small proteins.

Gene.

2.7 ml = 2700 μl.

Phylogeny.

DNA is used to create mRNA. mRNA
codes for a specificcombination of aminoacids. Those aminoacids form proteins.
Proteins act bythemselves or in
combination withother proteins to givean organism a trait (forinstance hair color).

The heat and SDS buffer made the proteins
linear and negatively
charged.

Micropipette.

Changes in the genepool of a small population due to chance.

Actin and myosin areproteins found in themuscle tissue of manyorganisms.

Answers may vary.
Examples: Wings,
feathers, hollow bones
for flight; beaks, claws
for digging for food;talons for hunting;camouflage coloring.

One of 2 answers
would be correct. 1)
The number of shared
proteins between organisms can illustrate
relative relatedness. 2)
The number of aminoacid differences in asingle protein between
2 species can tell you
how long ago the 2
species diverged.

Polyacrylamide gelswere used because
they are more effective
for smaller molecules,
such as proteins.

So that the proteinscan be seen as bandson the gel.

The origin of new
species in evolution.

The branch of biologythat deals with theform and structure oforganisms without
consideration of function. An example of amorph trait is a fish’s
mouth shape.

Darwin’s theory canbe summarized in 4
points:
1. Variations exist
among individuals 2.
Organisms produce
more offspring thanthe environment can
support 3. Competition
exists among individuals 4.The organisms
whose variations
best adapt them tothe environment are
the ones who aremost likely to survive
reproduce, and pass ondesirable traits to thenext generation.

Answers may vary, but
may include: proteinsas part of hair, muscle,
fingernails, or as enzymes, neurotransmitters, hormones, etc. In
cells proteins are used
for structural support,
storage, transport ofsubstances, movementand defense against
foreign substances.

The answers to thisquestion will varydepending on the fishproteins used. The
students should justify
their answer by statingthat the percentage
of proteins sharedby those two fish is
greater than any othercombination of fish.

It’s called protein
fingerprinting because
the technique leaves
a banding pattern on
the gel where the proteins were separated
by size. This banding
pattern is unique toeach species of fish,
just like a fingerprint is
unique to each human.

A relatively rapid
evolution of many
species from a single
ancestor.

Homologous structuresare similar features on
different species that
don’t have the sameuse (forelimbs onalligator and human).
Analogous structuresare similar structureswith the same purpose(wings on insects andbirds).

400

600

1000

Wet-LabProteinFingerprinting

Charles Darwin.

200

800

Proteins and
Such

KEY

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113

DISCUSSION QUESTIONS: ISN’T EVOLUTION JUST A THEORY?
From PBS Evolution Series: Learning and Teaching Evolution
1. How does the scientific meaning of a term like “theory” differ from the way it is used in everyday life?

2. Can the “facts” of science change over time? If so, how?

114

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FROM FINCHES TO FISHES IMPLEMENTATION PLAN — ADDITIONAL ACTIVITIES & RESOURCES
Activity

Est.
Time

Materials/Equipment

Subjects
CoveredSuggestions
Additional summative
assessment

Essay applying learned vocabulary, evolutionary
process, and scientific concepts

50 minutes

Rubric for essay,
Text Book,
Internet Access

Evolution, writing skills,
computer skills

Creating cladograms
Students use taxonomic information from the
BLAST databases to create a phylogenic tree.

60 minutes

Handouts: Using Databases to Obtain
Real Amino Acid Sequence Data to
Create Cladograms

Technology,
bioinformatics

Peppered Moth Game

20 minutes

www3.district125.k12.il.us/faculty/nfischer/Moth/default.htm

Evolution, molecularbiology

Chromosome Connections
How closely related are we to other primates?
Students will match up chromosomes to determine
which primate is our closest living relative.

30 minutes

Internet accesswww.becominghuman.org(Click on “learning center” and thenon “lesson plans”.)

Molecular biology, genetics, process ofscience, computer skills

Building Bodies
Humans and other hominids evolved unique skeletal
30 minutes
adaptations. Students will “build” two skeletons— one of an ape and one of a modern human.

Internet accesswww.becominghuman.org(Click on “learning center” and thenon “lesson plans.”)

Human anatomy andphysiology, evolution,
computer skills

Calculating Cousins
Although fossils can be accurately dated, the lines ofdescent between species are widely debated. How a
30 minutes
hominid family tree is drawn depends on the current
fossil evidence. Students will evaluate fossil evidence
and map out the history of the hominid family tree.

Internet accesswww.becominghuman.org(Click on “learning center” and thenon “lesson plans.”)

Evolution, genetics,
pedigrees, human biology,
genealogy, taxonomy,
computer skills

Evidence for Evolution WebQuest
Students will investigate a variety of evidence for
evolution. Each team will be responsible for learning 50 minutes
about fossil evidence, structural evidence, and genetic
evidence and presenting the information to the class.

Internet accesswww.pbs.org/evolution
Large paper (24-46)
Markers, rulers

Evolution, earth science,
anatomy, presentation
skills, computer skills

Evolution and Time
Students act as paleontologists investigating aparticular period of time in Earth’s history. Students
50 minutes
visit their chosen time period and make a detailed
journal entry of what they “see.” Students also createa “Geologic Birthday Card.”

Calculator,
Evolution, earth
Paper (8½” X11”)
science, math, art,
Markers, crayons, scissors, magazines,
writing skills
glue

How Much Variation? Doing the MathStudents examine variation in a 1,691-basesegment of the beta globin gene to consider theextent of human genetic variation at the molecular level and the relationship between genetic
variation and evolution.

20 minutes

Student Activity Sheet from NIH
Curriculum Supplement Series:
Human Genetic Variation

Genetics, molecularbiology, math skills

Alike, But Not the Same

20 minutes

Student Activity Sheet from NIH
Curriculum Supplement Series:
Human Genetic Variation

Genetics

Comparative Proteomics Kit II:
Western Blot Module

Optional: Show Isn’t
Evolution Just a Theory?
video prior toassigning essay

Compartive Proteomics Kit II from
Bio-Rad; Cat # 166 -2800EDU

Additional Resources:
Evolution Web features, articles images, and more … all easily accessible by going to: http://www.pbs.org/evolution. Then go to Evolution Teachers Guide: where you
will find the Teacher’s Guide Web Resources organized by unit.
Human Evolution website: www.becominghuman.org
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115

FROM FINCHES TO FISHES
A general rubric used for scoring the evolution essay
CONCEPTS/VOCABULARY TO BE INCLUDEDMAXIMUM 5 POINTS EACH

Environment and conditions for survival
Descent with modification
Adaptations, fitness
Isolating mechanisms
Definition of evolution
Evidence for evolution
Modification by natural selection
Relatedness vs. common ancestor
Species, subspecies, speciation
Adaptive radiation
Extinction
Genetic drift

PRESENTATION FORMAT
Overall use of scientific terms and scientific thinking
Use of observations to support statements
Spelling and punctuation
Sentence structure
GrammarOrganization of topics and subtopics
Use of additional evidence to support statements
Overall presentation and writing format

Total Points

116© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

USING DATABASES TO OBTAIN REAL AMINO ACID SEQUENCE DATA TO CREATE CLADOGRAMS
From Bio-Rad’s Comparative Proteomics Kit I: Protein Profiler Module
In order to determine how closely related species are,scientists often will study amino acid sequences of
essential proteins. Any difference in the amino acidsequence is noted and a phylogenetic tree is constructedbased on the number of differences. More closely related species have fewer differences (i.e., they have moreamino acid sequence in common) than more distantly
related species.
There are many tools scientists can use to compareamino acid sequences of muscle protein. One such tool
is the National Center for Biotechnology Information
protein databases (http://www.ncbi.nlm.nih.gov/). By
entering the amino acid sequence of a protein you areinterested in, the BLAST search tool compares that sequence to all others in its database. The data generated
provides enough information to construct cladograms.
The purpose of this activity is to use data obtained fromNCBI to construct an evolutionary tree based on theamino acid sequences of the myosin heavy chain. In
this example we have input a 60 amino acid sequence
from myosin heavy chain of rainbow trout and thenpulled out matching sequences using BLAST, which
include chum salmon, zebra fish, common carp, andbluefin tuna, and then compared each of these sequences with each other.
You may either use the data provided below or haveyour class go online and obtain their data directly by
performing BLAST searches. A quick guide to performing BLAST searches is given at the end of this activity.
The data below was obtained by entering a 60 aminoacid sequence from the heavy myosin chain of rainbow
trout. The database search tool returned all sequencesthat were a close match. The results are formatted assuch:

gi|755771|emb|CAA88724.1 myosin heavy chain [Oncorhynchus mykiss]
Length=698
Score = 119 bits (299), Expect = 2e-26
Identities = 60/60 (100%), Positives = 60/60 (100%), Gaps = 0/60 (0%)
Query 1
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL 60
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL
Sbjct 1
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL 60

The value for “identities” is the number of aminoacids exactly in common, the value for “positives”
is the number of amino acids that are similar to eachother (such as serine and threonine), and the value for‘gaps’ is the number of amino acid positions that areabsent one of the sequences. “Query” is the original
trout sequence, “Sbjct” is the aligned sequence, and the
middle sequence shows the mismatches: a “+” indicatesa positive and a space indicates a mismatch that is nota positive. There are resources on the NCBI website
to help you understand more about the information a
BLAST search generates.
The data on the following pages compares rainbow
trout to salmon, zebra fish, carp, and tuna, and thencompares salmon to zebra fish, carp, and tuna, thenzebra fish to carp and tuna, and finally carp to tuna.
Use the data provided to determine how many aminoacid differences exist between the organisms. Organize
your data in charts.

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117

Rainbow trout compared to chum salmon

Chum salmon compared to common carp

gi|21623523|dbj|BAC00871.1| myosin heavy chain [Oncorhynchus keta]

gi|806515|dbj|BAA09069.1| myosin heavy chain [Cyprinus carpio]
Length=955

Length=1937
Score = 119 bits (299), Expect = 2e-26
Identities = 60/60 (100%), Positives = 60/60 (100%), Gaps = 0/60 (0%)

Score = 104 bits (259), Expect = 8e-22
Identities = 51/60 (85%), Positives = 56/60 (93%), Gaps = 0/60 (0%)

Query 1AKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL 60
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL

Query 1
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL 60
VAKAK NLEKMCRTLEDQLSE+KTK+DENVRQ+ND++ QRARL TENGEF RQLEEKEAL

Sbjct 1240
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL 1299

Sbjct 259
VAKAKANLEKMCRTLEDQLSEIKTKSDENVRQLNDMNAQRARLQTENGEFSRQLEEKEAL 318

Rainbow trout compared to zebra fish

Chum salmon compared to zebra fish

gi|68360600|ref|XP_708916.1| PREDICTED: myosin, heavy polypeptide 1,

gi|68360600|ref|XP_708916.1| PREDICTED: myosin, heavy polypeptide 1,

skeletal muscle [Danio rerio]

skeletal muscle [Danio rerio]

Length=2505

Length=2505

Score = 108 bits (269), Expect = 6e-23
Identities = 52/60 (86%), Positives = 57/60 (95%), Gaps = 0/60 (0%)

Score = 108 bits (269), Expect = 6e-23
Identities = 52/60 (86%), Positives = 57/60 (95%), Gaps = 0/60 (0%)

Query 1
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL 60
VAKAK NLEKMCRTLEDQLSE+K+KNDEN+RQ+ND+S QRARL TENGEFGRQLEEKEAL

Query 1
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL 60
VAKAK NLEKMCRTLEDQLSE+K+KNDEN+RQ+ND+S QRARL TENGEFGRQLEEKEAL

Sbjct 1240
VAKAKANLEKMCRTLEDQLSEIKSKNDENLRQINDLSAQRARLQTENGEFGRQLEEKEAL 1299

Sbjct 1240
VAKAKANLEKMCRTLEDQLSEIKSKNDENLRQINDLSAQRARLQTENGEFGRQLEEKEAL 1299

Rainbow trout compared to common carp

Chum salmon compared to bluefin tuna

gi|806515|dbj|BAA09069.1| myosin heavy chain [Cyprinus carpio]

gi|1339977|dbj|BAA12730.1| skeletal myosin heavy chain [Thunnus thynnus]
Length=786

Length=955
Score = 104 bits (259), Expect = 8e-22
Identities = 51/60 (85%), Positives = 56/60 (93%), Gaps = 0/60 (0%)

Score = 104 bits (259), Expect = 8e-22
Identities = 49/60 (81%), Positives = 57/60 (95%), Gaps = 0/60 (0%)

Query 1
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL 60
VAKAK NLEKMCRTLEDQLSE+KTK+DENVRQ+ND++ QRARL TENGEF RQLEEKEAL

Query 1
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL 60
VAK+KGNLEKMCRT+EDQLSELK KNDE+VRQ+ND++GQRARL TENGEF RQ+EEK+AL

Sbjct 259
VAKAKANLEKMCRTLEDQLSEIKTKSDENVRQLNDMNAQRARLQTENGEFSRQLEEKEAL 318

Sbjct 88
VAKSKGNLEKMCRTIEDQLSELKAKNDEHVRQLNDLNGQRARLQTENGEFSRQIEEKDAL

Rainbow trout compared to bluefin tuna

Zebra fish compared to common carp

gi|1339977|dbj|BAA12730.1| skeletal myosin heavy chain [Thunnus thynnus]

gi|806515|dbj|BAA09069.1| myosin heavy chain [Cyprinus carpio]

147

Length=955

Length=786
Score = 104 bits (259), Expect = 8e-22
Identities = 49/60 (81%), Positives = 57/60 (95%), Gaps = 0/60 (0%)

Score = 108 bits (271), Expect = 4e-23
Identities = 53/60 (88%), Positives = 59/60 (98%), Gaps = 0/60 (0%)

Query 1
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL 60
VAK+KGNLEKMCRT+EDQLSELK KNDE+VRQ+ND++GQRARL TENGEF RQ+EEK+AL

Query 1
VAKAKANLEKMCRTLEDQLSEIKSKNDENLRQINDLSAQRARLQTENGEFGRQLEEKEAL 60
VAKAKANLEKMCRTLEDQLSEIK+K+DEN+RQ+ND++AQRARLQTENGEF RQLEEKEAL

Sbjct 88
VAKSKGNLEKMCRTIEDQLSELKAKNDEHVRQLNDLNGQRARLQTENGEFSRQIEEKDAL

Sbjct 259
VAKAKANLEKMCRTLEDQLSEIKTKSDENVRQLNDMNAQRARLQTENGEFSRQLEEKEAL 318

118

147

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Zebra fish compared to bluefin tuna

Common carp compared to bluefin tuna

gi|1339977|dbj|BAA12730.1| skeletal myosin heavy chain [Thunnus thynnus]

gi|1339977|dbj|BAA12730.1| skeletal myosin heavy chain [Thunnus thynnus]

Length=786

Length=786

Score = 102 bits (253), Expect = 4e-21
Identities = 47/60 (78%), Positives = 57/60 (95%), Gaps = 0/60 (0%)

Score = 104 bits (259), Expect = 9e-22
Identities = 49/60 (81%), Positives = 57/60 (95%), Gaps = 0/60 (0%)

Query 1
VAKAKANLEKMCRTLEDQLSEIKSKNDENLRQINDLSAQRARLQTENGEFGRQLEEKEAL 60
VAK+K NLEKMCRT+EDQLSE+K+KNDE++RQ+NDL+ QRARLQTENGEF RQ+EEK+AL

Query 1
VAKAKANLEKMCRTLEDQLSEIKTKSDENVRQLNDMNAQRARLQTENGEFSRQLEEKEAL 60
VAK+K NLEKMCRT+EDQLSE+K K+DE+VRQLND+N QRARLQTENGEFSRQ+EEK+AL

Sbjct 88
VAKSKGNLEKMCRTIEDQLSELKAKNDEHVRQLNDLNGQRARLQTENGEFSRQIEEKDAL

Sbjct 88
VAKSKGNLEKMCRTIEDQLSELKAKNDEHVRQLNDLNGQRARLQTENGEFSRQIEEKDAL

147

147

Construct a table of your data containing the number of amino acid differences between each of the different fish.

Rainbow trout

Chum salmon

Zebra fish

Common carp

Bluefin tuna

Rainbow trout
Chum salmon
Zebra fish
Common carp
Bluefin tuna
Which two fish share the most amino acids in their myosin heavy chains based on your data?

Which two fish share the fewest amino acids?

Are there any fish that share more amino acids with each other than each does with the two fish in question one? If
yes, which fish?

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

119Construct a cladogram based on this data:

The myosin heavy chain of white croaker (Pennahia argentata) (BAB12571) has the following amino acid differences with the five fish above.

White croaker

Rainbow trout
4

Chum salmon
4

Zebra fish
11

Common carp
9

Bluefin tuna
11

Add this fish to your cladogram and explain why you placed it where you did.

120

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Construct a table of your data containing the number of amino acid differences between each of the different fish.

Rainbow trout
Chum salmon
Zebra fish
Common carp
Bluefin tuna

Rainbow trout
0

Chum salmon
00Zebra fish880Common carp
99
70

Bluefin tuna
11
11
13
11
0

Which two fish share the most amino acids in their myosin heavy chains based on your data?
Trout and salmon
Which two fish share the fewest amino acids?
Tuna and zebra fish
Are there any fish that share more amino acids with each other than each does with the two fish in question one? If
yes, which fish?
Yes, carp and zebra fish
Construct a cladogram based on this data:tuna

carp zebrafish

croakersalmon© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

trout

121

KEY

Taxonomic data can be derived from many sources:
DNA sequences, protein sequences, morphology, andpaleontology. Classification of organisms derives fromthese sources. Inconsistencies in the phylogenetic trees
generated between molecular and taxonomic data emphasize why data from different sources is required togenerate phylogenetic trees and why there is still muchdispute in the field of phylogenetics on the correct
placement of organisms within phylogenetic trees. The
amount of work required to process the small amountof data provided here also emphasizes the need forskilled bioinformaticists to process and analyze the vast
amount of data generated by genomic and proteomic
research.
Examine the taxonomic classification of the fishes
below and construct a phylogenetic tree based on that
data. The large phylogenetic tree figure will be usefulfor this exercise.
Rainbow Trout (Oncorhynchus mykiss) Vertebrata;
Euteleostomi; Actinopterygii; Neopterygii; Teleostei;
Euteleostei; Protacanthopterygii; Salmoniformes; Salmonidae; Oncorhynchus.
Chum Salmon (Oncorhynchus keta) Vertebrata; Euteleostomi; Actinopterygii; Neopterygii; Teleostei; Euteleostei; Protacanthopterygii; Salmoniformes; Salmonidae;
Oncorhynchus.

Zebra Fish (Danio rerio) Vertebrata; Euteleostomi;
Actinopterygii; Neopterygii; Teleostei; Ostariophysi;
Cypriniformes; Cyprinidae; Danio.
Carp (Cyprinus carpio) Vertebrata; Euteleostomi;
Actinopterygii; Neopterygii; Teleostei; Ostariophysi;
Cypriniformes; Cyprinidae; Cyprinus.
Bluefin Tuna (Thunnus thynnus) Vertebrata; Euteleostomi; ctinopterygii; Neopterygii; Teleostei; Euteleostei;
Neoteleostei; Acanthomorpha; Acanthopterygii; Percomorpha; Perciformes; Scombroidei; Scombridae; Thunnus.
White Croaker (Pennahia argentata) Vertebrata; Euteleostomi; ctinopterygii; Neopterygii; Teleostei; Euteleostei;
Neoteleostei; canthomorpha; Acanthopterygii; Percomorpha; Perciformes; Percoidei; Sciaenidae; Pennahia.
Does the taxonomic classification support the moleculardata?

Why do scientists need to examine multiple data sets
before determining evolutionary relatedness?

QUICK GUIDE TO BLAST SEARCHING
Please note, this is a quick guide to obtain a list of fish
myosin sequences, there are many refinements you canmake to your search and many different ways to use
BLAST searches.
Further information can be found on the NCBI website.
1) Go to http://www.ncbi.nlm.nih.gov/ and choose
BLAST.
2) Choose Protein-Protein BLAST.
3) Enter your myosin sequence into the search box.
Rainbow Trout Myosin Heavy Chain Protein Sequence(CAA88724):
VAKAKGNLEKMCRTLEDQLSELKTKNDENVRQVNDISGQRARLLTENGEFGRQLEEKEAL
4) Leave the other fields as found and hit the BLAST
button.
5) A new window should pop up. Hit the Format button.

1226) After a short wait the BLAST results window will
come up and may well be hundreds of pages long
— don’t worry. There should be a long list of sequencesthat produced significant alignments. Although thesearch may pick up hundreds of sequences, they are inorder of homology, so the ones you are interested inshould be in the first 25 or so.
7) Further down the BLAST results page, after the listof sequences, each sequence will be aligned with theoriginal trout sequence (as shown in the example) sothat you can see how the two compare.
8) To compare your second fish, say bluefin tuna, withthe other fish, you must perform a second BLAST
search with the tuna sequence to obtain the proteinalignments of tuna with the other fish. Alternatively,
you can align 5 protein sequences yourself from youroriginal search in a word processing document (useCourier font, this aligns sequences because all the letters are the same width) and have your students manually compare them.

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BLAST-SEARCHING QUESTIONS
Construct a simple phylogenetic tree based on the taxonomic data.

Does the taxonomic data support the molecular data? Please explain your answer.

Why do scientists need to examine multiple data sets before determining evolutionary relatedness?

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123

ANSWERS TO BLAST-SEARCHING QUESTIONS
Construct a simple phylogenetic tree based on the taxonomic data (the large phylogenetic tree figure will be useful here).

carp

zebra fishtuna

croakersalmonPerciformes

Acanthopterygii

trout

Salmoniformes

Protacanthoptrygii

Cypriniformes

Ostariphysi
Euteleostei

Teleosti

Does the taxonomic data support the molecular data? Please explain your answer.
The trees do not entirely match. Both trees show a close relationship between salmon and trout and zebra fish
and carp. However, tuna is in the same sub-phylum (Euteleostei) as salmon and trout, yet this does not concurwith the molecular data and croaker is in the same order as tuna (Perciformes) and yet the amino acid sequenceof croaker’s myosin is much closer to salmon than tuna.
Why do scientists need to examine multiple data sets before determining evolutionary relatedness?
The statistical relevance of data grows as the size of the data set increases. The 60 amino acid segment of myosin
heavy chain constitutes just 3% of the myosin heavy chain molecule, which is around 1,900 amino acids long.
Performing a BLAST search with a larger portion of the molecule generates a cladogram with different relationships, demonstrating that the 60 amino acid piece is not large enough to provide a full picture of relatedness.
However, even if the full-length myosin were compared, that is just a single protein out of the thousands generated by the organism. The data would be much stronger if the sequences of multiple proteins were compared andstronger still if molecular data were used with other types of classification data such as morphological data.

124© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

KEYDarwin, the Writer

X

X

X

Social Studies

X

Math

X

HealthEnglishPicture This: A Writing and
Listening Exercise for Scienceand Non-Science Classrooms

Arts

Activity

Science

FROM FINCHES TO FISHES IMPLEMENTATION PLAN — INTERDISCIPLINARY BRIDGES

Provided materials

Picture This handout

X

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125

PICTURE THIS
A Writing and Listening Exercise for
Science and Non-Science Classrooms
Subjects: English, Biology

Biological evolution — or, indeed, any complicated or controversial topic — can present
an opportunity for teachers to help students
develop skills as critical thinkers, thoughtful writers,
and good listeners. Perhaps this last set of skills is themost vital of the three — as throughout their lives yourstudents will benefit from an ability to listen respectfully and mindfully when other people express views
and ideas that may seem to differ from their own.
Picture This serves several functions. This activity calls
upon students to stretch linguistically and imaginatively—to use a range of vocabulary that typical classdiscussion might not require of them, and to makecreative connections between what they already feel,
think, and know and what they are about to learn. As
its name suggests, Picture This enables students who
are more visually oriented to relate images to ideas.
And, like other activities recommended by DESTINY,
it encourages active participation by all the students inyour class.
We recommend this activity as a starting point for yourevolution unit in a biology class. If you are a non-science teacher, you may find Picture This to be useful atthe beginning of a unit involving an evolution-themed
literary work (such as Inherit the Wind, The Time
Machine, or Cosmicomics) or argumentative communication (such as an editorial, speech, or letter). However,Picture This can be adapted for a number of classroom
uses. Though biological evolution is the topic described
here, this writing and listening exercise will work wellto engage students in many other topics and assignments.

RESOURCES• A large selection of photographs you have cut frommagazines or catalogues. Almost any weekly or monthly magazine (Time, People, Sports Illustrated, Smithsonian, etc.) and many catalogues (particularly those thatare related to travel or gardening) will yield images thatare useful for Picture This.

126

So that your students will have a number of images
from which to choose, provide two or three photographs
per student (e.g., fifty or sixty photographs for a classof twenty-five students). The photographs should offer
a range of images: landscapes, cityscapes, animals, machinery, objects, abstractions, and ordinary people (notcelebrities or other people your students will recognize)
in interesting situations or against interesting backdrops. These should be images your students can invest
with their own thoughts and feelings.
• Picture This handout: enough copies so that each
student has one to write on. (If you are unable to makecopies of the Picture This handout, you can write thequestions on your blackboard or on a transparency.
Students can write their answers and glue their pictures
on loose sheets of blank paper or in their journals.)• Glue sticks: five or six for the class to share, so thatyour students can affix the photographs they select totheir Picture This handouts.

ACTIVITIES/PROCEDURES
WHAT YOU DO
Display all the photographs on a large surface (a counter, several empty student desks, or even the floor will

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

work). Invite your students to come forward and survey
the photographs. Ask each student to select the photograph that best illustrates or symbolizes her feelings orideas about evolution. Give your students time to lookat the pictures and to give some thought to their selection process. Each student selects one photograph.
Variation: Group Work. Divide your class into groupsof five or six students. Give each group ten or twelve
photographs. Ask the group to choose a photograph that
represents the group’s views. Have each group report tothe class on its answers to the Picture This handout.

WHAT YOUR STUDENTS DO
This activity is divided into Writing and Listening
phases that enable all students to participate equally andsimultaneously.
Writing (10-15 minutes). Give your students thefollowing instructions: “From the photographs on
display, select the one that best illustrates or symbolizes
your feelings or ideas about evolution. Look at the
pictures and give some thought to their selection
process. After selecting a photograph, return to yourdesk and write down your answers to the following
questions (listed on the Picture This handout). Use a
glue stick to attach the photograph to your handout.
Questions from Picture This Handout
1. Every picture deserves a title. Select a title, or a caption, for the picture you’ve chosen.

2. There were many pictures from which to choose.
Why did this picture appeal to you? (Please write atleast two sentences.)
3. How does the picture you’ve chosen reflect or symbolize your thoughts about evolution? (Please write atleast three sentences.)
Listening. Now comes the opportunity for everyone’s
voice to be heard—and for everyone to listen to theirclassmates’ ideas and opinions. Move around the class,asking every student to briefly describe the picture they
selected and to read one of their answers aloud—anyanswer they feel most comfortable reading. Acknowledge each student positively—with a smile, or a “Thankyou,” or “Good work.” A simple, friendly, and nonjudgmental acknowledgement of each student’s effort toexpress herself is what you will aim for.
Remember that this is a chance for your students toarticulate ideas that may be rather difficult to express.
Most students will be at the beginning of the process oflearning about this complicated scientific concept; they
are engaging the topic and readying themselves to learn
about it. At the end, you may need to gently correct anyof your students’ misunderstandings about the scienceand its history that were revealed during the exercise;but do this in a general way, without pinpointing a particular student’s error. At the very end, praise all yourstudents for their good listening.

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127

PICTURE THIS: EVOLUTION

Paste or tape your picture here.
If your picture is large, you canplace it on the back of this paper.

1. Every picture deserves a title. Select a title, or a caption, for the picture you’vechosen.

2. There were many pictures from which to choose. Why did this picture appeal toyou? (Please write at least two sentences.)

3. How does the picture you’ve chosen reflect or symbolize your thoughts about
evolution? (Please write at least three sentences.)

128© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

Darwin, the WriterWe cannot overestimate the importance of
the written word to the development of thescience of evolution and to its dissemination
among a wide public of scientists and non-scientists
that continues to grow. The first edition — 1,250 copies— of On the Origin of Species sold out entirely in 1859.
New editions quickly followed. In the years since, therhetorical style in which Darwin made his groundbreaking arguments has has been an important reason for thisbook’s continuing interest and influence.
That Darwin’s work as a writer is entwined with hiswork as a scientist is important to know. The long listof his works published in his lifetime, beginning withhis account of the five-year voyage that took him to the
Galapagos Islands off South America (Voyage of the
Beagle, 1839), attests to his productivity as a writer.
The nature of many of his publications suggests his
wish to convey newsof his findings and todescribe his life as ascientist in languagethat could be understoodand appreciated by bothexpert and lay audiences.
A letter to his publisher
indicates the breadth of
the audience Darwin envisioned for On the Origin
of Species. He wrote: “Myvolume cannot be mere
light reading, & some parts
must be dry & some rather
abstruse; yet as far I canjudge perhaps very falsely, it will be interesting to all(& they are many) who care for the curious problem of
the origin of all animate forms” (Darwin, 1859, April 2).
While some parts may indeed be heavy going, Darwin’s
book as a whole is written to engage and inform a fairly
wide audience (who might be interested and knowledgeable, but not necessarily expert in the field). On the Origin
of Species was, in some senses, in its time, a work of
popular science not unlike those we may find at Amazon.
com or frequently on best-seller lists today.
In his autobiography, Darwin describes in some detailthe creation and reception of a number of his publications, including his magnum opus:

In September 1858 I set to work by the strong advice of[Charles] Lyell and [Joseph Dalton] Hooker to preparea volume on the transmutation of species, but was often
interrupted by ill-health. [...] It cost me thirteen months
and ten days’ hard labour. It was published under the title of the Origin of Species, in November 1859. Thoughconsiderably added to and corrected in the later editions, it has remained substantially the same book.
It is no doubt the chief work of my life. It was from thefirst highly successful. The first small edition of 1250
copies was sold on the day of publication, and a second
edition of 3000 copies soon afterwards. Sixteen thousand copies have now (1876) been sold in England andconsidering how stiff a book it is, this is a large sale. It
has been translated into almost every European tongue,even into such languages as Spanish, Bohemian,
Polish, and Russian. […] Evenan essay in Hebrew has appearedon it, showing that the theory is
contained in the Old Testament!
The reviews were very numerous;
for a time I collected all that appeared on the Origin and on myrelated books, and these amount(excluding newspaper reviews)
to 265; but after a time I gaveup the attempt in despair. (Darwin, 1993, pp. 122-123)
Though Darwin was modest in
his assessment of his facility as a writer, he nonetheless cared to do his best. It isclear that he worked hard to be a good writer. English
teachers in particular will appreciate Darwin’s methods:
his use of outlines at the “pre-writing” stage, his quickroughing in of early drafts, and his subsequent work topare, correct, and polish.
I have as much difficulty as ever in expressing myself
clearly and concisely; and this difficulty has caused me
a very great loss of time; but it has had the compensating advantage of forcing me to think long and intently
about every sentence, and thus I have been often led tosee errors in reasoning and in my own observations or
those of others.
There seems to be a sort of fatality in my mind leading© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

129me to put at first my statement and proposition in awrong or awkward form. Formerly I used to think about
my sentences before writing them down; but for several
years I have found that it saves time to scribble in a vile
hand whole pages as quickly as I possibly can, contracting half the words; and then correct deliberately.
Sentences thus scribbled down are often better ones
than I could have written deliberately.
Having said this much about my manner of writing, I
will add that with my larger books I spend a good dealof time over the general arrangement of the matter. I
first make the rudest outline in two or three pages, andthen a larger one in several pages, a few words or onword standing for a whole discussion or series or facts.
Each of these headings is again enlarged and oftentransformed before I begin to write in extenso [“at fulllength”]. (Darwin, 1993, p. 137)

The result of Darwin’s effort is prose that is typicallylucid and sometimes beautiful. In A Short History ofEnglish Literature, Ifor Evans writes, “Charles Darwin
would have disclaimed any right to be considered as aliterary artist, yet the clarity of his style, and the very
quietness with which he presents his profound conclusions, give to much of his work the qualities of art”
(Evans, 1940, 1961, p. 220).
Because Darwin took pains with his writing, even theparagraph that ends the first edition of On the Origin ofSpecies — a passage considered by many a reader to beboth graceful and effective — did not escape modification. Darwin continued to tweak the text in subsequent
editions: “an entangled bank” thus became “a tangledbank,” for instance, and “external” was deleted before “conditions of life.” He also made the significant
addition of the phrase “by the Creator” in the second
edition.

TEXTS OF THE LAST PARAGRAPHS IN THE FIRST AND SECOND EDITIONSFirst edition (published on November 24th, 1859)

Second edition (published on January 7th, 1860)

It is interesting to contemplate an entangled bank,clothed with many plants of many kinds, with birds
singing on the bushes, with various insects flitting
about, and with worms crawling through the damp
earth, and to reflect that these elaborately constructed
forms, so different from each other, and dependent
upon each other in so complex a manner, have all
been produced by laws acting around us. These laws,
taken in the largest sense, being Growth with Reproduction; Inheritance, which is almost implied byreproduction; Variability from the indirect and direct
action of the external conditions of life, and from use
and disuse; a Ratio of Increase so high as to lead toa Struggle for Life, and as a consequence to Natural
Selection, entailing Divergence of Character andthe Extinction of less-improved forms. Thus, fromthe war of nature, from famine and death, the most
exalted object which we are capable of conceiving,
namely, the production of the higher animals, directly
follows. There is grandeur in this view of life, with its
several powers, having been originally breathed intoa few forms or into one; and that, whilst this planet
has gone cycling on according to the fixed laws ofgravity, from so simple a beginning endless forms
most beautiful and most wonderful have been, andare being, evolved.

It is interesting to contemplate an entangled bank,clothed with many plants of many kinds, with birds
singing on the bushes, with various insects flitting
about, and with worms crawling through the damp
earth, and to reflect that these elaborately constructed
forms, so different from each other, and dependent
upon each other in so complex a manner, have all
been produced by laws acting around us. These laws,
taken in the largest sense, being Growth with Reproduction; Inheritance, which is almost implied byreproduction; Variability from the indirect and direct
action of the external conditions of life, and from use
and disuse; a Ratio of Increase so high as to lead toa Struggle for Life, and as a consequence to Natural
Selection, entailing Divergence of Character andthe Extinction of less-improved forms. Thus, fromthe war of nature, from famine and death, the most
exalted object which we are capable of conceiving,
namely, the production of the higher animals, directly
follows. There is grandeur in this view of life, with
its several powers, having been originally breathedby the Creator into a few forms or into one; and that,whilst this planet has gone cycling on according to
the fixed laws of gravity, from so simple a beginning
endless forms most beautiful and most wonderfulhave been, and are being, evolved.

130© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

DISCUSSION QUESTIONS, GUIDED READING, AND ACTIVITIESFOR CHARLES DARWIN’S ON THE ORIGIN OF SPECIES
Subjects: English, Science

OVERVIEW
Teachers want their students to develop the patienceand focus needed to carry out tasks that take place inmore than one class period, such as following all thesteps in a lengthy experimental process or attentively
reading a whole novel. But asking students to pay very
close attention while reading a short piece of writing—apoem, a newspaper article, or a passage from a longer
work—can in a manageable timeframe help them to develop their analytical skills, their understanding of how
language works, and their appreciation for what makes
writing compelling and useful. If the passage they are
asked to read with close attention is written well, is richin ideas, and has historical or literary significance, somuch the better!
Depending upon the teacher’s guiding questions, thewell-known last paragraph of Charles Darwin’s On theOrigin of Species can provide a focus for analyticalreading in a biology class or an English class.

RESOURCES• Handout (attached) — The last paragraph of Charles
Darwin’s On the Origin of Species• Optional — On the Origin of Species by Charles
DarwinCLASS DISCUSSION
Listed below are a number of questions that you can use
to guide your students’ reading and analysis of this passage. Some questions may be more suitable for use inyour lesson plan than others. Choose the questions thatwill meet the needs of your class.

An 1871 caricature in Hornet magazine portraying Darwin as an ape.
was written. Discussion of this passage would fit into aunit on Victorian literature; as an introduction to a studyof an evolution-themed literary work (see “Additional
Activities for English Classrooms”); or as a model for
analysis of rhetorical strategies in other works. If yourstudents can also connect the passage with what they
have learned in their science classes, you will havehelped them build a useful bridge from discipline todiscipline.

GUIDED READING• If you are a biology teacher, you may wish to ask
questions that will encourage your students to draw onknowledge they have gained in your class or in theirprevious science courses. While introducing them toa significant work in the scientific literature, such a
discussion will also help your students see the centralityof biological evolution to any understanding of modern
biology.

You can lead the whole class in a discussion of thequestions you have selected. Or you can divide yourclass into four groups. Assign one sentence to eachgroup. Ask each group to answer all or some of thequestions about the sentence assigned to them. Eachgroup then reports their answers to the class as a whole.

• If you are an English teacher, you may wish to focus
on questions that call on your students to think of
the style of the passage, its vocabulary, the rhetorical
techniques employed, and the literary period in which it

It is interesting to contemplate an entangled bank,clothed with many plants of many kinds, with birds
singing on the bushes, with various insects flitting about, and with worms crawling through the

1. The First Sentence© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

131damp earth, and to reflect that these elaborately
constructed forms, so different from each other, anddependent upon each other in so complex a manner,have all been produced by laws acting around us.
• Darwin begins his concluding paragraph with a very
long sentence in which he describes “an entangledbank.” Have you been on the bank of a river or beside acreek? What did you see there? What would you expect
to see there?
• List the organisms Darwin describes as inhabiting theentangled bank. (He mentions “plants” and “bushes,”“birds,” and “insects” and “worms.” Perhaps we can also
include the people contemplating the bank — the “us” at
the end of the sentence — in the list of organisms.)• What verbs does Darwin use to describe the organisms
on the bank? (The plants “clothe” the bank, the birds“sing,” the insects “flit,” and the worms “crawl.”) Whatwould the sentence be like if you removed those verbs?
Would the sentence be a good one? What would thesentence be like if you removed the organisms? Why
does Darwin include all of these organisms?
• Can you envision the environment or ecosystem thatDarwin describes in this sentence?
• Can you draw (or find) a picture that matches Darwin’s description of this bank?
• Why does Darwin include these words in this sentence: “entangled,” “elaborately,” “complex”? (Perhaps
they reflect the complexities of the world around us, theinterconnections among organisms and their environments, or the complexity of the ideas Darwin’s bookhas discussed.)• What have you learned in biology that helps you
understand what Darwin is referring to when he uses
these phrases:
a. “elaborately constructed forms” (biologicaldevelopment);b. “dependent upon each other” (interrelationships
among organisms and their environments);
c. “produced by laws” (genetics, biological evolution; also see the second sentence of the paragraph)?
• Why does Darwin include these words in the opening
sentence of this paragraph: “interesting,” “contemplate,”and “reflect”? What is he asking his reader to do? Is Darwin saying something about his own thought processes?

132• Why do you suppose Darwin chose to begin thisimportant paragraph—the final impression he is leavingwith his readers—with a somewhat detailed descriptionof the “entangled bank”?
• Why does this sentence end with the words “aroundus”?
2. The Second Sentence
These laws, taken in the largest sense, being
Growth with Reproduction; Inheritance, which isalmost implied by reproduction; Variability fromthe indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of
Increase so high as to lead to a Struggle for Life,and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction ofless-improved forms.
• What does Darwin do in this long second sentence? Ishe writing a summary of his book’s main points?
• How does Darwin punctuate the sentence? (There arethree semi-colons, which serve to connect four independent clauses. A semi-colon is also used in the fourth
sentence. You might ask your students to try to use thispunctuation mark in their next writing assignment, or tolook for it in their next reading assignment.)• What have you learned in biology that helps you know
something about the processes that Darwin briefly mentions in this sentence:a. “Growth with Reproduction” (biological development);b. “Inheritance, which is almost implied by reproduction” (genetic inheritance);c. “Variability from the indirect and direct action of
the external conditions of life, and from use anddisuse.” (biological adaptation);d. “A Ratio of Increase so high as to lead to a
Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Characterand the Extinction of less-improved forms.”(biological adaptation)?
3. The Third Sentence
Thus, from the war of nature, from famine anddeath, the most exalted object which we arecapable of conceiving, namely, the productionof the higher animals, directly follows.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

• This is the shortest sentence in the paragraph, and yet
it is very powerful. What do you think of Darwin’s useof these dramatic words: “war,” “famine,” “death,” and“exalted”? When you read or hear these words, what
specific things do you personally think about? Whatmeaning do these words have for you?
• To what is Darwin referring when he uses the phrases“war of nature” and “famine and death”? (A brief description of the inspiration Darwin drew from Malthus’s
writing on population may be useful here. Thomas
Robert Malthus [1766-1834] posited that, through calamitous events such as famine or outbreak of disease,
populations were stabilized so that they would not
outpace available resources.)• To what is Darwin referring when he uses the phrases“exalted object” and “higher animals”? Could he bereferring to his readers—to us?
• What have you learned in biology that helps you
understand this sentence?
4. The Fourth Sentence of the Paragraph — and theLast Sentence of the Book
There is grandeur in this view of life, with its
several powers, having been originally breathedby the Creator into a few forms or into one; andthat, whilst this planet has gone cycling on according to the fixed laws of gravity, from so simple abeginning endless forms most beautiful and mostwonderful have been, and are being, evolved.

changing in form. Further we must suppose that
there is a power always intently watching eachslight accidental alteration in the transparent layers; and carefully selecting each alteration which,under varied circumstances, may in any way, orin any degree, tend to produce a distincter image.
We must suppose each new state of the instrument
to be multiplied by the million; and each to bepreserved till a better be produced, and then theold ones to be destroyed. In living bodies, variation will cause the slight alterations, generation
will multiply them almost infinitely, and natural
selection will pick out with unerring skill each
improvement. Let this process go on for millions on
millions of years; and during each year on millions of individuals of many kinds; and may we notbelieve that a living optical instrument might thus
be formed as superior to one of glass, as the worksof the Creator are to those of man?
A search of the many on-line texts of The Origin ofSpecies will reveal other instances of Darwin’s use of
the word “Creator.”)• What contrast is Darwin drawing in the first and lastsentences of this paragraph? In the last sentence hementions “so simple a beginning.” How does this relate
to the first sentence of the paragraph, in which he used
the words “entangled,” “elaborately,” and “complex”?
Is he referring to changes occurring in nature over time?
Is Darwin contrasting the entangled bank in the present
with a primordial scene in the long-distant past?

• Which three words did not appear in the first edition,
but were added to the second edition? (“by the Creator”). Why might Darwin have included these words?

• Why does Darwin include these words in the final sentence of his book: “grandeur,” “beautiful,” and “wonderful”? What is he asking his reader to think about?
Is Darwin saying something about his own thoughtprocesses?

• Did references to a “Creator” appear in other parts ofthe first edition? (Yes. For example, in Chapter 6, in thesection entitled “Organs of the extreme perfection andcomplication,” Darwin writes about the development of
the eye:• What does Darwin mean by the phrase “this viewof life”? Can you put his view of life into your own
words?

Have we any right to assume that the Creator
works by intellectual powers like those of man? If
we must compare the eye to an optical instrument,
we ought in imagination to take a thick layer oftransparent tissue, with a nerve sensitive to lightbeneath, and then suppose every part of this layer
to be continually changing slowly in density, so as
to separate into layers of different densities andthicknesses, placed at different distances from eachother, and with the surfaces of each layer slowly• What is your opinion of the last sentence of On theOrigin of Species?
• What is your opinion of the final paragraph of On theOrigin of Species? What did you learn from it that you
did not know before? (Answers might include opinions
about Darwin himself, about the book, or about the science of biological evolution.)© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

133ADDITIONAL ACTIVITIES FOR ENGLISH CLASSROOMS• After your class analyzes the last paragraph of On theOrigin of Species, ask each student to find another shortpassage of non-fiction writing that has also had an important impact on humankind (e.g., the Preamble to theUnited States Constitution or a portion of Martin LutherKing Jr.’s “I Have a Dream” speech). Ask each student
to consider where the passage’s power lies: the beautyof the language, the strength of the argument, the historical moment it addressed, or other factors. You mightwish to limit the assignment by genre, time frame, or
nationality. Ask your students to explain their choices.
• Alternatively, you may wish to ask your students tofind and analyze a short passage of writing that has
had a powerful or important impact on them personally (e.g., the passage from a book they like, part of aletter or message they may have received, the lyrics of asong). Ask your students to explain their choices. Why
has the author of each piece of writing succeeded inreaching his or her audience?
• Discussion of the last paragraph of On the Origin ofSpecies would serve as a useful introduction to a unit onother evolution-themed literary works. We suggest several
texts that we know work well in secondary classrooms:
a. Charles Darwin’s Autobiography. Darwin’s
Autobiography, prepared by one of his sons for
publication several years after Darwin’s death,
was written primarily for a readership of family members — his children andgrandchildren. It is an accessible
book that with surprising openness and charm provides insights
into Darwin’s youth and gradualdevelopment from unfocused
student (more interested in outdoor
sport, he was considered “a very ordinary boy,rather below the common standard in intellect”)
to influential scientist (Darwin, 1958, 1993, p.
28). Readers seeking to understand more about
Darwin’s childhood, family, and marriage, his life
aboard the Beagle, his religious beliefs, and his
career will find information about these topics inthis short book. While the whole book has been
assigned successfully to secondary students, you
may prefer to make selections among the chapters, or perhaps assign chapters to groups of students. Selections from this book may be assigned
as readings in an upper-level biology class, orthey may be assigned during a unit on autobiography or memoir in an upper-level English class.

134

b. The Time Machine. H. G. Wells, a pioneer inthe science fiction, called this, his first book, a“scientific romance.” Having been a student ofT. H. Huxley (a vocal defender of evolution,
Huxley became known as “Darwin’s Bulldog”) and also a teacherof biology, Wells was well able toexplore the “what ifs?” suggestedby the swirl of ideas around evolutionary biology in the VictorianAge. The Time Machine (1895)
follows the adventures of a scientist and inventor (called “The Time Traveller”) who builds
a device that hurtles him forward along evolution’s timeline. Arriving in the year 802,701,
he encounters the strange life ways of the Eloi
and the Morlocks, species that are humans’
evolutionary descendents. The Time Machine isa novella, and therefore short enough to becomea manageable reading assignment. In addition,
a number of movies have been based on The
Time Machine. We recommend the most recent,which starred Guy Pearce and Samantha Mumbain 2002. Though some liberties are taken withthe plot, there is a useful emphasis on science,
including evolution. There is even a futuristic
librarian who discusses time travel as theme inliterature. The special effects in this version willprobably be more plausible to high school audiences today than those of George Pal’s generally
well-regarded effort of 1960.
c. Inherit the Wind. Though it takes some liberties
with the facts (adding a love interest where there
was none, for instance), this drama by Jerome
Lawrence and Robert E. Lee is recognizably
based on the Scopes “Monkey
Trial.” The play is set in a smallSouthern town patterned on
Dayton, Tennessee, where John T.
Scopes (Bertram T. Cates in theplay), was charged with breaking
a law recently enacted to prohibit
the teaching of evolution in the state’s publicschools. Though the Scopes trial was short-lived(lasting July 10-21, 1925), it generated national
interest at the time, in large part because of thefamous men representing each side in the dispute. Clarence Darrow (Henry Drummond in theplay) was a famed criminal attorney who steppedin for the defense; William Jennings Bryan(Matthew Harrison Brady), a leading politician,© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

represented the prosecution. Both men were outstanding orators, and their dramatized rhetoricaltangle ranges over science’s impact on many facets of society: education, law, religion, politics,
the press. Inherit the Wind was first produced in
1955 on Broadway. Several film versions havesince been made, with the best considered to be
the 1961 production, which features Spencer
Tracy as Drummond.
d. Cosmicomics. Italo Calvino’s Cosmicomics(1965) is rather more abstract than the otherworks mentioned here. First published in Italian, this collection of short stories follows theadventures of beings in deep time
— well before language, before
dinosaurs, before vertebrae, before
colors. While the whole bookhas been assigned successfully tosecondary students, selected stories may serve as more accessible
assignments. In particular, we recommend “TheAquatic Uncle,” which tells of the coelacanth,who prefers to stay in the water while his fellows
move to the land. This story can be accompanied
by information about the surprising discovery ofliving coelacanth off the coast of southern Africa
in 1938, though this fish had been assumed tohave become extinct tens of millions of years
before. Students can even go online to view photographs and video clips of living coelacanths—
large (reaching five feet in length), blue fish thatexisted in the time of the dinosaurs and also exist
in our time, too.

BIBLIOGRAPHY
Barlow, N. (Ed.), & C. Darwin (1993). The autobiography of Charles Darwin. New York, NY: W. W. Norton.
Darwin, C. (2003). On the origin of species: A facsimileof the first edition. Cambridge, Mass.: Harvard University
Press.
Darwin, C. (1998). The origin of species. New York,
N.Y.: Oxford University Press.
Darwin, D. (1859, April 2). To John Murray [Letter].
The Darwin Correspondence Online Database.
Retrieved May 2, 2006, from http://darwin.lib.cam.
ac.uk/per;/nav?pclass=letter;pkey=2445.
Evans, I. (1961). A short history of English literature.
Harmondsworth, Middlesex: Penguin Books.

e. Evolution in the news. Because biologicalevolution continues to spur discussion in publicforums, any number of news stories, opinioneditorials, letters to editors,
and web-site content related tothis topic may serve as current,
useful for texts for analysis.
A comparison of such a text with what yourstudents have discovered in reading the lastparagraph of On the Origin of Species may be avaluable exercise.

© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu

135THE LAST PARAGRAPH OF CHARLES DARWIN’S ON THE ORIGIN OF SPECIESFirst edition (published on November 24th, 1859)

Second edition (published on January 7th, 1860)

It is interesting to contemplate an entangled bank,clothed with many plants of many kinds, with birds
singing on the bushes, with various insects flitting
about, and with worms crawling through the damp
earth, and to reflect that these elaborately constructed
forms, so different from each other, and dependent
upon each other in so complex a manner, have all
been produced by laws acting around us. These laws,
taken in the largest sense, being Growth with Reproduction; Inheritance, which is almost implied byreproduction; Variability from the indirect and direct
action of the external conditions of life, and from use
and disuse; a Ratio of Increase so high as to lead toa Struggle for Life, and as a consequence to Natural
Selection, entailing Divergence of Character andthe Extinction of less-improved forms. Thus, fromthe war of nature, from famine and death, the most
exalted object which we are capable of conceiving,
namely, the production of the higher animals, directly
follows. There is grandeur in this view of life, with its
several powers, having been originally breathed intoa few forms or into one; and that, whilst this planet
has gone cycling on according to the fixed laws ofgravity, from so simple a beginning endless forms
most beautiful and most wonderful have been, andare being, evolved.

It is interesting to contemplate an entangled bank,clothed with many plants of many kinds, with birds
singing on the bushes, with various insects flitting
about, and with worms crawling through the damp
earth, and to reflect that these elaborately constructed
forms, so different from each other, and dependent
upon each other in so complex a manner, have all
been produced by laws acting around us. These laws,
taken in the largest sense, being Growth with Reproduction; Inheritance, which is almost implied byreproduction; Variability from the indirect and direct
action of the external conditions of life, and from use
and disuse; a Ratio of Increase so high as to lead toa Struggle for Life, and as a consequence to Natural
Selection, entailing Divergence of Character andthe Extinction of less-improved forms. Thus, fromthe war of nature, from famine and death, the most
exalted object which we are capable of conceiving,
namely, the production of the higher animals, directly
follows. There is grandeur in this view of life, with
its several powers, having been originally breathedby the Creator into a few forms or into one; and that,whilst this planet has gone cycling on according to
the fixed laws of gravity, from so simple a beginning
endless forms most beautiful and most wonderfulhave been, and are being, evolved.

Bibliography
Darwin, C. (2003). On the origin of species: A facsimile of the first edition. Cambridge, Mass.: Harvard University
Press.
Darwin, C. (1998). The origin of species. New York, N.Y.: Oxford University Press.

136© DESTINY - UNC-CHAPEL HILL - CB# 3280 - Chapel Hill, NC 27599-(919) 843-9036 - www.destiny.unc.edu