bluuebunny/crossref_metadata_2025 huggingface dataset:
Gastrotricha
Authors: Boaden Patrick JS
Published: September 2006

The Gastrotricha are meiofaunal aschelminthes mostly occurring in marine sands and in lentic freshwaters.
Cycliophora
Authors: Kristensen Reinhardt Møbjerg
Published: September 2006

The cycliophorans are the recently discovered group of microscopic marine animals with an asexual and sexual life cycle. The only described species
Symbion pandora
lives on the mouth appendages of marine lobsters and have so far only been found in the Northern hemisphere. The phylogenetic position in the Animal Kingdom is still uncertain. Cycliophorans have been considered a sister group to Entoprocta and Ectoprocta or Rotifera and Acanthocephala.
Mollusca (Molluscs)
Authors: Haszprunar Gerhard
Published: September 2006

Mollusca are bilateral (or secondarily asymmetrical) coelomate Protostomia with spiral cleavage and mostly a (often modified) trochophore‐like larva. Most species are provided with spicule or shell (plates), a mantle cavity with gills, a ciliary or muscular gliding sole (foot), a visceral portion with heart and excretory organs and alimentary tract with rasping tongue (radula).
Sipuncula (Unsegmented Marine Worms)
Authors: Cutler Edward B
Published: September 2006

Sipuncula is a phylum of unsegmented marine worms with a retractable introvert and a gut that is wound back on itself to an anus at the anterior end of the trunk.
Trilobita (Trilobites)
Authors: Clarkson Euan NK
Published: September 2006

Trilobites are extinct marine arthropods in which the body is divided transversely into a head (cephalon), a thorax of articulated segments, and a tail (pygidium). The body is also divided longitudinally into a raised axis and two lateral lobes. Mature individuals range from about 1 mm in length to 700 mm.
Crustacea (Crustaceans)
Authors: Blackstone Neil W
Published: September 2006

The Crustacea is a subphylum of arthropods defined by the nauplius larva, two pairs of antennae, and biramous second antennae.
Phoronida
Authors: Emig Christian C
Published: September 2006

The Phoronida, divided into two genera and 10 species, is a small marine group, which belongs to the phylum Lophophorata.
Chaetognatha (Arrow Worms)
Authors: Bone Quentin
Published: September 2006

Chaetognaths are elongate bilaterally symmetrical marine animals, ranging from 0.2 to 12 cm long. They have a distinct head bearing grasping spines, and a tail fin together with one or two paired fins. The bipartite body and head contain powerful rapidly contracting muscles, but apart from gut and gonads, internal organs are absent; there is no heart or blood system.
Geological Time: Dating Techniques
Authors: Prothero Donald R
Published: September 2006

Numerical dating (‘absolute dating’) of geological events allows us to place time estimates on geological and biological phenomena of the past. A number of techniques are used, most of which use the process of radioactive decay as a clock. From the latest dates, we have discovered that many evolutionary processes and events took place either much faster or much more slowly than previously imagined.
International Time Scale
Authors: Berggren William A
Published: September 2006

An ITS is a calendar of magnetic reversals and palaeontological events. The elements of an ITS consist of: (1) a Global Polarity Time Scale (GPTS) based on distances between magnetic anomalies on the sea floor; (2) analytically precise radioisotopic ages used to calibrate the GPTS; (3) precise magnetobiostratigraphic correlations from which a biochronology is derived (including the correct correlation between magnetozones and sea floor anomalies).
Fossils and Fossilization
Authors: Brett Carlton E
Published: September 2006

The study of fossil preservation – taphonomy – reveals biases of the fossil record and also provides insights into depositional rates and processes.
Exceptional Preservation
Authors: Gabbott Sarah E
Published: September 2006

Exceptionally preserved fossils are rare but are extremely important in reconstructing past life because they record details of an organism's soft tissues that are usually rapidly destroyed postmortem. Experiments on the processes of fossilization have enhanced our understanding of the biases inherent in the fossil record and allow better interpretation of morphology.
Burgess Shale
Authors: Collins Desmond H
Published: September 2006

In the Burgess Shale are preserved in exquisite detail complete communities of invertebrates that lived on the seafloor 505 million years ago, soon after the Cambrian evolutionary explosion. Burgess Shale fossils are extraordinarily important for the light they shed on early animal life and its subsequent evolution.
Rhynie Chert
Authors: Trewin Nigel H
Published: September 2006

The Rhynie chert was deposited by hot‐springs and contains exceptionally well preserved Early Devonian (
c
. 400 Ma) fossil plants and arthropods. The biota comprises the oldest well preserved terrestrial ecosystem on Earth, and the primitive terrestrial plants form the cornerstone of palaeobotany.
Solnhofen
Authors: Kemp Richard Angus
Published: September 2006

Solnhofen is an Upper Jurassic limestone found in Germany which yields diverse and exceptionally well‐preserved animal and plant macrofossils.
Palaeoenvironments
Authors: Aberhan Martin
Published: September 2006

Palaeoenvironments are depositional environments of the geological past. Palaeoenvironmental reconstructions are based on the combined evidence from physical sedimentology and the fossil content.
Earth: Changes Through Time
Authors: Prothero Donald R
Published: September 2006

Over the past 4600 million years since its formation, the Earth has undergone many changes. From a barren planet with a molten surface constantly churned by meteorites and volcanoes, and no free oxygen in its atmosphere, the Earth has evolved into a planet with large slow‐moving continents covered in vegetation that provides an oxygen‐rich atmosphere.
Sea Level Change
Authors: Prothero Donald R
Published: September 2006

The level of the oceans has risen and fallen many times in the geological past.
Morphology and Disparity through Time
Authors: Kaplan Peter
Published: September 2006

Disparity refers to the extent and statistical structure of the diversity of form among a set of taxa, measured in terms of a morphospace they co‐occupy. Disparity provides an important and distinct perspective on biodiversity, as shown by comparisons between taxonomic and morphological diversity histories of individual clades.
Eukaryotes and Multicells: Origin
Authors: Waggoner Ben
Published: September 2006

Among the most important evolutionary events of all time are the origins of eukaryotic cells and of multicellularity. Both the evolution of eukaryotes and the origins of multicellularity (convergently evolved in numerous taxa) can be studied using insights from both palaeontology and molecular biology.
Cambrian Radiation
Authors: Valentine James W
Published: September 2006

It is consistent with the fossil record that all living phyla had evolved by the end of Early Cambrian time, over half a billion years ago. Many phyla first appear as marine fossils during a 10‐million‐year period in the Early Cambrian known as the Cambrian explosion, and radiated rapidly to produce marine communities analogous to those of today.
Human Evolution: Early Radiations
Authors: Wood Bernard A
Published: September 2006

Fossil evidence suggests that African ancestors exclusively ancestral to modern humans (such as the genera
Ardipithecus
,
Australopithecus
and
Paranthropus
) had emerged by at least 4.5 million years ago, and subsequently diversified.
Homo habilis
and
Homo rudolfensis
are adaptively and cladistically closer to this early hominin radiation than they are to later
Homo
taxa.
Biotic Response to Climatic Change
Authors: Brenchley Patrick John
Published: September 2006

The present distribution of organisms is broadly related to climate. Past changes in climate, on both long‐ and short‐term time scales, have commonly resulted in shifts in biotic distribution, but in extreme cases they have caused major episodes of extinction.
Extinction: Late Ordovician Mass Extinction
Authors: Brenchley Patrick John
Published: September 2006

The Late Ordovician mass extinction was one of the five outstanding mass extinctions in Earth history. It was caused by environmental changes linked to exceptionally large climatic shifts and resulted in a massive elimination of species, but no major lasting changes in ecological structure or evolutionary direction.
Extinction: End‐Permian Mass Extinction
Authors: Erwin Douglas H
Published: September 2006

The end‐Permian mass extinction was the most pervasive biotic crisis in the history of life. About 80% of marine species and some 70% of land species became extinct, probably in two pulses separated by about 10 million years.
Modern Extinction
Authors: Boulter M
Published: September 2006

Since the last ice age the number of individuals of many species of animals and plants have declined, often to zero. The losses reflect environmental changes caused both naturally and by humans.
Biotic Recoveries after Extinction
Authors: Erwin Douglas H
Published: September 2006

Ecosystem recovery following mass extinctions is often complex, but data suggest a model of initial appearance of opportunistic forms, followed by reappearance of more specialized survivors and diversification of new forms.
Evolution of Development
Authors: Abouheif Ehab , Wray Gregory A
Published: September 2006

The field of evolutionary developmental biology provides a framework with which to elucidate the ‘black box’ that exists between evolution of the genotype and phenotype by focusing the attention of researchers on the way in which genes and developmental processes evolve to give rise to morphological diversity.
Molecular Clocks
Authors: Martin Andrew Peter
Published: September 2006

Molecules such as proteins and DNA evolve over time as a consequence of the fixation of mutations to DNA. Molecular evolution has been shown to be approximately constant across species, a phenomenon known as the molecular clock.
Plant Plasma Membrane
Authors: Larsson Christer , Sommarin Marianne , Pical Christophe , Kjellbom Per , Widell Susanne
Published: September 2006

The plasma membrane of the cell encloses the cell contents and
acts as a barrier between the cell and its environment. The plasma membrane
allows the exchange of ions and solutes with the rest of the organism and its
surroundings, and plays an important role in plant development, pathogen
resistance and frost‐hardiness.
Plant Endoplasmic Reticulum
Authors: Denecke Jurgen
Published: September 2006

The plant endoplasmic reticulum is responsible for the synthesis
and often storage of a large group of proteins and lipids that enter the
secretory pathway. This multifunctional organelle, which also represents one
of the calcium storage compartments in plant cells, has currently received
considerable interest in the research community because of features unique to
plants that make it particularly interesting for biotechnology.
Plant Vacuoles
Authors: Neuhaus Jean‐Marc , Martinoia Enrico
Published: September 2006

Most plant cells contain one or several vacuoles, which may
occupy up to 95% of the cellular space. The vacuoles often appear empty
under a light microscope (hence their name), except when they contain pigments
or precipitated substances. The vacuole is delimited from the cytosol by the
vacuolar membrane, which is also called tonoplast.
Plant Chloroplasts and Other Plastids
Authors: Flügge Ulf‐Ingo
Published: September 2006

Plastids are a group of organelles that are characteristic of plant cells. They are able to perform many specialized functions that are essential for plant growth and development, such as photosynthesis, nitrogen assimilation, the synthesis of amino acids and of fatty acids, storage of carbohydrates and lipids or the formation of colours in some fruits and flowers.
Plant Cell Walls
Authors: Fry Stephen C
Published: September 2006

The cell wall, as the outer coat of a plant cell, controls cell expansion, gives plant cells their characteristic shapes, and provides protection. Cellulose is only one of many polysaccharides and other polymers of the higher plant cell wall; some of these polymers undergo chemical reactions in the walls of living cells.
Plant Cell Walls: Economic Significance
Authors: BeMiller James N
Published: September 2006

Plant cell walls are composed of polysaccharides and, in the case of higher plants, lignin. The economic significance of plant cell walls arises largely from three types of uses: (1) use of whole tissues or slightly processed tissues whose constituents are primarily cell‐wall components (wood and other plant fibres); (2) use of delignified and extracted tissues (pulp); (3) use of extracted, and in some cases chemically modified, water‐soluble cell‐wall polysaccharides (pectins, seaweed polysaccharides, hemicelluloses). Other substances that can be extracted from plant tissues are generally extraneous to the cell wall.
Plant Mitosis, Cytokinesis and Cell Plate Formation
Authors: Cyr Richard J
Published: September 2006

Cell division in plants involves nuclear division and cell plate
formation. These two processes ensure a steady supply of new cells for the
growing and developing plant.
Turgor Pressure
Authors: Pritchard Jeremy
Published: September 2006

Hydrostatic pressure, termed turgor pressure, is generated in
plant cells because water moves by osmosis across semipermeable membranes.
Turgor plays an important part in plant growth, movement and transport.
Plant Cell Growth and Elongation
Authors: McCann Maureen C , Roberts Keith , Carpita Nicholas C
Published: September 2006

The plant cell wall is a strong material that resists expansion
when water is taken up by the protoplast; for cells to expand
irreversibly, the existing wall architecture must be loosened to permit the
insertion of newly synthesized wall polymers. Biochemical approaches have
identified changes in wall composition that occur during growth and some of
the enzymes involved in wall loosening, whilst the study of mutants is
beginning to identify genes involved in plant cell growth and elongation.
Plant Programmed Cell Death
Authors: Lam Eric , Kato Naohiro , Pontier Dominique
Published: September 2006

Programmed cell death (PCD) in higher plants is observed
throughout their development and in pathogenic infection. There is evidence of
mechanistic and morphological similarities to cell death in animals but many
fundamental questions related to plant PCD remain to be answered.
Evolutionary Ideas: Darwin
Authors: Bowler Peter J
Published: September 2006

Charles Darwin is rightly regarded as the founder of modern
evolution theory, although it is important to distinguish between his proposal
of the theory of natural selection and his role in converting the scientific
community to evolutionism. The general idea of evolution was soon accepted,
but the selection theory remained controversial until the middle of the
twentieth century.
Evolution of Genome Organization
Authors: Stephan Wolfgang
Published: September 2006

Several features of chromosomes, such as chromosome number, polyploidy and the accumulation of repetitive DNA sequences near centromeres, reflect the evolutionary forces acting on eukaryotic genomes.
Repetitive DNA: Evolution
Authors: Stephan Wolfgang , Walsh Bruce
Published: September 2006

Repetitive DNA sequences form a substantial fraction of the genomes of most eukaryotes. Far from conferring fitness benefits to their host, in most cases repetitive sequences are maintained solely by their ability to replicate within the genome.
Molecular Evolution: Introduction
Authors: Penny David
Published: September 2006

Molecular evolution studies the mechanisms leading to present day DNA and protein sequences – it is a unifying force in biology.
Variation, Within Species: Introduction
Authors: Harrison Richard M
Published: September 2006

Individuals within a species will have similar genes but will differ in phenotypic characteristics and behaviour because of slight differences in the genotype and response to environmental conditions. This was first reported by Charles Darwin and Alfred Wallace in the paper ‘On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means’ read to the Linnean Society in London on 1 July 1858.
Sexual Selection
Authors: Shykoff Jacqui A
Published: September 2006

Sexual selection was proposed by Darwin to explain the evolution of traits that do not contribute to survival or fecundity, such as the elaborate train of the peacock, the horn of the rhinoceros beetle, and the bright red belly of the stickleback. The development of such characteristics gives some individuals higher reproductive success because they achieve more matings or successful fertilizations. Sexual selection operates between individuals of the same sex as they compete for mates, and between the sexes as individual choices are made of mating partner.
Evolution: Tempo and Mode
Authors: Damuth John D
Published: September 2006

‘Tempo’ refers to the rate of evolution, the rate of phenotypic change either within lineages or expressed as averages within major taxonomic groups. ‘Mode’ refers to the pattern of evolution – whether it is continuous or episodic; whether it is primarily phyletic (within‐lineage) or proceeds mostly by lineage‐splitting; whether it shows directional trends or not; and whether it proceeds by small steps or sudden jumps.
Darwinian Medicine
Authors: Williams George C
Published: September 2006

Modern concepts of evolutionary biology can provide important insights into human vulnerability to disease and suggest ways of reducing that vulnerability and treating the diseases. They also suggest some urgently needed research.
Mutation Rates: Data
Authors: Schultz Stewart T
Published: September 2006

Estimates of mutation rates from standard methods.
Variation: Measures
Authors: Fu Yun‐Xin
Published: September 2006

Genetic variation refers to identifiable genetic differences within and between individuals. A measure of genetic variation is a summary statistic of the amount and pattern of genetic variation.
Fitness
Authors: Day Troy , Otto Sarah P
Published: September 2006

Fitness is a measure of the survival and reproductive success of an entity. This entity may be a gene, individual, group or population.
Microbial Evolution
Authors: Travisano Michael
Published: September 2006

Microbial evolution is the study of the patterns and processes that affect the dynamics of microbial diversity over time.
Speciation: Chromosomal Mechanisms
Authors: Nevo Eviatar
Published: September 2006

Chromosomal speciation is one of the major modes of the origin of new species through splitting of pre‐existing species. New species may originate by the establishment of postmating reproductive isolation through structural chromosome rearrangements, which may induce low hybrid fitness.
Selection: Frequency‐dependent
Authors: Stevens Lori
Published: September 2006

Differential survival and reproduction of organisms based on gene or genotype frequencies of other individuals in the same population is frequency‐dependent selection. Negative frequency‐dependent selection favours rare genotypes and promotes genetic variation in populations. Positive frequency‐dependent selection favours common alleles, accelerates the loss of rare alleles, and decreases genetic variation.
Coevolution: Host–Parasite
Authors: Penn Dustin J
Published: September 2006

Hosts and their parasites have an intimate and antagonistic relationship; therefore, they are expected to play important roles in influencing each other's evolution. When a host evolves a defence against a parasite, then the parasite may evolve counter‐adaptations to its host's defence. Host–parasite coevolution may have several possible outcomes, and, contrary to popular belief, does not necessarily lead to mutualism.
Cospeciation
Authors: Page Roderic DM
Published: September 2006

Cospeciation is joint speciation of both host and parasite, resulting in host and parasite phylogenies being mirror images of each other.
Mutation–Selection Balance
Authors: Spencer Hamish G
Published: September 2006

An organism's genome is continually being altered by mutations, the vast majority of which are harmful to the organism or its descendants, because they reduce the bearer's viability or fertility. Consequently, every generation, natural selection acts to weed out these deleterious mutations. The opposing processes of mutation and selection balance each other so that the frequency in a population of a deleterious mutation remains at an equilibrium value determined by the strength of selection and the frequency of mutation.
Population Structure
Authors: Wade Michael J
Published: September 2006

The ecological processes of extinction, colonization and migration in metapopulations gives rise to the unique evolutionary properties of structural populations.
Macroevolution: Overview
Authors: Levinton Jeffrey S
Published: September 2006

Macroevolution is the sum of a range of processes that explain evolutionary changes that resulted in the diversity of major body plans through geological time and at present. The field addresses the origin of major taxonomic groupings, the causes of evolutionary radiations, major biogeographic patterns, and large‐scale extinctions.
Punctuated Equilibrium and Phyletic Gradualism
Authors: Sheldon Peter R
Published: September 2006

Punctuated equilibrium and phyletic gradualism are contrasting patterns of evolution among a spectrum of patterns found in the fossil record. In punctuated equilibrium, species tend to show morphological stasis between abrupt speciation events, whereas in phyletic gradualism species undergo more continuous change.
Homology in Character Evolution
Authors: Staton Joseph L
Published: September 2006

Homology forms the basis of organization for comparative biology. Richard Owen's simple definition of homology as the ‘same organ in different animals under every variety of form and function’ takes on new complexity in light of Darwinian evolution and modern molecular biology.
Thompsonian Transformations
Authors: Horder Tim
Published: September 2006

Thompsonian transformations are a graphical method for studying the relations of the morphologies of organisms in terms of their overall patterns of modifications to their shared geometries.
Heterochrony
Authors: Horder Tim
Published: September 2006

Heterochrony is a supposedly important mechanism for macroevolutionary change based on shifts in the timing of developmental events in the embryo.
Population Genetics: Multilocus
Authors: Gavrilets Sergey
Published: September 2006

Multilocus population genetics is the study of the distribution and dynamics of genetic variation at several loci in biological populations.
Genetic Load
Authors: Davis B , Whitlock MC
Published: September 2006

Genetic load is the reduction in the mean fitness of a population relative to a population composed entirely of individuals having optimal genotypes.
Darwin's Finches
Authors: Hau Michaela , Wikelski Martin
Published: September 2006

Darwin's finches are a prime example of adaptive radiation and of evolution in action. Beak size of these equatorial bird species repeatedly changed within two decades as a response to environmental changes during El Niño conditions.
DNA Sequence Analysis
Authors: Gojobori Takashi , Wyndham Allison
Published: September 2006

Analysis of DNA sequence data can reveal biologically useful information and with the immense quantity of data now available, sequence analysis provides a valuable complement to empirical studies and is an essential part of the characterization of new proteins. Useful methodologies include searching databases, conducting sequence alignments, estimating the evolutionary or genetic distance and constructing molecular phylogenetic trees.
Molecular Evolution: Rates
Authors: Bromham Lindell D
Published: September 2006

The pace of molecular change is more clock‐like than morphological evolution, yet there is clearly variation in molecular evolution rate between biological lineages. The causes of this rate variation are still largely unknown, but may be influenced by species characteristics, population processes, and natural selection.
Molecular Clock: Testing
Authors: Kumar Sudhir , Filipski Alan J
Published: September 2006

Molecular clock tests are used to examine whether rates of molecular evolution vary significantly among taxonomic groups or phylogenetic lineages.
Codon Usage in Molecular Evolution
Authors: Grantham Richard L
Published: September 2006

In protein synthesis, succeeding amino acids are indicated by a sequence of codons in the gene. A given amino acid may be represented by up to six codons, making a choice between synonymous codons possible; this permits the creation of an evolutionary pattern of codon usages.
Genome Evolution: Overview
Authors: Walsh J Bruce
Published: September 2006

The genome is the total genetic constitution of an organism. Understanding of the structure and evolution of genomes is undergoing a revolution with ability to sequence entire genomes. A key feature in the evolution of genomes is the creation of new genes, usually by duplication.
Somatic Cell Genetics
Authors: Ruddle Frank
Published: September 2006

Somatic cell genetics make use of paragenetic mechanisms such as cell hybridization and chromosome segregation to analyse complex mammalian genomes.
Plant Tracheary Elements
Authors: Fukuda Hiroo
Published: September 2006

Formation of tracheary elements, which are constituents of vessels and tracheids, is a model of cell differentiation and programmed cell death in plants.
Vertebrate Functional Morphology and Physiology
Authors: Westneat Mark W
Published: September 2006

Functional morphology is the study of the design of tissues and organ systems, the principles of physics affecting animals, and the mechanisms of the body. Physiology is the study of how living organisms adjust to their environments and regulate critical functions at the tissue, system, cellular and molecular levels. Together the two related fields include a broad range of topics such as feeding mechanics, digestion, locomotion, muscle contraction, circulatory design, oxygen exchange and other topics focused on animal function.
Energy Cycle in Vertebrates
Authors: Weber Jean‐Michel
Published: September 2006

Vertebrates store, mobilize, transport, and use their metabolic fuel reserves to produce ATP, the universal energy currency of all living cells. Depending on the amount of ATP required, the time available to make it and the oxygen availability, ATP synthesis takes place through anaerobic glycolysis or oxidative pathways.
Vertebrate Metabolic Variation
Authors: McNab Brian K
Published: September 2006

A variety of factors contribute to the variation in energy expenditure of vertebrates, including those associated with anatomical and physiological organization as well as those reflecting differences in behaviour and conditions in the environment.
Thermoregulation in Vertebrates: Acclimation, Acclimatization and Adaptation
Authors: Speakman John R
Published: September 2006

Environments vary enormously in the thermal challenge they impose on the organisms that live in them. Some of these changes occur over very small temporal and spatial scales, and animals respond to these changes by acute modulations of their behaviour and physiology. More chronic changes in thermal environments, such as seasonal changes and latitudinal changes across the globe, require different responses. Three types of response have been recognized in both exothermic and endothermic vertebrates. These are termed acclimation, acclimatization and adaptive responses.
Respiration and Circulation in Vertebrates: Overview
Authors: Hoppeler Hans , Weibel Ewald R
Published: September 2006

Respiration provides cells with oxygen for their metabolic needs by transport of oxygen from the lungs to the tissues via the circulation of the blood. The cellular target of the oxygen is the mitochondria, where the cell's energy transduction takes place.
Circulation in Vertebrates
Authors: Farrell AP
Published: September 2006

All vertebrate animals have a circulatory system, consisting of a central pump (the heart) and a system of tubes (the vascular and lymphatic systems) through which a fluid (blood and lymph) is continuously circulated.
Ingestion in Fish
Authors: Westneat Mark W
Published: September 2006

Fishes are the largest group of vertebrates on Earth and this
diversity of species number is reflected in the wide range of ways that fishes
acquire food and the types of food that are ingested. Major topics in fish
feeding include the range of dietary habits of fishes, the diverse strategies
of capturing or ingesting food, the functional morphology of the jaws of
fishes, ecological patterns of prey acquisition, and evolutionary trends in
fish feeding biology.
Ingestion in Birds
Authors: Zweers Gart , Berkhoudt Herman
Published: September 2006

Ingestion of food and water in birds is mediated by an extremely
diverse trophic system which traces back upon only two modifications of one
single anatomical design, i.e. a kinetic, beaked skull. The mechanics of
ingestion are characterized by lower jaw depression linked to a movable upper
jaw which is highly integrated with tongue and larynx motion – though
often compromised by functional demands from drinking and vocalization –
controlled primarily by touch and taste.
Ingestion in Mammals
Authors: Wall Christine E , Smith Kathleen K
Published: September 2006

Ingestion in mammals is distinguished from that of other
vertebrates by mastication, suckling, and complex food transport and
swallowing. The teeth, cranial bones, and musculature of the head reflect
these distinguishing features.
Digestive System of Amphibians, Reptiles and Birds
Authors: Stevens C Edward
Published: September 2006

The digestive systems of amphibians, reptiles, and birds share
many characteristics with those of fish. However, the transition of amphibians
from an aquatic to a terrestrial environment, the development of endothermy in
birds, and the adoption of a wider range of diets required a number of
adaptations.
Osmoregulation by Vertebrates in Aquatic Environments
Authors: Evans David H
Published: September 2006

Because the salt concentration of the body fluids of aquatic
vertebrates differs from that of their freshwater or marine environment, they
face net movements of water and salt across their permeable membranes, most
notably the gill. Various organs and transport processes are involved in
maintaining internal consistency in the face of these potential osmotic and
salt problems.
Endocrine System in Vertebrates
Authors: Henderson Ian W
Published: September 2006

Hormones of vertebrates are classically described in the context of the principal glands that produce them and there is a generally agreed homology of the endocrine structures throughout the vertebrates. Contemporary views of hormones as key regulators take account of their sometimes ubiquitous sources, their modes of delivery, and their cellular and molecular mechanisms of action.
Sensory Systems in Vertebrates: General Overview
Authors: Braun Christopher B , Eisthen Heather L
Published: September 2006

Vertebrates have a rich complement of sensory systems that sample both external environmental conditions and the animal's own internal milieu. The nervous system uses sensory information to intiate and modify complex behaviours and to adjust physiological processes within the body.
Sensors of External Conditions in Vertebrates
Authors: Eisthen Heather L , Braun Christopher B
Published: September 2006

All animals have sensory systems for gathering information about the surrounding environment. Vertebrate animals possess many specialized sensory systems for detecting chemicals, light, vibrations in air and water, temperature and pressure on the skin, electrical signals, and even infrared and magnetic sources in the environment.
Reproduction in Fish
Authors: Hamlett William C
Published: September 2006

Reproduction in fishes generally involves external fertilization and development of yolk‐reliant offspring; however, there are a variety of live‐bearing species that utilize internal fertilization and a wide array of developmental mechanisms to support their developing young.
Reproduction in Reptiles and Birds
Authors: Smith Bonnie J
Published: September 2006

General features of reproduction in reptiles and birds as Classes rather than specific characteristics of individual Orders or Families. Similarities and differences of general reproductive physiology in reproductive behaviour of these two similar yet disparate egg‐laying groups, including brief references to courtship and rearing of young.
Comparative Vertebrate Muscle Physiology
Authors: Rome Lawrence C
Published: September 2006

Although all vertebrate skeletal twitch fibres share the same basic structure and operate by the same contractile mechanism, they are called upon to perform a host of different functions ranging from slow speed locomotion to high speed sound production. There are a number of important qualitative modifications (protein isoforms with different kinetic rates) as well as quantitative modifications (different densities of important structures) which permit this wide range of activities and form the comparative aspects of muscle physiology.
Tetrapod Limbless Locomotion
Authors: Wake Marvalee H
Published: September 2006

Many tetrapods (four‐legged animals) have lost their limbs during their evolution. They move (locomote) by specific patterns of body muscle contraction and relaxation.
Tetrapod Walking and Running
Authors: Bennett Michael B
Published: September 2006

Animals with four limbs that move about in the terrestrial environment use a variety of different gaits. The style of animal locomotion is strongly dependent on body form and on the speed of travel.
Bipedalism
Authors: Hutchinson John R , Gatesy Stephen M
Published: September 2006

Bipedalism is locomotion on two legs. Among living forms, birds and humans are exclusively bipedal.
Locomotion: Comparative Energetic Costs
Authors: Alexander R McNeill
Published: September 2006

The relative energetic cost of animal locomotion, over land, in water, and in the air, varies according to body size and the mode of locomotion adopted. Using various techniques, these costs may be measured and compared.
Human Genetics: Principles
Authors: Lam Wayne WK , Mueller Robert F
Published: September 2006

Human genetics is the study of the inheritance of biological variation as it relates to health and disease. Advances made in the last 35 years and, in particular, the developments coming out of the Human Genome Project offer the prospect of understanding and the possibility of treatment of many inherited disorders.
Dominant Traits and Diseases
Authors: Jorde Lynn B
Published: September 2006

The principles of genetic dominance and recessiveness established by Gregor Mendel in his experiments with garden peas equally apply to human genetic diseases. For dominant diseases, the inheritance of one copy of the disease allele is sufficient to produce disease. Other factors, such as incomplete penetrance, variable expression, and delayed age of onset, further influence the expression of such diseases.
Genetic Counselling
Authors: Phillips Susan E
Published: September 2006

Genetic counselling is a vital part of the field of medical genetics. Genetic counsellors are trained in the fields of genetics and psychosocial counselling, and act as advocates for families affected by genetic disorders, helping them to understand the concepts of heredity and assisting them in planning for treatment of affected individuals as well as providing options for future offspring.
Twinning
Authors: Bamforth Fiona
Published: September 2006

Twinning is the process which results in the birth of twins or higher order multiples instead of the more usual singleton. Twin studies can be used in determining genetic contribution to normal development and disease processes.
Allergy
Authors: Hanson Lars Å
Published: September 2006

Allergic diseases are defined as hypersensitivity reactions caused by the immune system reacting erroneously to external material to which it normally should not react. There are two types of allergic disease. Most common and complex, both clinically and pathogenetically, are the atopic allergies such as asthma, hay fever and anaphylaxis caused by immediate hypersensitivity reactions in which special immunoglobulin E (IgE) antibodies play a major role. A smaller group of patients have contact dermatitis caused by delayed hypersensitivity reactions.
Blood Group Genetics
Authors: Daniels Geoff
Published: September 2006

Blood groups are antigenic determinants on blood cells that represent inherited variation of the proteins, glycoproteins and glycolipids that are exposed at the cell surface. Most of the genes encoding blood group antigens, either directly or indirectly, have been cloned and the molecular bases for many of the polymorphisms are known.
Prostate Cancer
Authors: Evans Christopher P
Published: September 2006

The prostate is a walnut‐sized gland located between the bladder and external urinary sphincter through which the urethra passes. The primary function of the prostate is to produce the fluid that accompanies the ejaculate; hence, it is important in reproduction. Adenocarcinoma of the prostate is the fourth most commonly diagnosed cancer in men worldwide.
Brain Cancers
Authors: Maidment Stephen L , Pilkington GJ
Published: September 2006

The cells of the brain give rise to a variety of tumour types, foremost among them being the gliomas, a group of invasive and life‐threatening tumours whose incidence has increased since the 1960s. Despite this, the causes of brain tumours remain largely unknown and current cancer therapies serve mainly as a control rather than as a cure for this group of lesions.
Melanoma
Authors: Satyamoorthy Kapaettu , Herlyn Meenhard
Published: September 2006

Melanoma is a type of cancer which arises from the specialized cells in the skin due to a series of multiple and overlapping environmental, biochemical, molecular and genetic insults leading to metastasis and often death.
Leukaemias and Lymphomas
Authors: Wiernik Peter H
Published: September 2006

The leukaemias and lymphomas are neoplastic diseases of the blood and blood‐forming organs that are highly treatable and often curable. They cause bone marrow and immune system dysfunction, which renders the host highly susceptible to infection and bleeding. Often organ dysfunction secondary to tumour cell infiltration or tumour compression of vital structures may be apparent clinically. Tumour formation and organomegaly are more common with the lymphomas than with leukaemias.
Behaviour Genetics – Human
Authors: Comings David E
Published: September 2006

Many studies have shown that genes contribute to at least 50% of most behavioural traits and disorders, and in some cases as much as 90%. In the coming years genetic testing will be used to assist in the diagnosis and choice of treatment of most behavioural problems.
Human Genome Project
Authors: Kelavkar Uddhav P
Published: September 2006

Over a decade after it was conceived, the Human Genome Project continues to yield important biochemical information which may permanently change biology and medicine. It is invigorating to think about the transition from studying genome (DNA) structure to understanding genome function.
Bioinformatics
Authors: Adler David A , Conklin Darrell
Published: September 2006

Bioinformatics is a discipline at the intersection of computer science, information technology, mathematics and biology, and includes the study and practice of archiving, searching, displaying, manipulating and modelling biological data. Bioinformatics is applied, for example, in the construction of genetic and physical maps of genomes; nucleotide and amino acid sequence analysis; gene discovery and the prediction of protein structures.
Bioethics: ELSI
Authors: Connell Susan
Published: September 2006

Bioethics is the study of ethical issues in biology and other life sciences, and in healthcare and medicine. In human genome research, bioethics provides a framework for discussion of ethical, legal and social issues, notably genetic privacy, genetic discrimination, and gene therapy (somatic and germline).
Eugenics: Historical
Authors: Connell Susan
Published: September 2006

Eugenics is the study of the method of improving the quality of the human race, especially by selective breeding. First developed in the nineteenth century, the theory was put into practice in the eugenics policies of the UK, USA and Germany in the twentieth century. Renewed interest in eugenics has been occasioned by human genome data identification and collection.
Cardiovascular Disease and Congenital Heart Defects
Authors: Wang Qing , Chen Qiuyun
Published: September 2006

Heart disease (cardiovascular disease) is the leading cause of death in developed countries. Genetic factors play an important role in the pathogenesis of heart disease. The revolutionary advances in molecular genetics have provided new insights into the responsible genes and pathogenic mechanisms of heart disease, including congenital heart defects, arrhythmias, cardiomyopathies, heart failure, and coronary artery disease.
Phenylpropanoid Metabolism
Authors: Ibrahim Ragaï K
Published: September 2006

Phenylpropanoid compounds encompass a wide range of structural classes with diverse biological functions; their biosynthesis is associated with normal plant development and is regulated by diverse environmental stimuli. Phenylpropanoid metabolism occupies a central place in the general aromatic metabolism of plants.
Vegetable Tannins
Authors: Haslam Edwin
Published: September 2006

Vegetable tannins are phenolic plant secondary metabolites of moderate molecular size
M
r
∼ 500–3000 that have the propensity to interact with a wide range of other molecules. Interactions of vegetable tannins with proteins are of importance in nutrition, taste, astringency and bitterness, plant defence and ecology, phytotoxicity, and the conversion of animal skins to leather.
Plant Alkaloids
Authors: Woolley Jack G
Published: September 2006

Alkaloids are basic (alkali‐like), nitrogen‐containing organic constituents found in some plants. They give positive responses with Dragendorff, Mayer, Hager and Wagner reagents.
Terpenoids: Higher
Authors: Nes W David , Zhou Wenxu
Published: September 2006

Terpenoids (synonymous with isoprenoids or isopentenoids) are a diverse class of natural products that are derived biosynthetically from an intermediate with a simple five‐carbon skeleton (isopentane); higher terpenoids are complex structures that possess minimally between 20 and 40 carbon atoms. Higher terpenoids evolved coincidentally with the evolution of life and play multiple functions in nature.
Taxol
Authors: Strobel Gary A
Published: September 2006

Taxol is one of the world's most effective anticancer drugs. This drug is the product of the yew tree and some of its associated endophytic microorganisms. It is used to treat several cancers including tumours of the breast, ovary, and lung. It may serve as an example of how other anticancer drugs may be discovered.
Plant Storage Lipids
Authors: Murphy Denis J
Published: September 2006

Plant storage lipids are a major food source as well as providing a vast range of renewable industrial and pharmaceutical products. These lipids are synthesized via a complex series of pathways, the regulation of which is only just beginning to be understood. This knowledge is being used to create new transgenic oil crops and to domesticate new species to supply the ever increasing demand for plant oils.
Protozoa
Authors: Sleigh Michael A
Published: September 2006

Protozoa may be considered mostly as microscopic animals, essentially single‐celled organisms whose food is obtained by eating other organisms or their products. They play important roles in the ecology of aquatic habitats and soils, and as parasites they have very profound effects on humans both directly and through effects on domesticated animals.
Protozoan Taxonomy and Systematics
Authors: Corliss John O
Published: September 2006

Taxonomy and systematics of major groups of the Protozoa, an assemblage of so‐called lower eukaryotes, refer basically to the classification of such groups, that is, their arrangement into a hierarchy of evolutionary interrelated groups (taxa) of scientifically named phyla, classes, orders, etc.
Protozoan Diversity and Biogeography
Authors: Patterson David J
Published: September 2006

Over 100 000 protozoa have been named. Many are associated with particular types of habitats and there is a growing view that many protozoa can be found in those habitats anywhere in the world.
Sarcosporidiosis
Authors: Mehlhorn Heinz
Published: September 2006

Sarcosporidiosis is a disease that occurs worldwide in many animals and human beings as a result of oral infections with developmental stages of several
Sarcocystis
species, the life cycle of which includes two types of hosts: a prey and a predator. Humans may be involved in both groups.
Protozoan Evolution and Phylogeny
Authors: Corliss John O
Published: September 2006

The study of the evolution and phylogeny of the groups comprising the Protozoa, the so‐called lower eukaryotes, serves to elucidate the interrelationships between these, mostly unicellular, forms. They occupy an important ‘gap‐bridging’ position on the overall ‘tree of life’ between the more primitive unicellular bacteria (all prokaryotes) and the higher eukaryotes (multicellular plants, fungi, and animals).
Protozoan Sexuality
Authors: Dini Fernando , Corliss John O
Published: September 2006

Sexuality in the mostly unicellular Protozoa (lower eukaryotes), as in the higher eukaryotes (animals, fungi, plants), basically involves an activity, obligate or facultative in the life cycle, in which differentiated haploid gametes (or gametic nuclei) fuse to form a diploid zygote (or zygotic nucleus) which, in turn, develops – via a series of asexual cell divisions, the first of which sometimes includes secondary reduction to nuclear haploidy – into a new population or generation of the organism.
Protozoan Pathogens of Humans
Authors: Mehlhorn Heinz
Published: September 2006

Several protozoa are causes of important diseases that kill millions of animals and humans every year. In addition to known parasites, many so‐called opportunistic agents increase the infection risk, especially for immunocompromised people.
Protozoan Pathogens: Identification
Authors: Walochnik Julia , Aspöck Horst
Published: September 2006

The identification of protozoan pathogens is based upon direct detection of the causative agent in clinical specimens and/or upon detection of specific immune reactions of the host. Different techniques, such as staining and biochemical, molecular biological and serological methods are involved.
Alveolates
Authors: Sleigh Michael A
Published: September 2006

Three groups of Protozoa, the ciliates, dinoflagellates and sporozoans have been grouped together as ‘alveolates’ because typical cells in all three groups have a pair of subsurface membranes, forming inflated or flattened alveoli (fluid‐filled cushions), beneath the surface membrane. The close relationship between the groups has been confirmed by molecular sequence analysis.
Trypanosomiases
Authors: Gibson Wendy
Published: September 2006

Trypanosomiases are tropical diseases of vertebrates caused by parasitic trypanosomes in Africa and South America and transmitted by insect vectors. The human trypanosomiases are known as African trypanosomiasis (sleeping sickness) and Chagas disease.
Amoeba
Authors: Anderson O Roger , Rogerson Andrew
Published: September 2006

Amoebae are single‐celled eukaryotic microorganisms that move by characteristic surface projections of the cell known as pseudopodia. Taxonomically, they belong among the heterotrophic protozoa and are grouped with photosynthetic protozoa in the Protista. They are important as members of microbial communities and only a few are known to be human pathogens.