Question: When did a model of heredity begin to be integrated with that of variation?
Answer: in the 1930s and 1940s

Question: What was the modern evolutionary synthesis named?
Answer: Neo Darwinian Evolution

Question: What is one possible objection to the theory of integrated variation?
Answer: often no intermediate forms between closely related species are found

Question: Why did Darwin wonder why all of nature isn't chaotic and random?
Answer: why, if species have descended from other species by insensibly fine gradations, do we not everywhere see innumerable transitional forms?

Question: What did Darwin ultimately decide was the reason that nature is not a chaos of variation?
Answer: the competition between different forms, combined with the small number of individuals of intermediate forms, often leading to extinction of such forms.

Question: What are some flying animals that Darwin thought might have evolved from bats?
Answer: flying squirrels, and flying lemurs

Question: What example did Darwin give of eyes evolving?
Answer: simple eyes found in invertebrates, starting with nothing more than an optic nerve coated with pigment

Question: How did Darwin justify his theory not breaking down?
Answer: any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.

Question: How does Darwin theorize that instincts have evolved in slave-making ants?
Answer: He thought it reasonable that species with an extreme dependency on slave workers had evolved in incremental steps.

Question: How does Darwin theorize that instincts have evolved in bees?
Answer: He suggested that bees that make hexagonal cells evolved in steps from bees that made round cells, under pressure from natural selection to economise wax

Question: What did Darwin notice specifically about slave-making ants?
Answer: some species of slave-making ants were more dependent on slaves than others

Question: Why would hybrids have characteristics that keep them from being fertile?
Answer: in order to preserve separately created species

Question: What are Darwin's thoughts on producing hybrids of related species?
Answer: the viability and fertility of the hybrids, varied greatly, especially among plants

Question: What conclusion did Darwin come to after realizing that some diverse species were able to create variations easily, while other species thought to be closely related had difficulty?
Answer: support the view, that there is no fundamental distinction between species and varieties

Question: Why did Darwin introduce a new chapter in On the Origin of Species in the sixth edition?
Answer: to respond to criticisms of earlier editions

Question: What was one of the objections that Darwin addressed in his new chapter in On the Origin of Species?
Answer: that many features of organisms were not adaptive and could not have been produced by natural selection

Question: Which of Darwin's books featured a plant whose elaborate structure aided with fertilization by insects?
Answer: Fertilisation of Orchids

Question: Which scientist was addressed the most often in the new chapter of On the Origin of Species?
Answer: George Jackson Mivart

Question: What was Darwin's response to the claims that certain animals could not have evolved through natural selection?
Answer: Darwin proposed scenarios for the incremental evolution of each feature.

Question: Whose argument did Darwin borrow that geological record is very imperfect, because fossilization is rare?
Answer: Charles Lyell

Question: Which book written by Charles Lyell contains the argument that fossils are too rare to be used as proof of life suddenly arising?
Answer: Principles of Geology

Question: What did Darwin hope to find as he continued to explore new geologic discoveries?
Answer: that new finds would occasionally reveal transitional forms

Question: How long did Darwin estimate the erosion of the Weald to be?
Answer: 300 million years

Question: What is the name of the group of well-developed organisms that were discovered within fossil-bearing layers?
Answer: the Cambrian explosion

Question: How did Darwin expect species to change and evolve?
Answer: slowly, but not at the same rate

Question: What did Darwin believe were the key things needed for variation of species to form?
Answer: variability and change in the environment

Question: Which scientist theorized that the earliest members of a class in a species were simple and generalized?
Answer: Richard Owen

Question: What did Darwin discover about more recently extinct species?
Answer: Recently extinct species were more similar to living species than those from earlier eras

Question: Why couldn't differences in flora and fauna be explained by differences in regions alone?
Answer: South America, Africa, and Australia all have regions with similar climates at similar latitudes, but those regions have very different plants and animals

Question: What did Darwin consider that could explain why different regions could have such different species when they are close together?
Answer: barriers to migration played an important role in the differences between the species of different regions.

Question: What was the combination of effects that Darwin considered the most important in determining the differences in species that evolved separately in similar environments?
Answer: His explanation was a combination of migration and descent with modification.

Question: What theory does Darwin discuss that is related to the importance of homologous structures?
Answer: morphology

Question: What are some examples that Darwin gives of species whose basic form of limbs is similar, but who have vastly different uses for them?
Answer: the hand of a man, formed for grasping, that of a mole for digging, the leg of the horse, the paddle of the porpoise, and the wing of the bat

Question: What does Darwin note about the embryos of many different species in the same class?
Answer: animals of the same class often have extremely similar embryos

Question: What are some examples of rudimentary organs that Darwin discusses in the chapter?
Answer: e wings of flightless birds and the rudiments of pelvis and leg bones found in some snakes

Question: What hopes does Darwin have for his theory in the natural history fields?
Answer: that his theory might produce revolutionary changes

Question: Why did Darwin avoid the topic of the origins of humans in most of his book?
Answer: so as not to prejudice readers against his theory

Question: What does Darwin allude to hoping in the final chapter of On the Origin of Species about humans?
Answer: that psychology would be put on a new foundation and that "Light will be thrown on the origin of man"

Question: What were Darwin's two important aims about evolution?
Answer: to show that species had not been separately created, and to show that natural selection had been the chief agent of change

Question: What did heknow his readers were already familiar with from Vestiges?
Answer: the concept of transmutation of species

Question: How did Darwin view Vestiges in the introduction to On the Origin of Species?
Answer: his introduction ridicules that work as failing to provide a viable mechanism.

Question: What is Darwin's belief about the accumulation of adaptive variations?
Answer: the accumulation of adaptive variations provides a scientifically testable mechanism for evolutionary speciation.

Question: What does Darwin do to show that his theory can support many theories that could not be explained by individual creation of species?
Answer: Darwin presents supporting facts drawn from many disciplines

Question: Whose scientific philosophy argued that a mechanism could be called a vera causa if three things could be shown as true?
Answer: John Herschel