Evolution

Question 1

What are the two core principles of evolution?

Answer 1

Descent with modification

Natural selection

Question 2

What is descent with modification?

Answer 2

Particular groups or species undergo modification in successive generations, sometimes resulting in the formation of new, separate species

Question 3

What is natural selection?

Answer 3

Process in which differential adaptation of organisms to their environment selects those traits that will be passed on with greater frequency
The primary and most significant of several processes that result in life evolving

Question 4

What is adaptation?

Answer 4

As a result of natural selection, organisms change (evolve) over time

Question 5

Understand and provide examples of convergent evolution

Answer 5

the independent acquisition of the same biological feature in unrelated lineages
features arising through convergent evolution are termed analogies, whereas homologies have a common evolutionary origin
Shark (fish)
Ichthyosaur (reptile)
Dolphin (mammal)

Question 6

What is different between convergent evolution and homologous structures?

Answer 6

Traits arising through convergent evolution are termed analogous structures, whereas homologous structures have a common evolutionary origin

Question 7

List categories and examples of “homology” evidence that species are related, including structural, developmental and molecular.

Answer 7

homologies:  morphological or biochemical traits that are similar
structural
Functions vary but underlying structure 
   similar
developmental
morphology of embryos (pharyngeal slits)
h = hind limb bud in 
	dolphin embryo

Question 8

What are vestigial features in humans?

Answer 8

The existence of vestigial traits supports the idea that traits that are selected against may be minimized, and give evidence of the ancestral condition. Vestigial traits imply a different ancestral form and thus support the idea that species change over time.
I.E. Tails

Question 9

Describe Darwin’s insights into descent with modification and natural selection.

Answer 9

Darwin saw a pattern: these animals were related to an ancestral species found on the mainland of South America.
Many of the species he saw had common mainland ancestors, but those on the islands had diverged into separate species

Question 10

Discuss the evidence that species change over time, including…
Extinctions

Answer 10

extinction means living world is not “fixed”

fossil record, species not static

Question 11

Discuss the evidence that species change over time, including…
Transitional

Answer 11

“law of succession”

striking resemblance in geographic proximity, and in geological layers

Question 12

Discuss the evidence that species change over time, including…
Vestigial traits

Answer 12

coccyx, appendix?
gene families (gene duplication followed by shift in function)

Question 13

Discuss the evidence that species change over time, including…
contemporary response to environment

Answer 13

drug resistance, pesticide resistance, herbicide resistance

Question 14

Define natural selection

Answer 14

natural selection: Individuals with certain heritable traits will survive and reproduce more, leading to a change in the traits of a population.

Question 15

Explain why Darwin’s theory of natural selection is a process component to the theory of evolution.

Answer 15

Darwin’s major contribution: recognizing a process for descent with modification, natural selection.
Darwin recognized and expressed natural selection, the process that could explain the pattern of “descent with modification.”

Question 16

Understand how scientific arguments against evolution in the late 1800’s were reconciled

Answer 16

Age of the earth (it had to be old in order for evolution to proceed from single cells to complex organisms)
Genetic mechanism (for transmitting adaptations to subsequent generations)