Explain why genetic drift may be important when captive populations of animals or plants are started with just a few individuals.

Which of the following statements is true of microevolution? (Select all that apply.)

a. It is a change in allele frequency within populations.

b. It is caused by inheritance of characters acquired during the life of an organism.

c. It is only seen when some allelic variants cause individuals to have increased reproductive success.

d. It always leads to adaptation.

e. It is caused only by natural selection.

Agents of allele frequency change in populations include (select all that apply):

a. genetic drift.

b. meiosis.

c. mutation.

d. segregation.

e. natural selection.

Agents that consistently produce adaptive evolution (adaptation) include (select all that apply):

a. genetic drift.

b. mutation.

c. meiosis.

d. natural selection.

e. gene flow.

Mutations are (select all that apply):

a. generally beneficial.

b. sometimes heritable

c. always caused by changes in single base pairs of DNA.

d. the ultimate source of new genetic information.

e. prone to occur with great frequency.

Finches in the Galapagos experienced __________selection on beak depth following a drought; the African finch P. ostrinus experienced __________ selection on beak size because it eats either very small, soft seeds or much larger, hard seeds.

a. stabilizing, directional

b. sexual, disruptive

c. directional, disruptive

d. disruptive, directional

e. stabilizing, disruptive

The age of the Earth has been established through the use of ________, in which scientists test for the ________ of parent and daughter elements in a given sample of rock or other material.

________ features are features in different species that are the same in structure owing to inheritance from a ________.

The auricular muscles of human beings and the wings of ostriches are examples of _______ characters.