ch 22

Question 1

natural selection

Answer 1

the result of variation, differential reproduction, and heredity.
Natural selection just selects among whatever variation already exists in the population.
acts on variation in a non-ranom way and selects genetic variants that aid survival and reproduction

Question 2

homology

Answer 2

similarity resulting from common ancestry

Question 3

what does evolutionary theory predict

Answer 3

that related organisms will share similarities that are derived from common ancestors

Question 4

homologous structures

Answer 4

anatomical resemblances that represent variations on a structural theme present in a common ancestor

Question 5

analogous structures

Answer 5

have similar function but not similar origin.

they have separate evolutionary origins but are superficially similar because they evolve to serve the same function.

Question 6

biogeography

Answer 6

animals and plants in different locations but similar niches tend to look or act the same

Question 7

darwins two major points in his book

Answer 7

many current species are decscendants ofancestral species

natural selection is a mechanism for this evolutionary process