Topic 1 Evolution: Macroevolution

Question 1

• This theory says that evolution occurs by the gradual accumulation of small changes. However, this is unlikely to be valid because intermediate stages of evolution are missing in the fossil record; fossils only reveal major changes in groups of organisms

Answer 1

Phyletic Gradualism

Question 2

• This theory says that evolutionary history consists of geologically long periods of stasis (stability) with little or no evolution followed by geologically short periods of rapid evolution. Absence of fossils revealing intermediate stages of evolution is considered data that confirms rapid evolutionary events

Answer 2

Punctuated Equilibrium