Raven Johnson Biology Chapter 20 Answers to Review Questions 1. Macroevolution refers to changes in populations of plants and animals so that new species develop from old ones.
Microevolution refers to changes in allele frequencies within a species.
Adaptation results from the possession of features that promote the chance of an organism's survival and reproduction. The natural selection of Darwin's concept of evolution is the process, and adaptation is the result. Genetic polymorphism refers to genes that have more variation than can be explained by mutation. Invertebrates are more polymorphic than vertebrates. The variation provided by genetic polymorphism is a significant source of raw material upon which natural selection can act.