ANTH 110 Chapter Notes - Chapter 3: Sewall Wright, Genetic Drift, Flor
Document Summary
Segregation: the random sorting of chromosomes in meiosis. Crossing-over: exchanges pf sections of chromosomes from one chromosome to another. Genetic recombination produces variety, which is essential for the operation of natural selection: major source of variety is mutation. Mutation: a change in the dna sequence, producing an altered gene. Although it"s diffi(cid:272)ult to esti(cid:373)ate the p(cid:396)opo(cid:396)tions of mutations that are beneficial, neutral, or harmful- some are lethal. Even though most mutations may not be adaptive, those that are will multiply in a population relatively quickly by natural selection. Founder effect: a small group of organisms recently derived from a larger population migrates to a relatively isolated location. Cline: the gradually increasing (or decreasing) frequency of a gene from one end of a region to another. Gene flor may occur between distant as well as close populations: long-range movements of people, to raid trade or settler, may result in gene flow- but not always.
