ANTH 1210 Lecture Notes - Lecture 17: Zygosity, Genetic Drift, Darwinism

• School: University of Manitoba
• Department: Anthropology
• Course: ANTH 1210
• Professor: Haskel J.Greenfield

Document Summary

Types of selection: directional, normalizing - trait that will work best for environment (ex: birth weight) Darwinian: natural selection is a directional process (pressures of environment, push genotype and phenotype in specific directions, adaptation) Random processes that affect gene frequencies occurs in small isolated populations. Produces changes in gene combinations from one generation to the next. In large population, random change will not affect overall structure of population (new changes, swamped) In small populations, more likely to have effect/impact. Creates homozygosity within a few generation, homozygous population can be reached (all blue eyes, blond hair) When few settlers, colonists or survivors of a catastrophe establish a new population. Loss in genotypic variability (leads to population homozygosity) Gene frequency of the founders will differ significant from parent population (sampling error) Found represent a small and biased sample of original parent population. Counteracts the tendency of genetic drift and naturals selection cause populations to be pushed apart genetically.