ANT 101 Lecture Notes - Lecture 21: Evolutionary Anthropology, Allele, Genetic Drift
Document Summary
Random changes in a gene pool over time resulting from chance alone. Mating is not entirely random, since there are always individuals that do not or cannot produce offspring. Due to finite population size and non-random mating patterns, chance determines which alleles within a population are maintained and which are lost. Ultimately reduces genetic variation within a population. Populations experiencing a drift have a reduced ability to respond to new selective pressures in the ever-changing environment. Evolutionary genetic drift is more likely to occur and proceeds faster in smaller populations, such as rare species. Genetic drift can lead to increased variation between populations. 2 forms (directly associated with small populations) Occur when a new subpopulation is composed of only a few individuals from the original population. First consequence is that individuals may have reduced genetic variation from the original population. Second consequence is that these individuals may have a non-random sample of genes in the original population.
