ANTHR101 Lecture Notes - Lecture 5: Phenotypic Plasticity, Allele Frequency, Population Genetics

• School: University of Alberta
• Department: Anthropology
• Course: ANTHR101
• Professor: Francois Larose

Document Summary

Natural selection part 2: random mating: does not decrease or increase variation, but maintains it, natural selection: acts on the variation by differential reproductive success. Not a genetic change and is temporary e. g. tans. *phenotypic plasticity: types of selection, directional selection: the particular phenotype of a species is changing consistently in one particular direction. Horses consistently favouring larger body size over time: stabilizing selection: extremes are selected against, decreasing genetic diversity. Favours the middle ground phenotype, maintain this singular phenotype over an extended period of time: disruptive selection: the extreme phenotypes are favoured. Makes (different) populations more similar to each other because they share alleles in common. Within populations that have received the gene flow they are more different from other individuals within the same population: *genetic drift: a change of allele frequencies as a consequence of random changes in population size.