BIOL 1102 Lecture Notes - Lecture 22: Allele Frequency, Directional Selection, Genotype Frequency
Document Summary
Micro-evolutionary forces: forces that cause biological evolution: mutation, non-random mating (sexual selection, natural selection, gene flow, genetic drift. Mutations: dna mutations are the source of all genetic variation. An arena where males gather to display for females. Both sexes are choosing mates: negative assortative mating. Negative assortative mating can produce a pattern of stabilizing selection. There are alleles for white fur and dark fur in mice that live in dirt. Heterozygotes have light brown fur that help them blend in best. Eventually the white and dark fur mice are eaten by predators, so only heterozygote light brown fur is common: positive assortative mating. Dark mice blend in well in the dirt and white mice blend in well with the sand, so it is the light brown mice that end up being preyed on. If there is a dominance relationship between alleles. Population shifts in one direction, towards color being either darker or lighter.
