BIO 1306 Lecture Notes - Lecture 24: Allele Frequency, Gene Duplication, Genetic Drift
Document Summary
The smallest unit of evolution: a common misconception is that organisms evolve during their lifetimes, natural selection acts on individuals, but only populations evolve. Microevolution = a change in allele frequencies in a population over generations: three mechanisms cause allele frequency change, natural selection (only this causes adaptive evolution, genetic drift, gene flow. Sources of genetic variation: new genes and alleles can arise by mutation or gene duplication, sexual reproduction can result in genetic variation by recombining existing alleles, things to remember about mutation: In animals, most are not passed on to offspring. Sexual reproduction: sexual reproduction can shuffle existing alleles into new combinations, in organisms that reproduce sexually, recombination of alleles is more important than mutation in producing the genetic differences that make adaptation possible. Concept 23. 1: hardy-weinberg eq. can be used to test whether a pop. is evolving.
