1Bio1222Lecture outline: genetic variation Lecture outline: genetic variation •What is it and why does it matter?•Selection: does it always reduce genetic variation? •Other evolutionary mechanisms:– Mutation– Migration–Genetic drift–Nonrandom matingBio1222Genetic variation•Individual level–Proportion of heterozygous loci•Population level–Proportion of polymorphic loci–Alleles per locus–Average heterozygosity
has intentionally blurred sections.
Sign up to view the full version.
2Bio1222Why does it matter?Why does it matter?••Bio1222Why is there (usually) so much?Why is there (usually) so much?•Classical model of variation–Any allele is either helpful or harmful–selection should eventually replace bad with good alleles–So, genetic variation should be rare and temporary•But, most natural populations contain lots of GV… ???