ANT202H5 Lecture Notes - Lecture 5: Allele Frequency, Heterozygote Advantage, Genetic Variation
Document Summary
Filters - does not create genetic variation: changes relative frequency of allele over time, genotypic differences in ability to survive & reproduce. Fitness - organism"s probability of survival & reproduction still. Depends on type of selection & initial allele frequencies: reduces frequency of harmful recessive mutant allele. Depending on environment: 2 populations similar environment. Ns will take place in same way in both groups. Reduces genetic differences between population: 2 populations different environments. Natural selection causes evolution: relative fitness = measure of relative genetic contribution of genotype to next generation (w) Genotypes = units of selection: highest fitness = 1 to 0 = genotypes do not survive or reproduce. Selection coefficient(s: measures relative strength of selection acting against genotype, compared with max. fitness genotype (w = 1) s = 1 - w s = 1. No contribution to next generation s = 0. Effect of selection on allele frequencies: depends on, differences in fitness genotypes.
