BLG 144 Lecture Notes - Lecture 3: Allele Frequency, Genotype Frequency, Assortative Mating
Document Summary
Predictions of changes in allele frequency: changes in allele frequency occur by sexual reproduction random fusion of egg/sperm, dominant alleles increase in frequency when gametes combine randomly and the gene is halved. Hardy weinberg thought of the whole population, what happens when all individuals bred. Gene pool: when all gametes produced in each generation go into a single group and then combine randomly to from offspring. Gene has two alleles a1 and a2 p+q = 1 p = a1 alleles q = a2 alleles. Frequency of a1a1 genotype (homo dom) = p2. Frequency of a1a2 genotype (hetero dom) = 2pq. P2 + 2pq + q2 = 1 > hardy weinberg equation. Hardy weinberg principle to be active 5 assumptions: no allele frequency change occurs/genetic drift, no natural selection, no gene flow, no mutation, random mating. Natural selection: produces adaptation increases frequency of those alleles that contribute to reproductive success in an environment. Genetic drift: causes random fluctuations in allele frequencies.
