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Population Genetic. Hardy-Wienberg Law Genetic drift Inbreeding Genetic Bottleneck Outbreeding Founder event Effective population size Gene flow. Population Genetics. Genotype, phenotype locus, genotype frequency, allele frequency. Determining the genotype for an enzyme in a fish.
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Population Genetic • Hardy-Wienberg Law • Genetic drift • Inbreeding • Genetic Bottleneck • Outbreeding • Founder event • Effective population size • Gene flow
Population Genetics • Genotype, phenotype • locus, genotype frequency, allele frequency
IDHP (isocitrate dehydrogenase) from a grasshopper Individuals 2 1 3 . . . AA Aa aa
Genotype and Phenotype • Genotypes AA, aa (Homozygous), Aa (Heterozygous) • Phenotype trait X = AA and Aa , trait Y = aa • Alleles A and a • If p = proportion of allele A and if q = proportion of allele a • Then p+q = 1 • Knowing p and q the Hardy-Wienberg Equilibrium gives the expected frequency of the three genotypes as: • (p+q)2 = p2 +2pq + q2 = 1 AA = p2, aa = q2 and Aa = 2pq
Hardy-Wienberg EquilibriumAssumptions • Population size is very large • Random mating is occurring • No mutation is taking place • No immigration (geneflow) • No selection is occurring
Inbreeding A alleles common by descent
Effective population size • Founder effect • Genetic bottleneck • Outbreeding depression • Gene flow