BIOLOGY 1114 Lecture Notes - Lecture 21: Zygosity, Porphyria, Genetic Drift
8 Oct 2018
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Founder effect (continued): composition of founder population not purposefully selected to include particular genotypes, generally not random distribution of entire population, genes in low frequency, ex: porphyria veriegata: Founder effect itself is not likely to cause a population without heterozygosity: the more individuals in founding population, more likely to have genetic variation i. e. heterozygosity. Importance of randomness in shaping population genetics: genetic drift causes changes in allele frequency because non-representative sample of the population produces more gametes. Small populations may be especially vulnerable to random events, because they have less variation: even if drift is important, most mutations may have negative consequences, drift & mutation can work in concert or against each other. Migration: migration violates hardy-weinberg, can maintain genetic diversity in spite of natural selection or drift. Some aspects are random: mutation, genetic drift, migration/gene flow, these are crucial to evolution!
