How Not Meeting The Assumptions Of The Hardy-Weinberg Principle Aid In Evolution - Term Paper Example

298). The Hardy-Weinberg model is applicable to the context of populations of diploid, sexually reproducing individuals (Andrews 65). For a population to be in Hardy-Weinberg equilibrium, certain assumptions must be met. Andrews, Hartl and Clark and Hillis et al. comprehensively described and summarized the following assumptions, 1. Natural selection is not acting on the locus in question, indicating that there is no differential selection among genotypes. Individuals with different genotypes have equal probabilities of survival and equal rates of reproduction. 4. Population size is infinitely large, which means that genetic drift is not causing random changes in allele frequencies due to sampling error from one generation to the next.

As all natural populations are finite and they are subject to drift. However the effects of drift are more pronounced in small than in large populations. where, p2, 2pq and q2 are the expected frequencies of genotypes AA, Aa and aa in zygotes of any generation, p and q are the allele frequencies of A and a in gametes of the previous generation of the population (Hartl and Clark 75). As there are only two alleles at a locus, p + q=1. “The Hardy-Weinberg genotype frequencies, p2 + 2pq + q2, represent the binomial expansion of (p + q) 2, and also sum to one”.

(Andrews 65) “In case of loci with more than two alleles, it is possible to apply the Hardy-Weinberg theorem, in which case the expected genotype frequencies are given by the multinomial expansion for all k alleles segregating in the population: (p1 + p2 + p3 + . . . + pk)2”. (Andrews 65) Fig. 2- “Generation I of this population consists of migrants from several other populations, thus violating the Hardy-Weinberg assumption of no migration. Notably, the generation I has more homozygous individuals and fewer heterozygous individuals than would be expected under