How do genotypes form when every individual is equally likely to survive and reproduce?
To investigate the relationship between parental and offspring generation genotype frequencies when a population is not being influenced by an agent of evolution, let’s review how offspring genotypes are formed when every potential parent is equally likely to survive and reproduce. Under these conditions, the allele contributed by one parent does not and is not influenced in anyway by the allele contributed by the second parent; there is no sexual selection. Nor is a parent’s likelihood of contributing alleles to the next generation influenced by environmental circumstances that favor survival of one parental phenotype over another or by chance events as occur during genetic drift. Thus, if survival and reproduction are truly random events, each parent’s allelic contribution to fertilization is a statistically independent event. Put differently, the genotype of the resulting offspring is the result of two independent, chance events – one chance event per allele. Imagine drawing two par
