Final answer:
The oversimplification in population genetics principles is due to the reliance on the Hardy-Weinberg principle that assumes idealized conditions not met in nature. The complex reality includes phenomena like selection, mutation, and genetic drift that alter allele frequencies and genotypic distributions.
Step-by-step explanation:
The principles of population genetics presented in chapters 6 and 7 are somewhat of an oversimplification because they often rely on the Hardy-Weinberg principle, which assumes a non-evolving population in equilibrium. In reality, actual populations are affected by various evolutionary forces such as genetic drift, mutation, migration, and selection. This results in changing allele frequencies and genotypic distributions, thereby deviating from the idealized conditions presented by the principle.
The simplest models in population genetics do not account for complexities such as multiple alleles, linked genes, or various modes of selection. Additionally, the Hardy-Weinberg equilibrium assumes random mating, no mutation, no migration, infinite population size, and no selection, which are conditions rarely met in nature. Thus, the principles examined in these chapters provide only a foundation, and scientists recognize that natural populations often evolve and diverge from the theoretical baseline provided by Hardy-Weinberg.
Further complicating the understanding of population genetics is the fact that inheritance was not understood during the time of Darwin. Only with Mendel's principles of inheritance and the subsequent development of the modern synthesis, which combined genetic principles with the theory of evolution, was a more coherent understanding achieved. These developments highlight how the principles in earlier chapters serve as a starting point for understanding the complex dynamics of real-world population evolution.