The Hardy-Weinberg Law seems to make good model, but I wonder how often it turns out to be accurate when looking at real life groups due to all these factors that may disrupt the frequency of alleles within a population?

It is interesting to think that physical barriers can cause different phenotypes to form, which leads to speciation. I wonder if the opposite could happen when different species are brought close enough together and evolve to have similar traits that a advantageous to a common environment. After all, these species are meant to share common ancestor.