Few features of humanity are as obvious as the wide array of inherited diversity visible in our outward features. It's also evident that people whose ancestry traces to a particular geographic region typically appear similar to one another and different from other geographic regions. Moreover, we as humans have an almost innate propensity to compartmentalize nearly everything into discrete categories, even when lines that distinguish those categories are complex, blurred, or nonexistent. As an inevitable consequence, people have been subjected to categorization into what we call human races throughout much of the past several centuries.