However, I'd like to play devil's advocate with a thought experiment. Specifically, I'd like to address your fundamental assumption of equally distributed evolutionary pressure. It's true of our ancient history (which covers most of human existence), but it feels premature to ignore the potential impact of modern human societies over the last few millenia.
Imagine two identical human groups, one which spends 1000 or so years in an urban or quasi-urban setting, and one which spends the same time as hunter gatherers. Seems like some traits would be self-selected more heavily in one group vs the other based purely on environmental pressure. I.e. someone gifted with an above-average capacity for abstract modeling, but with - say - severe myopia, would find it easier to procreate in an environment where their skills are valued and their physical limitations negated, and vice versa.
Human history is long, but reproductive pressure can have a discernible impact on a population even over the relatively short time scale covered by human civilization. It's an imperfect analogy, but for instance new dog breeds only require a handful of generations (<10) to be both physically and behaviorally discernible. Why should reproductive pressures applied by different social environments, stretched over millenia, not have an impact on human populations?