| Disclaimer: I have no particular expertise on this topic. > A tremendous amount has changed in that time. Height, immune system changes, lactose tolerance, blue eyes, different hair colors, digestive system changes. None of those are tremendous changes. We're talking about a single mutation that disables a certain gene in most cases above, right? Also they aren't universally spread among humans, and it seems like many people from divergent genetic lines can adapt to a modern culture just fine. I know Jared Diamond makes a strong claim that the human brain really isn't that different across humans, citing, e.g. friends from New Guinea tribes who could happily and easily learn to use computers when they were exposed to them. > There's strong evidence for significant changes in IQ, time preference, and other psychological traits. Any citation for that first claim in particular? I know that (though the strong social norm is to avoid these topics at all cost), e.g. the population of Ashkenazi Jews has a higher average IQ than the mean. But individual variation is still far more important. And it's not clear how "significant" the difference is, if we're talking about the magnitude of changes that make culture and language possible vs impossible. E.g. if maybe 1% of the population could be math PhDs vs 0.2%, is that so significant? > One basic insight of the selfish gene is that a gene can be regarded as being in several places at once if it has copies in those places. It acts as the same gene, not separate copies. But this is true across populations too. So, it may not have been in the best interest of your genes to directly reproduce, vs spending the effort to help your family or tribe. |