You shouldn’t need a study. It should be common sense. We are different, fact. Dogs are different, cats are different. Our skin colours means we react to sunlight differently, is it not beyond the bounds of possibility that there are other small things that make a difference?
Look at your average Negro and your average Mongoloid. There may have been cultural differences in the past that have influenced how they appear now but the fact is that now they are different. One is usually taller than the other for example. I suggest then that the longer limbs might predispose to faster running?
Our culture may influence what we do in the immediate but over time, (significant time maybe), it makes a particular sub species physically different. FACT.
There's a huge gap between physical and physiological, the latter of which, when used in this context, assumes vast differences between the races, to the point the different races would actually be
different race.
That isn't the case. The differences are mostly environmental adaptations, and are almost miniscule changes when considered against the vast whole. Like the distinction between a black person and a white person are almost razor thin. A black person has darker skin and generally less body fat because that's a more advantageous build for a hot environment where the sun's beating down on you 24/7. While people tend to be a little more barrell chested, and have more body fat because that's a good fit for mountainous, cold environments like what you get in Europe. Beyond that though, there aren't any differences between a black person and a white person. We can donate blood between each other, share organs, have kids, all that good stuff. Mentally we're the same, having the same brain sizes, same neuronal count, same neural pathways performing similar tasks, etc. etc. Beyond the superficial, there are no differences between black, white, asian, whatever.
Height, facial features, skin tone...it's not like comparing dogs and cats. It's like comparing a calico cat and a piebald cat from the same litter.
edit: See, you're saying stuff like "species" and "subspecies" when referring to the different races, which is entirely the wrong nomenclature. Considering that humanity has among the least amount of genetic diversity of any animal species on earth, and you don't have to go back that far to find a common ancestor, the better way to describe the races is to refer to them as a different family lineage. We're all cousins, a few hundred times removed.
The Out of Africa diaspora wasn't all that long ago evolutionarily speaking. There hasn't been nearly enough time for all these different branches to evolve into anything even remotely different.
