The thing is that the "power trait" isn't just any trait -- it is the mother of all adaptive traits. A powerful person has extremely higher chances to survive and procreate, and with a powerful mate to boot. From what we know about evolution and genetic traits -- see the Price equation[1] and evolutionary game theory[2] -- adaptive traits can't be distributed in such a non-uniform way, especially if they are so extremely adaptive. And, of course, no trait heredity can explain power revolutions that occur over centuries. Even if we don't know everything, I can't believe that we'd be so wrong. Relativity is just a better approximation of reality than Newtonian dynamics.

Of course, you could explain things as follows: the population of each race is already adapted to its local environment (with strongly adaptive traits spread noisily but uniformly in each population), but those traits -- like skin color (which is now non-adaptive) -- haven't yet had time to adapt globally since the races started to mix. This poses a difficult problem, that can be stated in two ways: 1/ if there are plenty of, say, powerful black people in the US (although on average the black population is much less powerful), how come those people's power traits didn't spread among blacks in Africa (remember, it's an extremely adaptive trait) 2/ How come the super-adaptive power traits is so unequally distributed within each trait. The first question can be answered by saying that power takes different forms in different cultures, and the American power trait is not adaptive in Africa. This is an interesting hypothesis, but it doesn't really fit with what we know about power. Sure, there are cultural differences, but they are rather superficial and don't coincide with relative inter-race power (e.g. Japanese culture displays the same emphasis on authoritative power and tradition as African or Arab culture). The second question simply can't be answered with our mathematical evolutionary models. And, of course, there's still the power-revolution problem which seems to preclude any kind of genetic heredity.

All of those problems can be explained through changes to the environment, but the pertinent environment is social rather than natural, so you'd have to see genetics as a mediating factor of social forces. Even that is unlikely because the time frames are wrong for evolutionary changes.

What is interesting, though, is that if we take the environment to be a social environment and shrink the time frames, we could see something similar to evolutionary models (only much more volatile). This is why Richard Dawkins introduced the concept of the meme[3], or "social gene", to hypothesize that social ideas can display similar behavioral models to biological genes.

And I understand the scientific method just fine, thank you. Knowledge isn't binary (Gettier problem aside); there are levels of knowledge. We know genetics and evolution enough to conclude that a social explanation is more probable than a genetic one for similar reasons we can conclude that problems in experimentation and data analysis are a far likelier explanation to the Bem experiment than weak ESP. In physics, too, most scientists decide not to spend their time researching hypotheses that appear unlikely or pose harder problems than others, even if they can't be completely rejected outright, opting instead to focus on the more promising ones.

[1]: https://en.wikipedia.org/wiki/Price_equation

[2]: https://en.wikipedia.org/wiki/Evolutionary_game_theory

[3]: https://en.wikipedia.org/wiki/Meme