Racial differences...

[Viking]

Without having read the entire thread, and without knowing too much about this; I've got one question: From a darwinistic evolutionary perspective, what reasons would there be for certain so-called "races" to become more intelligent than others?

I think none, really. I mean, it's obvious that different environments require different physical attributes - such as dark skin in warmer climates, and pale in colder - but it's not like surviving in for example a European climate requires higher intelligence than surviving in an African climate.

Natural selection does not operate with reasons, so that is a moot point. Random mutations and probabilities are what that matters. If some individual is carrying a mutated gene that gives him greater intelligence, then that is a potential advantage. So if he breed, the offspring of his that also carry the genes will have a greater chance of survival, provided that they are otherwise fit. As generations passes, this gene has a potential to become more widespread throughout the population since its carriers are more clever than the individuals that lack the gene. By pure chance, or because of genetical differences between the populations already present, this process could have different paces or take different routes in the two populations. I think the random element makes the evolution unpredictable.