Pleiotropy: Got a new question on the reddit AMA

post replyIamAn evolutionary biologist. AMA!

from NorrisChuck via /r/IAmA/ sent 4 days ago

Who is more evolved? White man or a Black man?

bjornostman[S] 1 point 108 milliseconds ago

Wut?! As a scientists I am in principle for asking any question one can think of, but this honestly smells of racism, which I find reprehensible. If you did not mean it like that, then fine, but know that you sound like one, ok?

Which white man and which black man? Barack Obama and Tiger Woods? Derek Jeter and Malcolm Gladwell? A sámi and a khoisan?

Neither is more evolved than the other. In fact, unless you define what you mean by "more evolved", the question can be interpreted in multiple ways that can have different answers.

Any two men, regardless of color of skin or ethnicity, share a common male ancestor not very long ago (in evolutionary terms and compared to, say, the ancestor of humans and chimpanzees). Since then all sorts of mutations have happened in both lineages, and they may have slightly different number of of DNA mutations (aka substitutions).

Best hypothesis is that the white man has evolved white skin to be better able to synthesize vitamin D when the rays of the sun hits his skin, whereas the black man has evolved black skin as protection against the rays of the sun. I don't know what the phenotype or genotype of the common ancestor was, and without that information, it is hard to answer the question.

Since the two lineages split some 200,000 years ago, they have both continued to evolve in slightly different directions, also in other traits than skin color, like the sickle-cell trait, whereby some resistance against malaria is afforded. The last common ancestor was no doubt homozygous (so the man who is heterozygous is then more evolved in this trait, one could say if forced to talk about it that way, which no scientists ever do).

Lastly, there is nothing inherently better or worse about being "more evolved". More evolved doesn't equate to better, more intelligent, or faster, or more civilized, or more bigoted. Some people are dumb as heck no matter what the color of their skin is. Some people.

bjornostman[S] 1 point 39 milliseconds ago

1 comment:

The PhytophactorJanuary 29, 2014 10:28 AM
"More evolved?" Biologically this phrase means nothing, But of course the question leads you to think "more evolved" means more advanced versus more primitive. Now in common language we do tend to speak of primitive organisms, but actually all living organisms are equally evolved, but some retain more characters from a common ancestor whereas others are more derived. But that's about it. Nonetheless you offered a very reasonable answer.

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