I saw something interesting on Discovery channel or National Geographic a few months ago about super volcanos.
On scientist had noted that the extreme lack of human biodiveristy. Apparently human genome records indicate that the human population was almost wiped out (reduced to a few thousand) about 10,000 years ago.
This happens to coincide with a massive volanic eruption in Java. The theory is that this eruption was the cause of the depletion of the human population.
My questions are:
is there a lack of biodiversity amongst humans?
is there any academic credibility to this theory?
Certain Northern Europeans have red hair. Red hair does not occur naturally in any other part of the world. Could it be that this is a remnant of a more biodiverse human race? (I note also that Scandanavia is half a world away from Java).
You got it a bit wrong. The idea is that humans were reduced to a population of about 10k individuals sometime about 75k years ago.
What you are talking about is genetic diversity, not biodiversity (which usually means the diversity of species). And that’s a relative thing. We are relatively lacking in genetic diversity. Scientist can find more genetic diversity among a small group of chimps living close together than in all of humanity. But cheetahs are even less genetically diverse than we are.
It’s impossiible to prove, but it’s a pretty credible theory. It derives from the lack of genetic diversity.
Red hair can be found in Australian Aboriginies. Europeans are not evidence of more diversity. Modern Humans enterred Europe about 35k yrs ago.
Except India, Africa, Australia, SE. Asia and Polynesia. Red hair is very widespread. I’ve never heard of a red haired East Asian or Amerind, but they seem to be the only exceptipn.
OK. I misunderstood. But why pick out red hair? You’re just focusing on what we as humans notice about each other. It’s probably just as likely that the extremes of genetic diversity shows itself in features (like immune response variation) that are not at all obvious.
At any rate, the genes that control hair color are well within what scientist are talking about when they say that human genetic diversity is very low.
Actually, the greatest genetic diversity among humans can be found in natives of Africa. And this makes sense if you assume that all non-Africans left Africa about 60k years ago. the non-Africans have had 60k years to differentiate, but the Africans have been differentiating since the our species first came out of the genetic bottleneck, and possibly even longer.
Primarily because I have just spent a few years living in Japan and China. Red hair stands out there.
I suppose I could have used another example - gooey vs chunky ear wax consistency, or the genetic characteristic that makes some Chinese and Japanese people turn very red when they drink, or something - but with visual obviousness, red hair popped into my head.