Modern humans 'evolved on S Africa/Namibian border'

[struggle4progress]

Posted May 1, 2009 09:25:00

New research suggests that the modern human species first evolved in southern Africa, probably near what is now South Africa's border with Namibia.

Writing in the journal Science, the researchers say modern humans then migrated north to the Red Sea region.

The researchers spent 10 years collecting over 4 million gene samples from more than 120 population groups in Africa.

Among their findings was that Africa has more genetic variation than any other continent, and what is known as the Cape Coloured population in South Africa has the highest levels of mixed ancestry in the world ... http://www.abc.net.au/news/stories/2009/05/01/2557877.htm?section=justin

[izquierdista]

1. The Gods Must Be Crazy

Most likely the migration was to get rid of that !@#$%^%& Coke bottle.

[theoldman]

2. I guess our ancestors were brown, not black.

I read something about this many years ago. A linguist had a theory that black Africans evolved from brown Africans. As years went by they slowly outnumbered the brown ones because they were stronger.

[elleng]

8. 'splain, please.

Brown/Black? Today, VERY few true BLACK, right? Good number of dark brown, then >>>>> shades of brown etc.

[Igel]

17. Linguists don't count.

They're linguists, not geneticists.

It's likely that selective pressure pushed humans to be fairly dark for a few different reasons, and, per orthodoxy, all gave an advantage in survival to age of reproduction or enabled greater fertility. Outside of where there was a lot of sun, once there were shelters and clothing, the pressure would be reduced, and, in fact, lighter skin would be selected. Apparently paler skin was innovated at least twice.

[xchrom]

3. recommend -- i hope i get africa someday --

i wanna the Serengeti -- in my pea brain -- i imagine that's what it all looked like when we first started out.

i know it's not really like that -- just a pilgrimage.

[tabatha]

5. Namibia is wonderful

if you can get there, as is Botswana.

[aquart]

7. And if you can't travel, watch the Ladies No. 1 Detective Agency.

[xchrom]

13. ah botswana -- gorgeous.

that would be on my list.

[TechBear_Seattle]

11. To be honest, I am terrified at the thought of going to Africa

Between the religious bigots executing gay people in the east and south, the civil wars in the west and the anti-Americanism in the north, I just would not feel safe.

[xchrom]

12. yeah -- i feel ya. -- i do. nt

[tabatha]

14. Botswana is a very safe place.

[Posteritatis]

19. One of the sanest countries in the region

Especially in their handling of the HIV epidemic, though they've got their act together in general. It's kind of sad considering how utterly hosed they are because of the epidemic though. :/

[tabatha]

4. Here is more info:

http://insciences.org/article.php?article_id=4695

[wtbymark]

6. it's also the area where they found Lucy, is it not? n/t

[struggle4progress]

9. No. Olduvai Gorge in in Tanzania

[struggle4progress]

16. oops! see #15

Prominent Hominid Fossils
http://www.talkorigins.org/faqs/homs/specimen.html

[frogmarch]

15. Lucy was found in Ethiopia

in the Awash Valley of the Afar Depression.

[Zenlitened]

10. We are all African.

We really are one family, the human family. And everyone you meet, anywhere on the planet, is a cousin.

It's kind of an awesome, mind-blowing fact.

And knowing it makes the creationism/intelligent design nonsense all the more repulsive. The facts -- as well as the questions we still haven't answered -- are FAR more wondrous and inspiring than the moldy old fables parroted by religion-pimps.

[Igel]

18. Another article on this that I read made a crucial point.

That they can only know what current gene distributions tell us. We can't know what distributions were 100k years BCE, esp. if the population was fairly thin.

They added something important, however. The San have a fairly complex genetic distribution--it's been assumed for a few years that they're likely to be more similar, in many ways, to early humans, and that other "tribes" branch not from the Africans living in E Africa but from their stock or kindred stock.

It's also fairly certain that the San were eliminated from a fair amount of Africa by the Bantu expansion, which happened fairly late. The assumption was that the people before the Bantu were San, and the linguistic evidence (and maybe some archeological evidence) points this way. The assumption is that the San were as close to indigenous to those areas as any group could be--first settlers, followed by 10s of millennia of isolation in a fair degree of isolation--which would in itself produce a fair amount of genetic diversity.

This study points out that there's a fair genetic/linguistic correlation (most members speaking language X will be identifiably people of ethnicity X). They also point out that most of the language/ethnic groups show considerable mixing ... except one. The Bantu (which is just a language group, and like the linguists' use of "Aryan" not a single ethnicity). However, it's precisely the Bantu who overlay areas that were formerly occupied by the San. So do Bantus actually show significant mixing, but we can't spot it, or did they swamp the local population so that the substratum genetics are hard to spot, or did they simply dispose of the San?

For an example of how the location could be a spurious conclusion, what would happen if more diffuse groups, showing less concentrated genetic diversity, were driven into a much smaller area by another group's expansion? You'd get greater genetic diversity in a small area, and satisfy the criterion for that being the "homeland". As another example, consider what would happen if the Bantu were to (as is happening, for the most part) completely wipe out the San. Suddenly there'd be scant trace of this diversity and suddenly the method used would conclusively point to another place. Since much of the San area *has* been overwritten, we have to simply acknowledge this as a flaw and assume the uncertainty can't be resolved.