Comments on: Comments on 5206

Post number 5206

lagado — Thu, 11 Jan 2001 04:00:27 -0800

DNA analysis of a 60,000-year-old skeleton from Lake Mungo in Australia throws doubt on the "Out of Africa" theory of human evolution.

By: Postroad

Postroad — Thu, 11 Jan 2001 06:37:48 -0800

I had never accepted the out of Africa thesis, preferring to believe that my ancestors came from New Jersey.

By: mikewas

mikewas — Thu, 11 Jan 2001 08:27:56 -0800

Does this mean I'm no longer an African-American?

By: dhartung

dhartung — Thu, 11 Jan 2001 14:00:10 -0800

Mike, that would be African-Middle-Eastern-European-American, for you and I ... I think for me there's a bit of "Scythian" in there, too.

By: baylink

baylink — Thu, 11 Jan 2001 16:55:38 -0800

Yeah, but did this skeleton have semen in it's anus?

By: lagado

lagado — Thu, 11 Jan 2001 19:29:14 -0800

Perhaps I should have described what the "Out of Africa" theory actually is first. This theory says that all humans on the planet today are descendents from a single group of humans that spread out from Africa around 100,000 years ago. By implication this means that all the other human lineages which had already starting moving from Africa and entering Europe and Asia about 2 million years ago (such as Homo Erectus, Java Man and the Neanderthals) died out and are not our ancestors. The alternative theory called the Multi-regional theory does not rule out the possibility of the human race developing into its anatomically modern form through inter breeding between different human stocks both inside and outside of Africa. Thus, the theory goes, Neanderthals might have been amongst our ancestors. The Out of Africa theory is the preferred explanation although contrary evidence does crop up from time to time. The key evidence for the Out of Africa theory is genetic. It has been found that all humans today (both in Africa and everywhere else) share common a type of DNA (called mitochondrial DNA). This DNA, which only mutates slowly, can be compared between individuals and it is possible to determine how closely related one person is to another. For example, it's possible to determine that Chinese and Irish are more closely related to each other than they are to modern Africans, suggesting that they are descended from a common group that migrated out of Africa. This DNA is also shared by Australian Aborigines and the arrival date of humans in Australia (40 to 60,000 year ago) which is used to calibrate the genetic calculations used to work out when anatomically modern humans first left Africa. The only problem is that the DNA analysis of an ancient skeleton from Lake Mungo in Australia suggests that this undoubtedly modern human did not share the same mitochondrial DNA and comes from an older and distinct lineage. This suggests multiple migrations and a more complex story.

By: dhartung

dhartung — Fri, 12 Jan 2001 01:39:17 -0800

I'm waiting for confirming research. This could be a bit like the Japanese archaeologist who was determined to show Stone Age occupation on the islands to justify Japanese mythology.

By: lagado

lagado — Fri, 12 Jan 2001 04:16:26 -0800

I wouldn't go quite that far, Australian based studies of early humans in the past have been crucial to forming our present understanding. But this certainly needs corroborating evidence. I think that they have found anatomically modern human bones in Israel dating from around 100,000 years old which might be an interesting source of DNA.