Two hundred become five billion

[GeneW]

Due to some mathematical tricks some geneticists have figured out that the entire population of human beings whose ancestors are not from African since this tribe hit the road are descended from just 200 people.

"While there are 14 ancestral populations in Africa itself, just one seems to have survived outside of the continent.

The latest genetic research has shown that it was not until around 70,000 years ago that humans were able to take advantage of falling sea levels to cross into Arabia at the mouth of the Red Sea, which is now known as the Gate of Grief.

It has long been assumed that humans success in spreading around the world was due to their adaptability and hunting skills. The latest research, however, suggests that the very early human pioneers who ventured out of Africa owe far more of their success to luck and favourable changes in climate change than had previously been realised.

Dr Stephen Oppenheimer, a geneticist at the school of anthropology at Oxford University who has also led research on the genetic origins of humans outside Africa, said: "What you can see from the DNA of all non Africans is that they all belong to one tiny African branch that came across the Red Sea.

"If it was easy to get out of Africa we would have seen multiple African lineages in the DNA of non-Africans but that there was only one successful exit suggests it must have been very tough to get out. It was much drier and colder then."

Within around 5,000 years some of these early human pioneers had managed to spread along the edge of the Indian Ocean and down through south east Asia and arriving in Australia around 65,000 years ago.

Others made their way north through the Middle East and Pakistan to reach central Asia.

Around 50,000 years ago they also began spreading into Europe via the Bosporus at the Istanbul Strait. Again low sea levels allowed them to almost walk into Europe.

Dr Alice Roberts, an anatomist at Bristol University who presents The Incredible Human Journey, said: "There seems to have been a huge amount of luck involved as they were totally at the whim of the climate. The climate changed at just the right time to allow them to expand out of Africa and they were allowed to expand geographically as a result, but when the climate changed they shrank back again."

The idea that all non-African humans are descended from a single group of individuals contradicts previous theories that the different modern races evolved seperately from an earlier human ancestor known as Homo erectus in different parts of the world.

Archaeologists in China, for example, believe they have strong evidence that the Chinese evolved directly from a lineage of Homo erectus that arrived in China 2 million years ago and not from African Homo sapiens.

But recent genetic work at Fudan University in Shanghai tested the Y chromosomes of more than 12,000 men currently living in different parts of China and found that they all descended from the original African humans.

Professor Li Jin, a geneticist at Fudan University in Shanghai whose laboratory carried out the research, said: “We did not find a single individual that could be considered the decendants of homo erectus in China.

“I think we should all be happy with that, as afterall, it means that people from all over the world are not all that different from each other.”

http://www.telegraph.co.uk/sciencean...the-world.html

Two hundred people.... to 5,000,000,000 people.

Gene