African tribe populated rest of the world

[dreamdancer 0]

found this interesting

Quote

The entire human race outside Africa owes its existence to the survival of a single tribe of around 200 people who crossed the Red Sea 70,000 years ago, scientists have discovered.

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.

Once there they will have encountered Neanderthals, who, with bigger bodies were more adapted to the cold weather at the time, had been living in Europe for nearly a quarter of a million years but are thought to have died out due to changes in the climate.

By 25,000 years ago humans had spread into northern Europe and Siberia and then walked across the Bering land bridge into Alaska around 20,000 years ago.

The peak of the last ice age, which was reached around 19,000 years ago, saw human populations pushed south by the extreme cold and it was about 15,000 years ago that South America became the last continent on the planet to be colonised.

Britain and northern Scandinavia is thought to have been recolonised by modern humans after the last ice age between 10,000 and 8,000 years ago.

Dr Alice Roberts, an anatomist at Bristol University, 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."

http://www.telegraph.co.uk/scienceandtechnology/science/sciencenews/5299351/African-tribe-populated-rest-of-the-world.html

stay away from moving propellers - they bite
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[shropshire 0]

It was an interesting program (should be a good series) and it doesn't hurt that she is cute.



I think that it's still a bit strong to say that they "discovered" that the non-African human race came from the group of around 200... it's still just a theory. The evidence that they have, may point that way for now, but it's difficult to prove conclusively.

(.)Y(.)
Chivalry is not dead; it only sleeps for want of work to do. - Jerome K Jerome

[jclalor 12]

An interesting show on PBS last week about the book, Guns Germs and steel followed up a bit on this and why people in sub Saharan Africa and other areas of the world would be dominated by Europe and parts of Asia.

About the show from Wikipedia,


According to the author, an alternative title would be A short history about everyone for the last 13,000 years.[1] But the book is not merely an account of the past; it attempts to explain why Eurasian civilizations, as a whole, have survived and conquered others, while attempting to refute the belief that Eurasian hegemony is due to any form of Eurasian intellectual, moral, or inherent genetic superiority. Diamond argues that: the gaps in power and technology between human societies originate in environmental differences amplified by various positive feedback loops; and that, if cultural or genetic differences have favored Eurasians (for example Chinese centralized government, or improved disease resistance among Eurasians), it is only so because of the influence of geography.

Diamond points out that nearly all of humanity's achievements (scientific, artistic, architectural, political, etc.) have all occurred on the Eurasian continent, while the peoples of other continents (Sub-Saharan Africans, Native Americans, and Aboriginal Australians/New Guineans) have been largely conquered, displaced, and in some extreme cases--referring to Native Americans, Aboriginal Australians, and South Africa's indigenous Khoisan peoples--were exterminated by Eurasian military and political advantages stemming from the early rise of agriculture after the last Ice Age. He proposes explanations to account for such disproportionate and lopsided distributions of power and achievements in history.

The book's title is a reference to the means by which European nations conquered populations of other areas and maintained their dominance, often despite being vastly out-numbered - superior weapons provided immediate military superiority (guns), European diseases weakened the local populations and thus made it easier to maintain control over them (germs), and centralized governmental systems promoted nationalism and powerful military organizations (steel). Hence the book attempts to explain, mainly by geographical factors, why Europeans had such superior military technology and why diseases to which Europeans were immune devastated conquered populations.

Diamond highlights two major environmental advantages of Eurasia over other areas in which farming apparently developed independently. The various Eurasian inventors of farming, and especially those in "South West Asia" (roughly Mesopotamia and Turkey) had by far the best natural endowment of crops and of domesticable animals in the size range from goats or dogs upwards - the superiority in domesticable animals was the more extreme, as other areas had at most two and often none. Eurasia's other big advantage is that its mainly East-West axis provides a huge area with similar latitudes and therefore climates. As a result it was far easier for migrating Eurasian populations to use in their new homes the plants and animals to which they had become accustomed; by contrast the Americas' North-South axis forced migrating Native Americans to adopt new crops and, where available, animals because they found a wide variation in climates as they migrated from North to South.

Native Americans, for instance, had access to corn. But corn provides little nutrients and must be planted one by one--an extremely cumbersome task. On the other hand, Eurasians had wheat and barley, high in fiber and nutrients, and which can be spread en masse with just a toss of the hand, capable therefore of generating massive food surplus, and thus exponential population growth--which led to larger workforces, inventors, artisans, etc. (as well as the origins of inequality and social injustice itself). Grains are not only easily planted, but can also be stored for longer periods of time, unlike bananas (a tropical fruit) for instance. Furthermore, Sub-Saharan Africans had access to mostly wild mammals, whereas Eurasians had access to the most docile animals on the planet: horses and camels that are easily tamed for human transportation; goats and sheep for hides, clothing, and cheese; cows for milk; bullocks for tilling fields and transportation; and benign animals such as pigs and chickens. Africans, on the other hand, through geographic mischance, had to deal with lions, leopards, etc. So Eurasia was merely the beneficiary of geographic, climatic, and environmental happenstance that favored them after the last Ice Age about 13,000-15,000 years ago. Diamond points out that the only animals useful for human survival and purposes in New Guinea actually came from the East Asian mainland, when it was transplanted there during the Austronesian invasion some 4,000-5,000 years ago.

Diamond also touches very briefly on why the dominant powers of the last 500 years have been West European rather than East Asian (especially China). The Asian areas in which major civilizations arose had geographical features conducive to the formation of large, stable, isolated empires which faced no external pressure to correct policies that led to stagnation. On the other hand Europe's many natural barriers divided it into competing nation-states and this competition forced the European nations to encourage innovation and avoid technological stagnation.[1]

The book has met with several criticisms, even from reviewers who are sympathetic to its aims and approach. Diamond attempted to anticipate some of these in the book and has answered some of them more recently.

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[pirana 0]

The patterns of expansion and migration have been pretty well understood for several decades, with DNA now having confirmed what was understood from archaeological evidence and nicely filling in the details.

What I find strange is the claim that only 200 humans made the migration. Have to check it out and see why they make that claim.

The claim that "the timing was just right" is wierd too. I'd say that early human migrations were of course limited by climate; but that statement makes it sound like they had a migration plan, a scheduled departure window, and the climate changed just in time for it to be successful.

"Oh dear, if this ice sheet doesn't retreat soon we're never going to make the 6:10 to Kensington."

" . . . the lust for power can be just as completely satisfied by suggesting people into loving their servitude as by flogging them and kicking them into obedience." -- Aldous Huxley

[shropshire 0]

Quote

The claim that "the timing was just right" is wierd too. I'd say that early human migrations were of course limited by climate; but that statement makes it sound like they had a migration plan, a scheduled departure window, and the climate changed just in time for it to be successful.

"Oh dear, if this ice sheet doesn't retreat soon we're never going to make the 6:10 to Kensington."

The T.V program emphasis was not on a planned departure, but more an opportunity that arose from the Greening of the Sahara and reduction of sea levels over to Arabia and the presence of fresh water along the southern coast enabling expansion East.

(.)Y(.)
Chivalry is not dead; it only sleeps for want of work to do. - Jerome K Jerome

[pirana 0]

Then they should have said the circumstances were right, not the timing. They were only reacting to their circumstances, not waiting for the right timing.

Nit picky? Yes; but I expect professionals to get it right.

" . . . the lust for power can be just as completely satisfied by suggesting people into loving their servitude as by flogging them and kicking them into obedience." -- Aldous Huxley