Skip to comments.Fresh debate over human origins
Posted on 12/26/2002 8:02:36 AM PST by PatrickHenry
The theory that we are all descended from early humans who left Africa about 100,000 years ago has again been called into question.
US researchers sifting through data from the human genome project say they have uncovered evidence in support of a rival theory.
Most scientists agree with the idea that our ancestors first spread out of Africa about 1.8 million years ago, conquering other lands.
What happened next is more controversial.
The prevailing theory is that a second exodus from Africa replaced all of the local populations, such as Europe's Neanderthals.
Some anthropologists, however, advocate the so-called multiregional theory, that not all the local populations were replaced.
They think some of these ancient people interbred with African hominids, contributing to the gene pool of modern humans.
The new evidence, published online in the Proceedings of the National Academy of Sciences, is based on an analysis of data from the human genome project - the effort to map the entire human genetic blueprint.
Blood and bones
Researchers led by Henry Harpending, professor of anthropology at Utah University, studied small differences in human DNA known as single nucleotide polymorphisms.
Studying when these mutations appeared gives a window into the ancient past, allowing scientists to trace the rise and fall of early humans in different parts of the world.
"The new data seem to suggest that early human pioneers moving out of Africa starting 80,000 years ago did not completely replace local populations in the rest of the world," he says. "There is instead some sign of interbreeding."
The study suggests that there was a bottleneck in the human population when ancestors of modern humans colonised Europe about 40,000 years ago.
This is a puzzle because earlier human genetic studies have backed the idea that a rapidly expanding African population spread globally and replaced all local populations.
One possibility is that there was limited interbreeding between humans migrating from Africa and local populations in Europe and elsewhere.
Commenting on the research, Professor Chris Stringer, Head of Human Origins at London's Natural History Museum, said that in the last few years the multiregional model of human evolution had been called into question by new data, much of it genetic, showing our species had a recent African origin.
He told BBC News Online: "Arguments now centre on whether we are recently and entirely Out of Africa, or just mainly so.
"Some replacement models, and some genetic data, suggest no interbreeding at all with archaic peoples outside of Africa, while other replacement models allow limited interbreeding with the locals over the short time scale in which they overlapped.
"This new research suggests there could have been some interbreeding, but as the authors recognise, it could have been limited, and whether it happened at all is still an open question."
Pay in advance. Cash on the barrelhead. No returns, no exchanges, no warranty. As is, where is. No, the merch may not be examined before purchase. There will no further explanations on this deal.
Sometimes ignorance is bliss.
"But scientists can't bring themselves to face the truth."
"They have become the... priests, bishops and cardinals---of the Age of Secularism."
"They have established themselves in the federally financed temples of the Church of Education, an institution very much like the hierachy of the once-official Church of England. They condemn any faith other than their own. God is heresy to them, and must be expunged from the society. Those who wish to receive a degree must worship only at the alter of "pure" science -- which, by the parameters established by the priests, themselves, cannot answer the most important questions of all.."
450 mg of eskalith CR about eighteen times a days oughta do the trick.
I enjoy getting pinged to these threads...but this is the reason I rarely respond. Not meaning you, of course.
I took a few minutes to decipher that post, and I must say I agree with a lot of what you said.
These were the Classical liberals...founding fathers-PRINCIPLES---stable/SANE scientific reality/society---industrial progress...moral/social character-values(private/personal) GROWTH(limited NON-intrusive PC Govt/religion---schools)!
Where you and I diverge is on the Evolution/Communism thing. You seem to view Darwin and evolution as the beginning of the end for enlighted, moral civilization, while I think Marx, class struggle, and the "dictatorship of the proletariat" are the true dangers.
God bless you, I think we both have a common enemy in the BRAVE-NWO.
452 posted on 9/7/02 8:54 PM Pacific by Dakmar
Super duper helpful! Thanks ever so much.
you have to take off the evo trick glasses---
you've got your 'truth/reality blockers' on too tight!
f., pretty much gobblidegook again here. I'm neither brainwashed, nor tricked, nor blocked from reality as you assert free of corroberation, reason, or logic. You either can't explain yourself, or won't. My mistake, I thought you wanted in on this discussion.
"What men... believe---really does matter."
These out of Africa theories, I suppose, are predicated on a passage through a certain region of the earth, strangely important even today. Plus this is old news even though the source of the doubt may be novel. I wouldn't buy fish from the "fresh" debate BBC.
There were at least three major waves of early human migration out of Africa, our DNA suggests. Apparently the wanderers made love, not war: gene patterns hint that later emigrants bred with residents.
God, by defintion is uncreated, he is the creator, eternal and outside of time. Either you have faith in that or you don't.
Since you don't seem to be a man of faith perhaps you could answer this.
How did nothing without any catalyst result in an ever expanding universe?
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