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.
'Open question'
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."
The evidence denies the above. Both archaeological and DNA evidence - from actual DNA found in three separate locations - shows that our closest possible ancestors - the Neanderthals - could in no way have intermixed with Homo Sapiens and produced viable offspring. What we have here is much nonsense from the evolutionists trying to talk away the facts.
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.
The above shows it to be total nonsense. There is no reference point. The only non Homo-Sapiens DNA that has been found is from Neanderthals and that one has been shown to be too far from ours for any intermixing or any ancestor/descendant relationship to have been possible. This is junk science - just like most of the garbage written by evolutionists.
LOL
I'm always amazed at the responses on the evo threads.
And yet the professionals -- the guys who actually know what they are talking about and do the actual work -- don't think the evidence denies it. It's a wonder you're even on this thread, as neither side being debated assumes the validity of Biblical creation or ID and are approaching the problem from a purely scientific point of view.
Ah; that explains my latent fear of small dishes filled with warm butter....
At least a year ago, I posted a scenario where a ship of interstellar castaways ends up the "adam & eve" of their world, and their distant descendants (ignorant of their origins) try to figure it all out. As soon as they realize that they are related to nothing on their world, they would conclude either that they were castaways, or that they were magically created in situ. But we don't have that problem. Everywhere we look we see that we are part of a great inter-related web of life on Earth.
You've hit on the route problem in discussing religion with supernaturalists.
They don't believe you can be a conservative,
unless you've bought in their particular supernatualist belief system.
Naturalists on the other hand believe supernatualists can't be real conservatives since they've demonstrated a belief in magic, (a liberal trait.)
It's really a waste of time even trying to carry on a conversation between the two groups, as there is no common ground..
Does this mean if someone believes in Evolution (Or at least the possibility of the theory) that they're a "Left Winger"?
The answer, as I learned in Catholic school is, "He always was, is, and always will be". He has no beginning and no end.
I always thought that was a pretty convenient answer myself. Of course I guess they call it "Faith" for a reason. (But don't say that to a fundementalist, it makes them mad!!)
Hmm. Just for the sake of debate, it could be argued that any creature, anywhere in the universe, has developed from a DNA infrastructure; that reproductive life in an atmosphere such as earth's can only exist with a DNA genetic structure. Furthermore, with all of the thousands of physical constructs observable, either past or present, on this planet, the most sentient, clever and creative construct is that of the hominid. The best of that group is homo sapiens sapiens.
Therefore, one could argue that no matter where the planet is in the universe, if it has the same elements and atmospere available, life development will be similar genetically.
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