Posted on 11/07/2006 7:27:55 PM PST by Pharmboy
Neanderthals may have given the modern humans who replaced them a priceless gift -- a gene that helped them develop superior brains, U.S. researchers reported on Tuesday.
And the only way they could have provided that gift would have been by interbreeding, the team at the Howard Hughes Medical Institute and the University of Chicago said.
Their study, published in the Proceedings of the National Academy of Sciences, provides indirect evidence that modern Homo sapiens and so-called Neanderthals interbred at some point when they lived side by side in Europe.
"Finding evidence of mixing is not all that surprising. But our study demonstrates the possibility that interbreeding contributed advantageous variants into the human gene pool that subsequently spread," said Bruce Lahn, a Howard Hughes Medical Institute researcher at the University of Chicago who led the study.
Scientists have been debating whether Neanderthals, who died out about 35,000 years ago, ever bred with modern Homo sapiens. Neanderthals are considered more primitive, with robust bones but a smaller intellects than modern humans.
Lahn's team found a brain gene that appears to have entered the human lineage about 1.1 million years ago, and that has a modern form, or allele, that appeared about 37,000 years ago -- right before Neanderthals became extinct.
"The gene microcephalin (MCPH1) regulates brain size during development and has experienced positive selection in the lineage leading to Homo sapiens," the researchers wrote.
Positive selection means the gene conferred some sort of advantage, so that people who had it were more likely to have descendants than people who did not. Lahn's team estimated that 70 percent of all living humans have this type D variant of the gene.
"By no means do these findings constitute definitive proof that a Neanderthal was the source of the original copy of the D allele. However, our evidence shows that it is one of the best candidates," Lahn said.
The researchers reached their conclusions by doing a statistical analysis of the DNA sequence of microcephalin, which is known to play a role in regulating brain size in humans. Mutations in the human gene cause development of a much smaller brain, a condition called microcephaly.
By tracking smaller, more regular mutations, the researchers could look at DNA'S "genetic clock" and date the original genetic variant to 37,000 years ago.
They noted that this D allele is very common in Europe, where Neanderthals lived, and more rare in Africa, where they did not. Lahn said it is not yet clear what advantage the D allele gives the human brain.
"The D alleles may not even change brain size; they may only make the brain a bit more efficient if it indeed affects brain function," Lahn said.
Now his team is looking for evidence of Neanderthal origin for other human genes.
One point I would make is that before Neanderthalensis and Sapiens became separate species, they could then have had common ancestors.
A mixing and contest for beneficial genes could have resulted from that.
So now there is evidence that early Homo sapiens shaved and showered regularly?
The Neandertal EnigmaFrayer's own reading of the record reveals a number of overlooked traits that clearly and specifically link the Neandertals to the Cro-Magnons. One such trait is the shape of the opening of the nerve canal in the lower jaw, a spot where dentists often give a pain-blocking injection. In many Neandertal, the upper portion of the opening is covered by a broad bony ridge, a curious feature also carried by a significant number of Cro-Magnons. But none of the alleged 'ancestors of us all' fossils from Africa have it, and it is extremely rare in modern people outside Europe." [pp 126-127]
by James Shreeve
They also may be responsible for the Democrat Party.Hey, don't insult the Neanderthals. :') Thanks Pharmboy.
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Maybe I will live long enough to see the false "Neanderthal" classification to go by the wayside and the various scientific disciplines realize we are just talking about homo sapiens, just homo sapiens....
Ugh. They are both homo sapiens. Neanderthalis is a false classification whose origin is in that same school that gave the world Nazi science.
btt
It is all in the matter of how they are used. Considering this election, there wasn't much usage going on.
...if you're a redhead.
Redheads 'are neanderthal'
http://www.freerepublic.com/forum/a3adc5573604d.htm
London - Red hair may be the genetic legacy of Neanderthals...
http://www.freerepublic.com/focus/f-news/1322006/posts
Beat me to it.
The answer is no. Apes, monkeys, and hominids are one family of creatures, we are another; we are not related to them at all other possibly than for similarity of design. The neanderthal has been ruled out as a plausible ancestor for modern man and his DNA described as "about halfway between ours and that of a chimpanzee" and all other hominids are further removed from us THAN the neanderthal. There is thus no plausible ancestor for modern man amongst the hominids. To be descended from something, at some point, you have to be able to interbreed with the something and we could no more interbreed with neanderthals, much less any other hominid, than we could with goats or horses.
The results seem consistent with the theory that man has and is getting dumber not smarter. This definitely seems true at least in some aspects.
Uh...no.
As Chico might say, why a duck?
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