Re: Could our big brains come from Neanderthals?


"Spanish Paranoia" <laparanoia@xxxxxxxxx> wrote in message
news:1163157330.628098.22900@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
The study is basically stating that Neanderthal-Cromagnon Hybrides
(i.e. Europeans)

When animal and plant breeders cross different species of plants and
animals the resulting hybrid offspring has qualities and
characteristics possessed by neither parent. This outcome is known as
'hybrid vigor'.
But such vigor does not come along without some nasty side-effects,
because it is also a well-known biological fact that when divergent
species of animals are crossed, the offspring frequently show unstable
behavior derived from the conflicting sets of instincts inherited from
both parents.
And in the case of europeans, that interbreeding between Neanderthal
and Cro-Magnon must have produced two completely different sets of
behavioral patterns, producing much intelligence and confusion in the
offsprings, which led them to conquer the rest of the world, looting it
while at the same time trying to convert the "discovered" natives to
their "True Values and Religion".

BTW, Did you know that most Brits are actually Iberian descendants?
Stranded Iberians, i call them now...

http://groups.google.com/group/alt.usage.spanish/browse_thread/thread/af04eed45d8203f1?hl=en


Roger Bagula wrote:
http://news.yahoo.com/s/nm/20061107/sc_nm/science_neanderthals_dc
Could our big brains come from Neanderthals?

Tue Nov 7, 6:07 PM ET

WASHINGTON (Reuters) - 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.


Doesn't this say that 30% of the human population has inferior brains?
People were moving out of Africa before AMH came in contact with
Neanderthals - they don't have the D allele? What does this mean in terms of
race? And would this give Klein's theory of the great leap that occurred in
the AMH a great leap forward?

Jois


.

Relevant Pages

  • Re: Could our big brains come from Neanderthals?
    ... And in the case of europeans, ... Could our big brains come from Neanderthals? ... variants into the human gene pool that subsequently spread," said Bruce ... "The gene microcephalin regulates brain size during development ...
    (sci.anthropology.paleo)
  • Re: Could our big brains come from Neanderthals?
    ... And in the case of europeans, ... Could our big brains come from Neanderthals? ... variants into the human gene pool that subsequently spread," said Bruce ... "The gene microcephalin regulates brain size during development ...
    (sci.anthropology.paleo)
  • Re: Could our big brains come from Neanderthals?
    ... Could our big brains come from Neanderthals? ... WASHINGTON - Neanderthals may have given the modern humans who ... variants into the human gene pool that subsequently spread," said Bruce ... "The gene microcephalin regulates brain size during development ...
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  • Could our big brains come from Neanderthals?
    ... WASHINGTON - Neanderthals may have given the modern humans who replaced them a priceless gift -- a gene that helped them develop superior brains, ... 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. ...
    (sci.anthropology.paleo)
  • Do our big brains come from Neanderthals?
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