
Humans evolving 100 times faster than historical levels. - danteembermage
http://www.latimes.com/news/science/la-sci-evolution11dec11,0,5882337.story
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BRadmin
"Nobody 10,000 years ago had blue eyes," Hawks said. "Why is it that blue-eyed
people had a 5% advantage in reproducing compared to non-blue-eyed people? I
have no idea."

Now that's interesting. Any theories?

~~~
tyn
You could just attribute it to the attractiveness of blue eyes. Most people
consider blue (and green) eyes more beautiful than eyes with a different
color. But this will get you only as far as the next inevitable question: why
are blue eyes attractive?

~~~
rsheridan6
Children are have lighter eyes (and everything else) than adults. It's a sign
of youth.

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joubert
Huh? Are you saying Blue is a lighter shade of Brown?

~~~
mmt
Yes, if by "shade" you mean the color progression that human (and other
mammals') eyes make in their development.

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joubert
But your eyes don't change from blue to brown as they develop, or do they?

~~~
elemenohpee
yep:<http://chemistry.about.com/cs/howthingswork/f/eyecolor.htm>)

~~~
joubert
Wow; didn't know this. Very cool. Thanks.

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skushch
The actual article
[http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pub...](http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=18087044)

Greater population = greater opportunity for mutation. Sounds right...

~~~
tokenadult
Thanks for posting the link to the published study, as I was about to. I see
both the study and the submitted news article about it are more than two years
old.

After edit: Here is a link to a more recent article on a closely related
subject:

[http://pritch.bsd.uchicago.edu/publications/pdfs/CoopEtAl09....](http://pritch.bsd.uchicago.edu/publications/pdfs/CoopEtAl09.pdf)

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dkarl
_Races as we know them today didn't exist until fewer than 20,000 years ago,
when genes involved in skin pigmentation emerged, Hawks said._

1) This blows my mind -- am I reading it right that there was virtually no
variation in skin color 20,000 years ago? I assumed there was always variation
in skin pigmentation, with darker skin colors predominating until we expanded
into northern latitudes where lighter colors made sense.

2) What about Neandertals? I always imagined them being light-skinned, since
they were adapted to northern climates. I wonder if they evolved genes for
light skin tens of thousands of years before modern humans did. If so, that
must have made them look even more freakish to modern human eyes, and vice-
versa.

~~~
tokenadult
_am I reading it right that there was virtually no variation in skin color
20,000 years ago?_

I think the correct statement is as you say in another part of your post:
there has always been variation in skin color in the human population. It was
geographically segregated (forming "races" in the biological sense) only very
recently. And even today there is a lot of variation among individuals in skin
color within each continental subpopulation of human beings.

The usual view of evolution of skin color is that the ancestral condition was
white skin under dark hair (as we still see in chimpanzees). Then at some
unknown time, human ancestors became less hairy, and darker skin pigmentation
became necessary. Then as human beings (Homo sapiens) migrated to latitudes
with less sunlight (VERY recently) gene frequencies changed again in favor of
lighter skin in some areas. (Inuit people are quite dark skinned for people
who live near the North Pole and usually wear heavy clothing.)

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darkxanthos
"evolving 100 faster"

100 what?! You're making my brain frustrated.

EDIT: Ahh FTA: 100 times historical levels.

~~~
danteembermage
FTFY, thanks.

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pmichaud
I was confused by the part that said white skin allows more sun light to be
absorbed. I'm quite sure this is wrong:

Dark skin means more light is absorbed, and therefore doesn't bounce back at
the viewer's eyes.

the only explanation I can think of is that the rules are somehow different
for light outside the visible range?

~~~
pedermoeller
As I remember the explanation: Dark skin means more melanin in the skin.
Melanin blocks the UV light that the body uses to synthesize D vitamin. So
white people in north are better suited for utilizing the scarce sunlight for
D vitamin production and black people in the south are better protected
against the skin cancer risk caused by the UV radiation.

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igrekel
Anyone has real details on how they actually date the origin of the presence
of DNA sequences? I sure have my own uneducated guesses but I'd be curious to
know. Or even better find a reference to the explanation.

~~~
req2
[http://findarticles.com/p/articles/mi_m1200/is_n4_v148/ai_17...](http://findarticles.com/p/articles/mi_m1200/is_n4_v148/ai_17352488/)

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daniel-cussen
Evolution works in spurts. We are spurt of evolution as long as our
environment is changing, which it has constantly been for the last 40,000
years.

~~~
joubert
According to Gould (a paleontologist).

Dawkins, with his gene-centered view of Darwinian evolution, refutes this,
explaining that evolution by natural selection is gradual.

~~~
daniel-cussen
>Dawkins, with his gene-centered view of Darwinian evolution, refutes this,
explaining that evolution by natural selection is gradual.

People say he refutes this. According to him, he never said anything to refute
this. In either case, you have to be specific about what "gradual" means.
Dawkin's evolution is more gradual than intelligent design, but not so gradual
that it is inconsistent with Stephen Gould's claim.

~~~
joubert
Dawkins is skeptical of non-adaptive processes in evolution and of natural
selection above that of the gene (i.e. at the organism or even species level).

I'm not implying that they have a hostile personal relationship, but their
academic disagreements were significant. Examples include the gradual view of
evolution, and also Gould's claim of NOMA, which Dawkins (detests).

~~~
berntb
This was settled a long time ago -- outside the popular writing.

<http://cogweb.ucla.edu/Debate/CEP_Gould.html>

(I have studied some related subjects but not evolutionary biology, so I don't
really know the research papers. But I _do_ know that political/religious
idealists are often dishonest to influence public opinion.)

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timwiseman
Interesting article.

One thing to remember is that evolution != progress

~~~
joubert
But survival is good.

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thras
Hawks has a great blog at <http://johnhawks.net/>

And Cochran and Harpending, the "Utah colleagues" mentioned in the article,
have already written a book about this accelerated human evolution:
[http://www.amazon.com/000-Year-Explosion-Civilization-
Accele...](http://www.amazon.com/000-Year-Explosion-Civilization-
Accelerated/dp/0465002218)

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chasingsparks
I find this odd because I have "been around the world and found, that only
stupid people are breeding."

(Pure joke)

