
Why are Europeans the whitest people on the planet? - martian
http://knol.google.com/k/frank-w-sweet/why-are-europeans-white-e1/k16kl3c2f2au/14
======
crux
Ultimately this is the sort of thing that is utterly fascinating to me, but
since a) it gives me no reason that I _shouldn't_ believe it (corollary:
mentions no competing viewpoints), and b) I have no expertise at all in the
field, I have to assume that I shouldn't go around telling everybody that I
know why Europeans are the whitest people on Earth, just yet.

The one presented fact that I'm _not_ totally solid on is, I'm not sure that
prehistoric and ancient art are sufficiently solid to provide a date by which
we can assume Europeans were white.

~~~
petewarden
The assumption that cave art conventions reflect actual pigmentation is pretty
shaky. The egyptian statue reference is just wrong - there's a long tradition
of females being depicted as yellow or white versus red or brown for males.
This probably has some basis in men engaging in more outdoors activity, but
this art is definitely not a photo-realistic rendering. If you want a modern
analogy, think the Simpsons! Here's some academic work that mentions the
gender conventions:

[http://www.mywire.com/a/Oxford-Encyclopedia-Ancient-
Egypt/Ge...](http://www.mywire.com/a/Oxford-Encyclopedia-Ancient-Egypt/Gender-
Roles/9472049/)

I don't know anything about the other points in the article, but these errors
make me doubt their accuracy.

~~~
herdrick
The redness of men in Egyptian art is based on the fact that men's skin _is_
redder, due to more hemoglobin closer to the surface.

~~~
Tuna-Fish
Another good point is that fairer skin is, and has long been, a sexually
desirable trait. A pharaoh has his pick of anyone he wants.

~~~
kingkawn
Since the European conquest of the planet, the fairer skin preference has been
projected back onto many other groups of people, but is inherently suspicious
given the circumstances within which we've learned about their cultures.

~~~
ksvs
It long predates that. European slave girls (and boys) were particularly
prized in the caliphate when Europe was a backwater.

~~~
Gupie
Historically pale skin was prized because rich women didn't work in the
fields, they stayed in doors out of the sun. Tans came into fashion with air
travel. Only the wealthy could fly to say the Med for their holidays Also I
suppose poor slum dwellers didn't get much sun. They only got rickets due to a
subsequent lack of vitimum D.

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gort
Neither the word "evolution" nor the word "gene" appears in an article that is
clearly about a change in gene frequencies over time caused by natural
selection. Hmm.

(Perhaps the author is trying to avoid the suggestion that white people are
"more highly evolved", which is of course nonsense; it's just different
adaptations suited for different environments.)

[Edit: Yes, this comment is probably stupid.]

~~~
pohl
It does mention adaptation, traits, and survival. He doesn't really need to
put too fine a point on it.

What do you mean by "more highly"?

~~~
gort
It was in scare quotes to indicate that it doesn't really have a clear
scientific meaning.

~~~
camccann
In practice, the meaning of "more highly evolved" is generally something like
"more similar to the person using the phrase".

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bh23ha
I'm not sure what's new here.

We've known for a very long time vitamin D is produced when the skin is
exposed to UV light. We've known how important vitamin D is. Northern Europe
dark and cold, yep we've known that too for a while.

Innuit get their vitamin D from the seafood based diet, we've also known that
too. Northern Europe being unusually warm thanks to the gulf stream, that is
also old news.

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jvdh
[quote] Too much UV penetrating the skin (too pale-skinned under intense
sunlight) increases Vitamin D but reduces folate. Lack of folate causes neural
tube defects in the fetus, causing such congenital abnormalities as
craniorachischisis, anencephalus, and spina bifida, leading to many
miscarriages. [/quote]

So the Europeans had adapted to their environment, changed to a grain diet,
suddenly had too little vitamin D. This would mean they would increase their
vitamin D, but reduces folate, and therefore increase the number of
miscarriages?

Seems like a simple way to test if this hypothesis is actually true. Just look
at some historic numbers of the number of miscarriages with those diagnoses
(these days pregnant women in Europe get folate supplements).

~~~
gojomo
I found the way the folate side of the equation was dropped midway through the
article undermined the story a bit.

Did the grain-eating D-deficient Baltic-dwellers have to do something else to
restore the folate being lost by their lighter pigmentation?

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10ren
Why are humans furless?

I loved the semi-aquatic-ape theory (that in foraging for shellfish we lost
our fur as whales, dophins, hippos did), but I understand that one has fallen
from favour.

~~~
pg
To run down prey without overheating.

~~~
grinich
and here's a bit more detail.

 _Most mammals can sprint faster than humans — having four legs gives them the
advantage. But when it comes to long distances, humans can outrun almost any
animal. Because we cool by sweating rather than panting, we can stay cool at
speeds and distances that would overheat other animals. On a hot day, the two
scientists wrote, a human could even outrun a horse in a 26.2-mile marathon._

from <http://www.nytimes.com/2009/10/27/health/27well.html>

More on the Man vs. Horse Marathon.
<http://en.wikipedia.org/wiki/Man_versus_Horse_Marathon>

~~~
10ren
Ah yes, the persistence hunt: <http://news.ycombinator.com/item?id=557452>

The nightmare concept of a relentless, unstoppable killer (as in zombie movies
and the Terminator) appears to be based on _us_.

Our bipedalism and big brain from a high protein diet also seem related to
this. It seems to have given us our human qualities, yet also feels so very
unrelated to those human qualities.

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mynameishere
Traits tend to go away when not needed. Pigment is essentially an appendix.

EDIT: Okay, wisdom teeth then. Or teeth in general, which are gradually
disappearing.

~~~
thaumaturgy
...in that the appendix was recently discovered to have a useful function as a
backup store for intestinal bacteria in case something killed off all the good
stuff in your gut?

~~~
gort
(Slightly off topic, but isn't the benefit of the appendix outweighed by how
often if becomes infected, etc?)

~~~
pohl
Are we really at liberty to disagree with the replicators on that one? If it
really outweighed it, it would have been the end of the line.

~~~
gort
Removing the appendix would presumably take multiple mutations that would have
other, possibly harmful effects as well. So it can't really happen overnight.

~~~
pohl
In order for it to happen at all the appendix needs to become so troublesome
that everybody dies before they can reproduce. My son was born 3 weeks ago. My
appendix could do me in tomorrow and the genes that express for it will likely
go on.

~~~
gort
_In order for it to happen at all the appendix needs to become so troublesome
that everybody dies before they can reproduce._

Not at all; it just needs to reduce the average number of children the average
person has. Any mutation that makes it "less troublesome" on average would be
favoured.

~~~
lionhearted
> Any mutation that makes it "less troublesome" on average would be favoured.

That's correct, but, from my understanding, revolutionary mutations are orders
of magnitude less likely to happen than evolutionary mutations.

Everyone has an appendix, so there's no natural selection pressure where non-
appendix people are breeding to further the spread of non-appendix humans.
Just thinking out loud here - I reckon the way it would have to go would be if
the appendix was a significant disadvantage, and people with a less
sensitive/smaller/less prominent/something-like-that appendix were able to
survive more easily or have more children on average, then you might selection
pressures moving towards a less prominent and eventually no appendix.

It could happen, but it'd take a long time. Actually, one that fascinates me
is what effect modern medicine and technology will have on evolution. Greater
mobility is seeing children with a more mixed and diverse hereditary mix.
Beyond that though, longer life cycles and better medical treatment might mean
both slower and less evolution. I'd expect a lot of positive effects from
interbreeding of different peoples over the next 500 years, but I reckon,
sadly, that things like aggression won't be genetically bred out of us any
time soon by being selected for less. Interesting stuff to think about.

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Gormo
How does this hypothesis explain pale skin coupled with dark hair, i.e. the
typical Mediterranean phenotype.

~~~
astine
Mediterraneans aren't very 'pale-skinned.' They have a lot more melanin than
you find in say, Sweden.

~~~
mitko
Right! For example, people in Sicily have darker skin.

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tfh
this is the first knol article i find useful :) actually the first i read..

~~~
tfh
why am i being downvoted? I just wanted to say that knol didn't trun out to be
the wikipedia killer as google intended.

~~~
antipaganda
Because your first post turned out content-free, so the downvotes want people
not to bother reading it.

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pbhjpbhj
I live in Europe, UK, and we grow plenty of grains here.

~~~
alexgartrell
Grains are low in Vitamin D, that's why native europeans are pale. Paleness
allows you to absorb more vitamin D from sunlight.

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cool-RR
Maybe it's because they were spending less time in the sun?

Please deliver my Nobel prize in the mail, thanks.

~~~
henrikschroder
If you had actually bothered to read the article, you would have found out
that it's the other way around. White people have less pigment to maximize the
amount of vitamin D that can be synthesized given the little sunlight they
receive.

