Why are Europeans the whitest people on the planet?(knol.google.com)
knol.google.com
Why are Europeans the whitest people on the planet?
http://knol.google.com/k/frank-w-sweet/why-are-europeans-white-e1/k16kl3c2f2au/14
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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...
I don't know anything about the other points in the article, but these errors make me doubt their accuracy.
http://www.mywire.com/a/Oxford-Encyclopedia-Ancient-Egypt/Ge...
I don't know anything about the other points in the article, but these errors make me doubt their accuracy.
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.
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.
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.
It long predates that. European slave girls (and boys) were particularly prized in the caliphate when Europe was a backwater.
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.
[deleted]
The article as posted references a more scholarly presentation of the same material: http://backintyme.com/essays/?p=4
(Note that I have not read this version, nor have I looked at any of the references he's provided - I just noticed the link and briefly scanned through the page)
(Note that I have not read this version, nor have I looked at any of the references he's provided - I just noticed the link and briefly scanned through the page)
(Re note: a good reason, therefore, to publish a mainstream-style article alongside the academic paper?)
It would appear the author is an amateur scholar; he provided a very interesting point of view and I enjoyed the read. It would have been comprehensive had he supplied opposing arguments, references, and fleshed out his writing a bit more.
The Wikipedia page on the topic suggests that chimpanzees have pale skin under dark hair and that humans might have evolved sweat glands and less hair for heat management related to a larger brain. Seemed to me that the suggestion there is that paler ancestors became darker in regions closer to the equator (Africa, Australia, Indonesia).
I guess paler people today in Northern Europe may have either had ancestors who became darker and then lightened (as per the Knol piece) or moved out of Africa before their skin darkened to deal with the UV/Vitamin D issue. From memory, it's been suggested that expansion into Europe was around 50,000 years ago.
Interesting story though - have never read a page on Knol before.
I guess paler people today in Northern Europe may have either had ancestors who became darker and then lightened (as per the Knol piece) or moved out of Africa before their skin darkened to deal with the UV/Vitamin D issue. From memory, it's been suggested that expansion into Europe was around 50,000 years ago.
Interesting story though - have never read a page on Knol before.
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.]
(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.]
Probably because the basis for the article is anthropology not genetics.
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"?
What do you mean by "more highly"?
The article posits that a physical feature can be shaped evolutionarily by environment. Observations of other species appear to support that. We see today that there are different distinctive physical features for people around the globe, so it might be fair to suppose other features may have come about with environmental influence
(even if we haven't yet found correlations). Yet, we also know that the human skull has evolved to change over many years, but if we were to compare the skulls of people across the globe today my guess would be that they are quite similar. Therefore, I think a more accurate assumption would be that modern day humans across the globe have "differently evolved" in some aspects, such as physical appearance.
Well, he spends quite enough time talking about genealogical adaptation to environmental pressures. Are you concerned that he's not being sufficiently clearly anti-creationist?
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.
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.
[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).
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).
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?
Did the grain-eating D-deficient Baltic-dwellers have to do something else to restore the folate being lost by their lighter pigmentation?
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.
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.
To run down prey without overheating.
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
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
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.
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.
They should make it fair and have the runners carry a horse.
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.
EDIT: Okay, wisdom teeth then. Or teeth in general, which are gradually disappearing.
...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?
(Slightly off topic, but isn't the benefit of the appendix outweighed by how often if becomes infected, etc?)
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.
Removing the appendix would presumably take multiple mutations that would have other, possibly harmful effects as well. So it can't really happen overnight.
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.
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.
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.
> 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.
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.
Fair point. I thought it would be fun to compare the mortality rate with an issue with another organ that has slim chance of going away: the pancreas. It looks like the appendix is more-or-less a trouble-free organ in comparison. I wouldn't place any bets on the emergence of an appendix-free homo sapien offshoot any time soon.
http://www.wolframalpha.com/input/?i=pancreas+cancer http://www.wolframalpha.com/input/?i=appendicitis
http://www.wolframalpha.com/input/?i=pancreas+cancer http://www.wolframalpha.com/input/?i=appendicitis
Not if your not being there reduces your son's chances of growing to reproductive age...
Only with the "western" diet. You'll see much fewer cases of appendicitis amongst those who don't eat the overly-rich western diet. So in my opinion, this is cultural, not genetic.
My father had appendicitis before the age of 25, despite a relatively simple diet. His father, who lived through WWII food rationing, had appendicitis, too. He wouldn't have survived without being cut open and treated with penicillin. For obvious reasons, I wish this were caused by culture, but genetics is almost certainly at work.
Culture saved them in this case.
I doubt it; isn't it providing protection from UV-caused skin cancer and such?
[Edit: I took you to mean that pigment was generally not beneficial, but probably you meant only in certain environments, which would be fair enough.]
[Edit: I took you to mean that pigment was generally not beneficial, but probably you meant only in certain environments, which would be fair enough.]
Actually you have it backwards. Melanin is considered extremely important by the body, some people have high latent melanin levels but all people regardless of race are able to darken their skin color via tanning (exposure to the sun triggering melanin release). Darker skin protects you from being sun burned, which is harmful and can even be fatal (leading to heat exhaustion, heat stroke, etc.) The body considers melanin production so important that some of the natural checks and balances against cancer are inhibited in melanin generation cells, which is why skin cancer is fairly common compared to other types of cancer.
Quite. Folks with the recessive MC1R gene for red hair, like myself, are at much higher risk for skin cancer since we don't really tan, only freckle. Interestingly, this gene is also linked to a vitamin K deficiency, lower tolerance for thermal pain and has implications for anaesthesia and post-operative pain management.
Inexplicably it also correlates with a higher tolerance for electrical pain, which might be a useful adaptation for hackers :)
Inexplicably it also correlates with a higher tolerance for electrical pain, which might be a useful adaptation for hackers :)
I don't know where I heard or read this, wearing sunglasses tricks your body into thinking it is dark (no surprise).
In response to that, your thymus (?) which is influenced by light levels now diminished because you covered your eyes with dark glass, releases less melanin which makes your skin more susceptible to UV light. It's weird, your skin is more likely to burn because you are wearing sunglasses.
I believe it was CBC Radio quirks and Quarks where I heard it.
Also, (I mentioned over at Reddit) another interesting thing is the ability of the majority (95%) of adult northern Europeans to be able to digest milk. the next closest group are people from India where 50% of adults are able to digest milk.
In response to that, your thymus (?) which is influenced by light levels now diminished because you covered your eyes with dark glass, releases less melanin which makes your skin more susceptible to UV light. It's weird, your skin is more likely to burn because you are wearing sunglasses.
I believe it was CBC Radio quirks and Quarks where I heard it.
Also, (I mentioned over at Reddit) another interesting thing is the ability of the majority (95%) of adult northern Europeans to be able to digest milk. the next closest group are people from India where 50% of adults are able to digest milk.
In my defense:
"Melanin helps protect the skin against effects of the sun such as skin cancers and premature aging. In African American skin, melanin provides a sun protection factor (SPF) approximately equivalent to 13.4, compared to 3.4 in white skin. This discrepancy illustrates why skin cancer is more prevalent in Caucasian people"
http://www.skincancer.org/skin-cancer-and-skin-of-color.html
"Melanin helps protect the skin against effects of the sun such as skin cancers and premature aging. In African American skin, melanin provides a sun protection factor (SPF) approximately equivalent to 13.4, compared to 3.4 in white skin. This discrepancy illustrates why skin cancer is more prevalent in Caucasian people"
http://www.skincancer.org/skin-cancer-and-skin-of-color.html
Other way around. Darker skin in North America is correlated to more cancer, due to the consequent vitamin D deficiency.
Most of the population is now vitamin D deficient because people don't spend much time outside.
Most of the population is now vitamin D deficient because people don't spend much time outside.
I said specifically skin cancer. Naturally there's a balance between getting vitamin D and avoiding harmful UV. So the best skin tone to have differs in different environments (hence the gradual cline in skin tones over the world).
I don't have details at hand to cite, but I recall encountering some recent news of research that may place in question equating a simple measure of sun exposure to elevated risk for skin cancer. (I didn't look at in depth, and my memory could be somewhat faulty.)
It may not be simple quantity of exposure, but rather severe sunburns that most elevate risk. If one is outside regularly and acclimatized, these severe burns are less likely to occur.
Perhaps someone else will have a more detailed comment on this.
Of course, one's pigmentation will also influence the likelihood of sunburn, although dark pigmentation does not entirely prevent burning.
EDIT: Just read InclinedPlane's comment, above, which mentions the same concern with sunburn.
It may not be simple quantity of exposure, but rather severe sunburns that most elevate risk. If one is outside regularly and acclimatized, these severe burns are less likely to occur.
Perhaps someone else will have a more detailed comment on this.
Of course, one's pigmentation will also influence the likelihood of sunburn, although dark pigmentation does not entirely prevent burning.
EDIT: Just read InclinedPlane's comment, above, which mentions the same concern with sunburn.
[deleted]
How does this hypothesis explain pale skin coupled with dark hair, i.e. the typical Mediterranean phenotype.
this is the first knol article i find useful :) actually the first i read..
why am i being downvoted? I just wanted to say that knol didn't trun out to be the wikipedia killer as google intended.
Because your first post turned out content-free, so the downvotes want people not to bother reading it.
I live in Europe, UK, and we grow plenty of grains here.
Grains are low in Vitamin D, that's why native europeans are pale. Paleness allows you to absorb more vitamin D from sunlight.
Maybe it's because they were spending less time in the sun?
Please deliver my Nobel prize in the mail, thanks.
Please deliver my Nobel prize in the mail, thanks.
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.
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.