Posted on 12/15/2005 10:05:07 PM PST by RWR8189
Scientists said yesterday that they have discovered a tiny genetic mutation that largely explains the first appearance of white skin in humans tens of thousands of years ago, a finding that helps solve one of biology's most enduring mysteries and illuminates one of humanity's greatest sources of strife.
The work suggests that the skin-whitening mutation occurred by chance in a single individual after the first human exodus from Africa, when all people were brown-skinned. That person's offspring apparently thrived as humans moved northward into what is now Europe, helping to give rise to the lightest of the world's races.
Leaders of the study, at Penn State University, warned against interpreting the finding as a discovery of "the race gene." Race is a vaguely defined biological, social and political concept, they noted, and skin color is only part of what race is -- and is not.
In fact, several scientists said, the new work shows just how small a biological difference is reflected by skin color. The newly found mutation involves a change of just one letter of DNA code out of the 3.1 billion letters in the human genome -- the complete instructions for making a human being.
"It's a major finding in a very sensitive area," said Stephen Oppenheimer, an expert in anthropological genetics at Oxford University, who was not involved in the work. "Almost all the differences used to differentiate populations from around the world really are skin deep."
(Excerpt) Read more at washingtonpost.com ...
Can they even talk about this? Sounds like the ultimate violation of pc.
The wording in the article seems to place the blame squarely on the appearance of white skin color.
Ethnic hatred (which is what is usually meant by the usually-inaccurate term "racism") doesn't require differences in pigmentation.
Well, that would do it, since black skin color didn't appear, but was likely there to begin with.
Ethnic hatred (which is what is usually meant by the usually-inaccurate term "racism") doesn't require differences in pigmentation.
No it doesn't, but pigmentation differences certainly help.
Which, of course, explains the Inuit perfectly.
It's obvious: Making me brownies.
Yeah, because we all know that pale-skinned humans would never think to wear clothing to shield them from the sun.
Adaptation is a variation within a species. The extrapolation is that this variation will also produce new species with completely different genetic information given enough time.
The extrapolation relies on inference from indirect evidence.
The extrapolation is challenged by the up and coming mathematics of information theory. One of the fascinating tenets of that theory is that information is independent of the carrier of that information. In other words, DNA, in and of itself is nothing magical or special; it's simply the carrier of the information.
You can do some interesting experiments based on this. By treating evolution in terms of information, you can create computer simulations that can test to see if information can be added to an information matrix through random copying errors. This is the fundamental test of evolution (because a mutation doesn't count unless it is passed on to the offspring). If you cannot add information, then the creation of species with entirely new morphologies and biochemistries is impossible, and the extrapolation that variation within an information matrix equals creation of new information matrices (the creation of new species by an extrapolation of variation within a species) is proven wrong.
One of the finest examples of circular logic I have seen in quite a while.
Translation: Sunlight selects for skin darkening. Except where it doesn't.
I heard this textbook explanation in my Human Anthropology class, too, and my first question to the teacher was: "What, only Eskimos eat fish?
Flaw #1. Clothing protects from sunlight.
Flaw #2: Anyone can eat fish and animal organ meats at any latitude, but more commonly at northern lattitudes where such food is easier to obtain than growing or foraging for plants. Therefore, there is no advantage to a lighter skin because diet compensates.
The reality is, we really don't know what selected for White skin in higher latitudes. The scientists discovering the gene frankly admit as much in their article.
Peoples in the far north cannot lighten the skin enough to get vitamin D because that skin would promptly freeze.
They supplement with fish oils. If I remember correctly, cold-water fish are the kind needed.
Because of this, their skin is not forced to lighten for production of vitamin D. Their skin color is closer to the world-average brown.
Ring species are a fascinating example of how geographic isolation and inbreeding can force the expression of dormant or recessive genetic traits in an organism, and cause loss of genetic information to the point where the ability to interbreed is lost. We've reproduced this effect several times in history with dogs, parakeets, tropical fish, corn, etc. In some cases, our efforts at selective breeding have made it impossible for our "domesticated" plant or animal to breed with the original parent plant or animal.
It would appear that a ring species is an example of the same principle at work in kind of a stretched out way due to a unique type of geographic isolation.
The real issue here is information. Has information been added to the salamander populations, or has information been removed? "Uphill" evolution, the kind that goes from eukayrote to human being requires the uphill kind. Information must be added. Evolution that produces ring species can work with loss of information.
This may demonstrate how salamanders can split into salamandar species, but does not explain how Dinosaurs, for example, can become birds.
Now, if you supposed that the original life on planet Earth contained all the genetic information for all the species we find on the planet, then evolution can easily explain what we see today.
However, information theory makes a pretty strong argument, mathematically, that evolution cannot add information to a system. The main argument is that information is independent of the storage mechanism, so that damaging the mechanism (mutation in the DNA) always causes loss of information. The mathematical arguments are pretty sound, and the empirical evidence seems to lean that way, too. Specifically, the fact that randomly induced changes in DNA do not produce random mutations in the organism. For example, bombarding fruit flies with radiation creates a PATTERN of mutations, usually some form of multiple limbs or organs, or the loss of limbs or organs. The mutations are not random.
Skin temperature and skin color are unrelated. Why not select for thicker layers of subdermal fat, and an oil secretion to protect the skin? We have fat, oily skinned people in the world, too.
They supplement with fish oils. If I remember correctly, cold-water fish are the kind needed.
Eating livers and kidneys of any animal will do it, too.
Because of this, their skin is not forced to lighten for production of vitamin D. Their skin color is closer to the world-average brown.
Then why don't we see a gradual darkening again as we head north? Brown in the south, brown in the north, white in the middle. That's the predicted pattern.
What's really interesting, is that there really is no need to hang onto this argument in the face of the contradicting evidence. It doesn't disprove evolution, or give creationists an upper hand to admit that we don't know why white people are where they are and brown people are where they are. It's really nothing more, I think, than having the desire to show the evolution can answer every question about living organisms right now. That's why social Darwinism is so big right now, and why every time somebody discovers something, the scramble is to place it in the evolutionary framework as quickly as possible.
(Michael Jackson just signed up as a test subject.)
ROTFL. That's the first thing I thought of too when I read the title!
Social Darwinism is big now?
Maybe you meant evolutionary psychology or the like, but "social darwinism" was a set of ideas that reigned many decades ago and are not at all like what you describe.
But then Social Darwinism was a corruption of Darwin's ideas too.
But what they said was that when races began, it was "one of humanities greatest sources of strife." Yet most African countries today that are 99% black are plagued with strife. Much more so than American cities that are of mixed race.
This is a ridiculous argument. The author didn't say racism is "humanity's only source of strife," just one of the greatest sources. Which is factually correct. You're reading way too much into it if you see anything else there.
I know. That's what I wrote when I quoted the article. But it way overstates the threat of racism. Stalin murdered millions of people of his own race. So did Mao and other communists. Most murders in America are black on black or white on white, not racist.
Albinism is a mutation ... I do not see it mentioned in this article. Is it irrelevant?
Now you're catching on.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.