posted
Here we have another paper showing how genes can differiate racial groups.
quote:
Annals of Human Genetics
OnlineEarly Articles
To cite this article: O. Lao, J. M. de Gruijter, K. van Duijn, A. Navarro, M. Kayser Signatures of Positive Selection in Genes Associated with Human Skin Pigmentation as Revealed from Analyses of Single Nucleotide Polymorphisms Annals of Human Genetics (OnlineEarly Articles). doi:10.1111/j.1469-1809.2006.00341.x Prev Article Next Article Original Article Signatures of Positive Selection in Genes Associated with Human Skin Pigmentation as Revealed from Analyses of Single Nucleotide Polymorphisms
* O. Lao1,21Department of Forensic Molecular Biology, Erasmus University Medical Centre Rotterdam, The Netherlands2Departments of Biology, Netherlands Forensic Institute, The Hague, The Netherlands, * J. M. de Gruijter1,21Department of Forensic Molecular Biology, Erasmus University Medical Centre Rotterdam, The Netherlands2Departments of Biology, Netherlands Forensic Institute, The Hague, The Netherlands, * K. van Duijn1,21Department of Forensic Molecular Biology, Erasmus University Medical Centre Rotterdam, The Netherlands2Departments of Biology, Netherlands Forensic Institute, The Hague, The Netherlands, * A. Navarro33Institucio Catalana de Reserca i Estudis Avancats (ICREA), and Unitat de Biologia Evolutiva, Departament de Ciencies de la vida i de la salut, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain and * M. Kayser1*1Department of Forensic Molecular Biology, Erasmus University Medical Centre Rotterdam, The Netherlands*Address for correspondence and reprints: Prof. Dr. Manfred Kayser, Department of Forensic Molecular Biology, Erasmus MC - University Medical Centre Rotterdam, Medical-Genetic Cluster, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands, E-mail: m.kayser@erasmusmc.nl
* 1Department of Forensic Molecular Biology, Erasmus University Medical Centre Rotterdam, The Netherlands 2Departments of Biology, Netherlands Forensic Institute, The Hague, The Netherlands 3Institucio Catalana de Reserca i Estudis Avancats (ICREA), and Unitat de Biologia Evolutiva, Departament de Ciencies de la vida i de la salut, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain
*Address for correspondence and reprints: Prof. Dr. Manfred Kayser, Department of Forensic Molecular Biology, Erasmus MC - University Medical Centre Rotterdam, Medical-Genetic Cluster, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands, E-mail: m.kayser@erasmusmc.nl Summary
Phenotypic variation between human populations in skin pigmentation correlates with latitude at the continental level. A large number of hypotheses involving genetic adaptation have been proposed to explain human variation in skin colour, but only limited genetic evidence for positive selection has been presented. To shed light on the evolutionary genetic history of human variation in skin colour we inspected 118 genes associated with skin pigmentation in the Perlegen dataset, studying single nucleotide polymorphisms (SNPs), and analyzed 55 genes in detail. We identified eight genes that are associated with the melanin pathway (SLC45A2, OCA2, TYRP1, DCT, KITLG, EGFR, DRD2 and PPARD) and presented significant differences in genetic variation between Europeans, Africans and Asians. In six of these genes we detected, by means of the EHH test, variability patterns that are compatible with the hypothesis of local positive selection in Europeans (OCA2, TYRP1 and KITLG) and in Asians (OCA2, DCT, KITLG, EGFR and DRD2), whereas signals were scarce in Africans (DCT, EGFR and DRD2). Furthermore, a statistically significant correlation between genotypic variation in four pigmentation candidate genes and phenotypic variation of skin colour in 51 worldwide human populations was revealed. Overall, our data also suggest that light skin colour is the derived state and is of independent origin in Europeans and Asians, whereas dark skin color seems of unique origin, reflecting the ancestral state in humans.
Here we have another paper showing how genes can differiate racial groups.
Which specific genes define which "races"?
Do you think northwest Europeans are the same 'race' as southern Europeans? What about southern Europeans and southeastern Asians like say, the Japanese?
Understanding genetics and biology is in order; this cannot be overemphasized: There are of course variations in populations, but doesn't equate to "sub-species" level in humans to warrant 'races'. Variations in pigmentation is simply a response to environment, i.e. vitamin D regulation by UV radiation and dietary habits.
Case in point, tell me about a single gene that exclusively produces dark skin gradients?
Meanwhile, for reminders and to reiterate the point about undertanding the genetics:
"**Several independent genes must work in concert to produce the deepest complexion—the extreme of the darkness adaptation.**
Many things can go wrong and, when they do, the result is a lighter complexion. For instance, deleterious mutations at the five loci above result in various forms of albinism, whether the patient’s heritage is dark or pale. In other words, there are many random ways “accidentally” to evolve a light complexion. **But no genetic defect can make the child of light-skinned parents come out dark.** [Nelson’s syndrome does this, but it is due to a pituitary tumor, not to a mutation, nor to genetic variability (Robins 1991, 125-26)]." - Frank Sweet
^From common sense, it is relatively easier to attain loss of pigmentation with nucleotide polymorphisms in pigmentation genes. Hence, light skin in a Japanese or a Southern European, need not invoke gene flow as an explanation.
Posts: 5964 | Registered: Jan 2005
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posted
Good article, Dr. Winters. Of course it completely contradicts your desire to associate skin color with racial classifications.
We know that you don't understand this for two reasons.
1) You really don't understand biology, in fact you seem averse to it, and so it's easy for you to completely misconstrue what bioanthropologists are saying.
2) You are primarily and by your own admission, and ideologue. So when you encounter information that refutes your ideological bias - you simply distort it and pretend that it says something that supports you.
So, we'll ignore your commentary and deal directly with what this very good study is *actually saying*.
quote:The data also suggest that light skin colour is the derived state and is of independent origin in Europeans and Asians
Meaning Europeans and North Asians developed lighter skin distinctly *from EACH OTHER*.
Therefore light skin per se does not denote a recent common ancestry. Therefore it cannot denote a race.
quote:whereas dark skin color seems of unique origin, reflecting the ancestral state in humans.
Meaning, all ancestors of all humans, were originally black, regardless of whether they are now, or not.
This means that modern whites are just as much descendant of ancient blacks as modern blacks are.
It also means that modern blacks are not necessarily any more related to ancient blacks or each other, than they are to non blacks.
Blacks of India and Asia are much more closely related to non Blacks of the same region than they are to Blacks of Africa.
Blacks of Africa are in some cases more closely related to non blacks of Africa, Europe and SouthWest Asia than they are to blacks in SouthEast Asia, the Pacific Island and Australia.
Therfore dark skin does not denote a race.
All modern biologists agree on this fact.
The study cited in the parent post agrees on this fact.
The only one who disputes it is Dr. Winters..
But Dr. Winters disputes via -> 'obtuseness'.
Argument by obtuseness occurs when you pretend to not understand something, no matter how often or how clearly it is explained.
But it is a flawed approach to debate.
It makes the practictioner appear to be ill-educated and primarily seeking to convince the even worse educated.
All the while, it provides and opportunity for the well informed to teach, not Winters of course, but, everyone else who is actually predisposed to learning. Posts: 15202 | Registered: Jun 2004
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quote:Originally posted by Supercar: Which specific genes define which "races"?
Dr Winters is left to fabricate and answer since the skin color article in question says nothing about races whatsoever.
But here is a skin color study that does:
Pigmentation genes are unlike the bulk of the genetic variation among populations and can, and should, be used to help educate the general public about the distribution of genetic variation across the populations of the world and the lack of meaning of 'race' as a system of biological classification.
These findings support a case for the *recent* *convergent* evolution of a lighter pigmentation phenotype in Europeans and East Asians.
If one were arguing via obtuseness then I suppose Kittle's point would need to be spelt out....
convergent evolutionThe process whereby two -unrelated- structures in -unrelated- organisms evolve to perform similar functions.Posts: 15202 | Registered: Jun 2004
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posted
It astounds me how someone ten times smarter than me like Winters can actually believe something like that.
Then again, the mere fact that he has to "fabricate" just to make these articles correlate with his dagma would suggest that he knows it's un-true.
Either that or his mental state is so bad to where he believes he has super-powers to where he can make things true simply by imagining them.
That reality relies on his every thought and that he alone can do whatever he wants, and this forum is a figment of his imagination. Oops, that's enough out of me for today!! !
quote: Dr Winters is left to fabricate and answer since the skin color article in question says nothing about races whatsoever.
Here is the evidence.
quote:
To shed light on the evolutionary genetic history of human variation in skin colour we inspected 118 genes associated with skin pigmentation in the Perlegen dataset, studying single nucleotide polymorphisms (SNPs), and analyzed 55 genes in detail. We identified eight genes that are associated with the melanin pathway (SLC45A2, OCA2, TYRP1, DCT, KITLG, EGFR, DRD2 and PPARD) and presented significant differences in genetic variation between Europeans, Africans and Asians. In six of these genes we detected, by means of the EHH test, variability patterns that are compatible with the hypothesis of local positive selection in Europeans (OCA2, TYRP1 and KITLG) and in Asians (OCA2, DCT, KITLG, EGFR and DRD2), whereas signals were scarce in Africans (DCT, EGFR and DRD2).
Need I say more.
-------------------- C. A. Winters Posts: 13012 | From: Chicago | Registered: Jan 2006
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posted
^ Good move, Dr. Winters. Stay silent, and listen...
quote: Pigmentation genes can, and should, be used to help educate the general public about the distribution of genetic variation across the populations of the world and the lack of meaning of 'race' as a system of biological classification.
quote: Dr Winters is left to fabricate and answer since the skin color article in question says nothing about races whatsoever.
quote:Here is the evidence.
To shed light on the evolutionary genetic history of human variation in skin colour we inspected 118 genes associated with skin pigmentation in the Perlegen dataset, studying single nucleotide polymorphisms (SNPs), and analyzed 55 genes in detail. We identified eight genes that are associated with the melanin pathway (SLC45A2, OCA2, TYRP1, DCT, KITLG, EGFR, DRD2 and PPARD) and presented significant differences in genetic variation between Europeans, Africans and Asians. In six of these genes we detected, by means of the EHH test, variability patterns that are compatible with the hypothesis of local positive selection in Europeans (OCA2, TYRP1 and KITLG) and in Asians (OCA2, DCT, KITLG, EGFR and DRD2), whereas signals were scarce in Africans (DCT, EGFR and DRD2).
Need I say more.
Please do say more, in terms of how this specifically supports the idea of "races".
Posts: 5964 | Registered: Jan 2005
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If you want to ask questions on genetics, then why don't you ask in stead of to present the opponents' view?
Posts: 2198 | Registered: Jun 2006
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If you want to ask questions on genetics, then why don't you ask in stead of to present the opponents' view?
To keep people aware of the fact that scientists continue to believe in race as a physical reality.
I wish we lived in a color blind world but we don't. Therefore you should not let people go asleep and place themselves in japarady. The Jews thought everything was alright in Germany when the Nazis came to power, and we see what happen to them--six (6) million people killed.
Many of the people on this forum come from Africa. People from Africa do not understand that the Europeans can be ready to commit genocide at anytime, even if they had been friendly with the vitims earlier, e.g., Germany and Bosnia.
.
-------------------- C. A. Winters Posts: 13012 | From: Chicago | Registered: Jan 2006
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quote:Clyde Winters: Many of the people on this forum come from Africa. People from Africa do not understand that the Europeans can be ready to commit genocide at anytime, even if they had been friendly with the vitims earlier, e.g., Germany and Bosnia.
So what you're proposing is to arm ourselves and be ready for a race war?
Posts: 1420 | Registered: May 2005
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quote: People from Africa do not understand that the Europeans can be ready to commit genocide at anytime, even if they had been friendly with the vitims earlier, e.g., Germany and Bosnia.
^ logical fallacy non-sequitur, appeal to prejudice, well-poisoning, histrionic language...etc..
Not to mention the curiously smug "People from Africa do not understand ......".
Winters thinks he knows bettter than "people from Africa"?
I told you, the less said the better.
Too bad you won't listen.
Posts: 15202 | Registered: Jun 2004
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quote: -------------------------------------------------------------------------------- Clyde Winters: Many of the people on this forum come from Africa. People from Africa do not understand that the Europeans can be ready to commit genocide at anytime, even if they had been friendly with the vitims earlier, e.g., Germany and Bosnia.
So what you're proposing is to arm ourselves and be ready for a race war?
No. I am saying that you must be aware of the racism that exist in society so that you don't become a victim.
When I was growing up in Chicago in the 1960's, Blacks knew they should not be waiting on Cicero for a bus after dark on by themselves. We knew that if we did, there was a good chance you might get murdered or beat up by racists whites. As a result, Blacks tried to avoid this street unless they were going to work.
Recently, a Nigerian family's home was bombed in a Chicago suburb. They were shocked.
I wasn't, most Afro-Americans know not to be the only Black in a predominately white neighborhood , since you may be hurt by racist whites. This Nigerian family was shocked because they felt it was alright to live anywhere they chose to live .
Afro-Americans know that racism exist. They know that there are certain places we should avoid for our personal safety. The Africans who had their home fire bombed was surprised because they felt European-Americans only held racist ideas about Afro-Americans, they learned the hard way when whites are angrey they will attack any member of the other population, they see as an enemy.
Due to this reality, it's important that all people remember that racism exist both as a scientific and social phenomenon so they will not be a victim. You don't have to strap up (i.e., get a gun) to protect yourself from violence because you are out numbered and armed resistence would be futile. Yet it is good to know that racism exist so you can protect yourself from personal violence from the minority of whites who want to murder Blacks, just because they are Black.
posted
Gene That Determines Skin Color Is Discovered, Scientists Report
By NICHOLAS WADE
A gene that is responsible for the pale skin of Europeans and the dark skin of Africans has been discovered by scientists at Pennsylvania State University.
The gene comes in two versions, one of which is found in 99 percent of Europeans and the other in 93 to 100 percent of Africans, the researchers report in today's issue of Science.
The gene is unusual because with most human genes, different versions are generally shared, though one version may be more common in one race than another. One exception is the Duffy null allele, a version of a gene that prevents malaria, that is found almost exclusively in one race, sub-Saharan Africans.
The new gene falls into the same category as the Duffy gene, and it may shed light on the evolutionary pressures to which Europeans were subjected as their ancestors, who were presumably dark skinned, moved into the northern latitudes some 40,000 years ago.
Humans acquired dark skins in Africa about 1.5 million years ago to shield their newly hairless bodies from the sun. Its ultra-violet rays destroy folic acid, a shortage of which leads to birth defects.
But when the modern humans who left Africa began to live in northern latitudes, they needed more sunlight to penetrate the skin, to permit the chemical reaction that produces vitamin D.
The new gene was first identified not in humans but in a mutant zebra fish, a small striped fish common in aquariums. The mutant fish are known as golden, because their stripes, usually black, are much paler and their bodies more yellow.
Dr. Keith C. Cheng, an author of the report, and his colleagues showed that the golden version of the fish gene altered production of melanosomes, the tiny black particles of pigments that give skin its color.
The researchers then found that in humans, who have their own form of the gene, the version common in Africans allowed larger melanosomes, which tend to clump together, whereas the version in Europeans produced smaller and more dispersed melanosomes.
Asians have the same version of the gene as Africans, so they presumably acquired their light skin through the action of some other gene that affects skin color, said Dr. Cheng.
Mark D. Shriver, another author of the article, said his laboratory was trying to assess when the European version of the gene became so common, as well its geographical origin.
The intense selective pressure that drove the version to become universal in Europeans may have included sexual selection.
"In Africa people are much darker than they need to be for UV protection, so to me that screams sexual selection," Dr. Shriver said. Black skin, in other words, may have been favored by men and women in sexual partners, just as pale skin may have been preferred in sexual partners among Europeans and Asians.
Posts: 83 | From: Quebec, Canada | Registered: Feb 2006
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quote:Humans acquired dark skins in Africa about 1.5 million years ago
Yes, again - common ancestry and skin color of all people - black is not a race.
quote:But when the modern humans who left Africa began to live in northern latitudes, they needed more sunlight to penetrate the skin, to permit the chemical reaction that produces vitamin D.
Adaptation to environment.
quote:Asians have the same version of the gene as Africans, so they presumably acquired their light skin through the action of some other gene that affects skin color, said Dr. Cheng.
Convergent evolution.
quote:The intense selective pressure that drove the version to become universal in Europeans may have included sexual selection.
"In Africa people are much darker than they need to be for UV protection, so to me that screams sexual selection," Dr. Shriver said.
Possible, but the best cases for sexual selection are those wherin the resultant phenotype would be selected against by purely environmental processess.....darker skins in northern climes and lighter skins in tropical climes make the best cases for sexual selection.
The article referenced has actually been posted prior and communicates the same knowledge that we have been sharing on this forum for at least a year now.
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"In Africa people are much darker than they need to be for UV protection, so to me that screams sexual selection," Dr. Shriver said. Black skin, in other words, may have been favored by men and women in sexual partners, just as pale skin may have been preferred in sexual partners among Europeans and Asians.
Dr. Shiver's assessment to me seems questionable. For one, Africans don't come in uniform shades of skin color. Some are darker than others. Some of the darkest groups amongst Africans expectedly reside near the equatorial regions. Sexual selection usually involves one sex to be adapted in a certain way, while the corresponding sex usually isn't. Hence sexual selection, as Frank Sweet put it:
An alternative explanation is that the extraordinary paleness of Europeans was due to sexual selection—it was more attractive to the opposite sex (Cavalli-Sforza, Menozzi, and Piazza 1994, 145).
The problem with this speculation is that sexual selection normally results in a trait’s strong sexual dimorphism.
Vitamin D regulation and corresponding melanin production has reasonably been accounted for by the effects of the interplay of UV radiation and diet.
Posts: 5964 | Registered: Jan 2005
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No. I am saying that you must be aware of the racism that exist in society so that you don't become a victim.
When I was growing up in Chicago in the 1960's, Blacks knew they should not be waiting on Cicero for a bus after dark on by themselves. We knew that if we did, there was a good chance you might get murdered or beat up by racists whites. As a result, Blacks tried to avoid this street unless they were going to work.
Recently, a Nigerian family's home was bombed in a Chicago suburb. They were shocked.
I wasn't, most Afro-Americans know not to be the only Black in a predominately white neighborhood , since you may be hurt by racist whites. This Nigerian family was shocked because they felt it was alright to live anywhere they chose to live .
Afro-Americans know that racism exist. They know that there are certain places we should avoid for our personal safety. The Africans who had their home fire bombed was surprised because they felt European-Americans only held racist ideas about Afro-Americans, they learned the hard way when whites are angrey they will attack any member of the other population, they see as an enemy.
Due to this reality, it's important that all people remember that racism exist both as a scientific and social phenomenon so they will not be a victim. You don't have to strap up (i.e., get a gun) to protect yourself from violence because you are out numbered and armed resistence would be futile. Yet it is good to know that racism exist so you can protect yourself from personal violence from the minority of whites who want to murder Blacks, just because they are Black.
The problem with you is that, you seem to think people aren't aware of social construct of 'human races'. You confuse social constructs with biological reality. If somebody thought that they were biologically superior to you, then you'd buy it? Would you consider this to be a social perception, or a biological reality?
-------------------- Truth - a liar penetrating device! Posts: 5964 | Registered: Jan 2005
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posted
quote: "In Africa people are much darker than they need to be for UV protection, so to me that screams sexual selection," Dr. Shriver said. Black skin, in other words, may have been favored by men and women in sexual partners, just as pale skin may have been preferred in sexual partners among Europeans and Asians. --------------------------------------------------------------------------------
The comment is an absurd one to begin with since people are as they are based on their obvious environmental and genetic makeup. Dr Shriver is going beyond biology and "showing social fabrication" since people prefer those in proximity to them who share the same cultural imperatives, regardless of ethnicity. Dr Shriver's madness again makes a sweeping statement implying that Asians and Europeans share the same corpus of supposed values regarding the love of pale skin, when in fact this only pertained to a small segment of Asians!
The overcategorization of Asians as a homogenous group is humorous so stuff like this damages research despite the data showing what it shows!
Posts: 1290 | From: usa | Registered: May 2005
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I hear you. But we ought to be aware and awake, and not necessarily paranoid, feel me? There will always be evil men in this world. Honestly, if the Black Man was running this world, there would be just as much corruption. Throughout human history, wickedness begins to prevail, and societies deteriorate. Hence, we mush be aware and alert, but we mush reject any type of paranoia, feel me? Salaam
Posts: 826 | From: U.S.A. | Registered: Jun 2006
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quote:Khadija: "In Africa people are much darker than they need to be ...."
much darker than they need to be??? OMG
Well, it says.. "In Africa people are much darker than they need to be [(for protection against UV radiation)]...."Posts: 5555 | From: Tha 5th Dimension. | Registered: Apr 2006
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quote:Khadija: "In Africa people are much darker than they need to be ...."
much darker than they need to be??? OMG
Well, it says.. "In Africa people are much darker than they need to be [(for protection against UV radiation)]...."
I read the quote! I understand the quote! But to say that someone is darker than they need to be, (for what ever reason) Who is to say someone is darker than they need to be?
Posts: 478 | From: USA | Registered: Feb 2006
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posted
^ I agree that the comment is merely ad hoc opinion and so otherwise pretty much worthless.
Here's a thought then:
Perhaps we should disregard it, and concenetrate on the more substantial, and better substantiated information?
Sometimes and inflamatory comment functions tactically as a form of distraction. This works when the distracting remark is the only thing anyone comments on.
Posts: 15202 | Registered: Jun 2004
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But to say that someone is darker than they need to be, (for what ever reason) Who is to say someone is darker than they need to be?
Might as well be like saying that pale Europeans are 'lighter than they need to be'.
Exactly, and i give the same argument, who is to say? I agree it is ad hoc, nevertheless, the comment made me think about who would be in the position to make a judgement call like this, and then have it transend from opinion to almost fact that is now used as a standard measure across the world. Not to mention the connotation that is assoicated with it.
Posts: 478 | From: USA | Registered: Feb 2006
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