1. Where does Tishkoff and the rest state that? I read many of Tishkoff studies and she never concluded that Pale skin, blond hair and blue eyes are of African origins. Can we please stop this now?
2. Did you not read my study on blue eyes which was a recent study? Again they state the MUTATION happened RECENTLY and way after the out of Africa. Let me post this again:
3. Again if a mutation happened its no longer African. How many times do have to tell you this!????? Can we just end this?
"Variation in human skin and eye color is substantial and especially apparent in admixed populations,
yet the underlying genetic architecture is poorly understood because most genome-wide studies are based on individuals of European ancestry.( Why would Shriver say that if he agreed?) We study pigmentary variation in 699 individuals from Cape Verde, where extensive West African/European admixture has given rise to a broad range in trait values and genomic ancestry proportions.
We develop and apply a new approach for measuring eye color,( New method ) and
identify two major loci (HERC2[OCA2] P = 2.3610262, SLC24A5 P = 9.661029) that account for both blue versus brown eye color and varying intensities of brown eye color. We identify four major loci (SLC24A5 P = 5.4610227, TYR P = 1.161029, APBA2[OCA2] P = 1.561028, SLC45A2 P=661029) for skin color that together account for 35% of the total variance,( 4 for skin 2 for eyes) but the genetic component with the largest effect (,44%) is average genomic ancestry. Our results suggest that adjacent cis-acting regulatory loci for OCA2 explain the relationship between skin and eye color, and point to an underlying genetic architecture in which several genes of moderate effect act together with many genes of small effect to explain ,70% of the estimated heritability.."
Blond or red hair color is very rare in Cape Verde, but there is a wide spectrum of variation in both eye and skin color, and
individuals with dark skin and blue eyes are not infrequent( THEY ARE THERE where did it come from?)
The strong effect of genomic ancestry on skin color is also striking in the context of eye color; there is only a weak correlation between skin and eye color in Cape Verdeans (R‘2 =0.14), and African genomic ancestry is also weakly correlated (R‘2 = 0.08) with eye color (Figure 1c, 1d). Overall, these observations point to different genetic architectures for skin and eye color. ( WEAK Correlation between the skin color and eye color they are not one in the same)
The association of HERC2 and SLC24A5 with eye color is also apparent in individuals who do not have blue or green eyes: ( PEOPLE who have brown eyes still carry the SO CALLED UNIQNE gene for BLUE eyes. ) In the subset of 592 Cape Verdeans whose T-index .0.15 (Figure 1, Figure 2), both loci remain highly significant (HERC2 rs12913832, P = 5.23610216; and SLC24A5 rs2470102, P = 1.12610210), indicating that variation at these loci affects different shades of brown eye color.
Notably absent from the four skin color loci detected in this study are ASIP and KITLG, reported previously to affect skin color in populations with African-European admixture [12,15], and IRF4, MC1R, SLC24A4, TYRP1, reported previously to affect skin color in populations of European ancestry [4,6].( They are do not have the admixture of AF/EUR populations , Why does population have blue eyes if blue eyes came out outside of Africa from EUROPE recently where are these blue eyes coming from? Wouldn't they have ASIP/KITLG like the supposed BLUE-EYED FOREFATHERS? )
The four skin color loci we identified by association analysis act in an ADDITIVE fashion( more you have, the lighter) we found no evidence of dominance at any of the loci, nor evidence of opposite-sign epistasis between loci. For eye color, the ancestral HERC2 (OCA2) allele is mostly dominant over the derived allele, consistent with the near recessive mode of inheritance of blue eye phenotype in Europeans (Figure S3). By contrast, the effects of SLC24A5 on eye color are semi-dominant, and no interaction was found between this gene and HERC2. ( eyes color behaves different than skin and saying there is no "white" gene for skin color)
To explore these ideas, we first examined worldwide allele frequency distributions for the most strongly associated SNP at each locus,
using information from the Human Genome Diversity Project (HGDP) [39] and HapMap III [19].( just testing europeans)
Previous genome-wide studies of human skin and eye color have focused on populations of European ancestry and have been based primarily on categorical and subjective assessment of pigmentary phenotype [4–7].( He thinks they are biased not enough studies on people other than Europeans, how can you say it comes from(XYZ) and only test one group of people )
The abstract from the study and article you posted.
Blue eye color in humans may be caused by a perfectly associated founder mutation in a regulatory element located within theHERC2 gene inhibiting OCA2 expression.
The human eye color is a quantitative trait displaying multifactorial inheritance. Several studies have shown that the
OCA2 locus is the major contributor to the human eye color variation. By linkage analysis of a
large Danish family,(European Family, we finemapped the blue eye color locus to a 166
Kbp region within the
HERC2 gene. By association analyses, we identified two
SNPs within this region that were perfectly associated with the blue and brown eye colors: rs12913832 and rs1129038. Of these, rs12913832 is located 21.152 bp upstream from the
OCA2 promoter in a highly conserved sequence in intron 86 of
HERC2. The brown eye color allele of rs12913832 is highly conserved throughout a number of species. As shown by a Luciferase assays in cell cultures, the element significantly reduces the activity of the
OCA2 promoter and electrophoretic mobility shift assays demonstrate that the two alleles bind different subsets of nuclear extracts. One single haplotype, represented by six polymorphic
SNPs covering half of the 3′ end of the
HERC2 gene, was found in 155 blue-eyed individuals from
Denmark, and in 5 and 2 blue-eyed individuals from
Turkey and Jordan, respectively. Hence, our data suggest a common founder mutation in an
OCA2 inhibiting regulatory element as the cause of blue eye color in humans. In addition, an LOD score of
Z = 4.21 between hair color and D14S72 was obtained in the large family, indicating that
RABGGTA is a candidate gene for hair color.(
only tested Europeans)
Critique of the above study.
'Blue-eyed Humans' do not 'Have A Single, Common Ancestor;
ScienceDaily has a most-retarded title up for a report on some new research,
Blue-eyed Humans Have A Single, Common Ancestor. I already
blogged the paper at
my other blog. The paper roughly
longesthaplotype blocks of any appreciable frequency in the European genome, suggesting massive selection within the last 10,000 years.
We need to be careful about confounding conventional genealogical and demographic descriptions with evolutionary genetic dynamics driven by selection. (can't say blue eyes came from this place just because it was selected there)The history of genes is not always the history of peoples, or, you’re ancestors. Here a Dawkinsian distinction between replicators and vehicles is probably useful.
I know it is a pedantic point, but this sort of sloppiness makes it harder to communicate at the the intersection of genetics and other fields. Genes subject to powerful selection within the last 10,000 years, such as
LCT, often sweep through
segregation,
independent assortment and
recombination a particular
allele will
bleed out of its ancestral genetic background proportional to the power of selection. In other words, the genetic sweep can outrun the demographic wave of advance. That’s why Indians from Uttar Pradesh and Swedes both carry the same variant of
LCT which is probably derived from the Volga region of Russia and do not look similar at all, while Arabs carry a different variant. Despite the phylogeny of
LCT, where Arabs are the outgroup, across most genes Indians are the outgroup.
Over evolutionary time scales phenetic similarity does not necessarily entail genetic similarity, and, genetic similarity does not necessarily entail phenetic similarity.
Addendum: I do acknowledge that it is correct that the vast majority of of people who exhibit blue-eyes do share a common ancestor within the last 10,000 years.(
DOES Not say all people ) But I think emphasizing this point obscures
the genetic facts which underly this assertion. Genomic history and genealogy are obviously related, but they are not coterminous. I think with this story it is important to get across to the typical person that one allele subject to positive selection swept through populations and increased in frequency. Alluding to the fact that the original copy was in one individual seems a trivial point; it is much more noteworthy when the same trait is underpinned by genes not identical by descent, because that defies out expectations.
They're not agreeing with your theory that Africans always carried the pale skin, blonde hair and blue eyes genes. They don't even hint it. Yes the only thing that supports your argument is that they say European hair/eye is not due to environment. Neither I or anyone else on this thread concluded that it was due to that. Again nowhere does it state these genes evolved in Africa. But yet they do agree that pale is was due to environment (vitamin D) was a main factor in pale skin in Europe. Killing your claim that it was not solely due to environment... If environment doesn't play an effect on phenotype, then Africa wouldn't have the highest diversity of phenotypes in the world. And why don't you read what you post?
