Because it's bullshit, skin colour genes differ by race & region, applying modern alleles to an extinct population is bound to be wrong. It was a dumb PR stunt. They even redacted their statements later on.
https://www.newscientist.com/articl...nned-briton-cheddar-man-find-may-not-be-true/
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But one of the geneticists who performed the research says the conclusion is less certain, and according to others we are not even close to knowing the skin colour of any ancient human."
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But one of the geneticists who performed the research says the conclusion is less certain, and according to others we are not even close to knowing the skin colour of any ancient human."
Who retracted it? Just one of their geneticists?
Cheddar Man being dark skinned isn't an anomaly. Dark skin and blue eyes were very prevalent in pre-agricultural Europe.
Read this:
The Mesolithic La Braña, Loschbour WHGs, the Upper Palaeolithic Villabruna individual, and the Neolithic KO1 individual, which has a genetic makeup of a WHGs [27], had dark skin and blue eyes based on their allelic states at the rs1426654, rs16891982 and rs12913832 SNPs [1,2,16,27]; an observation supported by their high probabilities of blue eye color inferred by Hirisplex in this study. The Upper Paleolithic Bichon from central Europe [15] had likely dark-skin and brown eyes (S1 Table). The dark skin and blue eyes phenotype combination was likely very common among WHGs and it has been inferred for four out of five Mesolithic and Upper Paleolithic individuals in western and central Europe. Moreover, the allelic states at the h-1 defining positions suggest that La Braña, Loschbour and Villabruna carried this haplotype. The haplotype determination was inconclusive for the remaining individuals due to alternative alleles and missing data at informative positions. All individuals from this group were predicted to have a dark hair color, where Loschbour, Villabruna and Bichon probably had black hair, whereas La Braña and KO1 present similar probabilities of having brown or black hair (S1 Table).
Jones ER, Gonzalez-Fortes G, Connell S, Siska V, Eriksson A, Martiniano R, et al. Upper Palaeolithic genomes reveal deep roots of modern Eurasians. Nature communications. 2015;6: 8912. doi:10.1038/ncomms9912
How do you determine skin pigmentation from DNA?
This is the answer:
Eye, hair, and skin color/pigmentation was assessed by screening two sets of pigmentation-associated markers recently validated in present-day human populations [10,12–14]. The probability for certain eye and hair color for each ancient individual was computed using the enhanced version 1.0 Hirisplex Microsoft Excel macro [14], a SNP system originally designed for forensic purposes. We attempted to predict skin pigmentation using the 8plex system described by Hart et al [12], but as previously reported [2,15], the results were inconclusive for ancient samples using this panel. Similar to previous investigations of ancient humans [2,15–17], we provide skin-color predictions based on the genetic variants at the rs16891982 (in the SLC45A2 gene) and rs1426654 (SLC24A5) SNPs. The derived allele at rs1426654 (SLC24A5) has the greatest effect on skin pigmentation among Europeans [18–21]. Moreover, this variant is part of a light skin haplotype termed “C11”, which is defined by a set of 16 SNPs across 78kb within the SLC24A5 gene. In addition to rs1426654, we investigated the nonsynonymous SNP rs16891982 in the SLC45A2 gene, which is a second major-effect pigmentation locus in Europeans [22]. The derived alleles at both rs1426654 and rs16891982 positions are found at extremely high frequencies in present-day European populations (where the former allele is virtually fixed and the latter is ~90%), an observation that has been interpreted as the signature of recent positive selection in Europeans.
Grossman SR, Andersen KG, Shlyakhter I, Tabrizi S, Winnicki S, Yen A, et al. Identifying recent adaptations in large-scale genomic data. Cell. 2013;152: 703–713. doi:10.1016/j.cell.2013.01.035
https://journals.plos.org/plosbiolo...id=info:doi/10.1371/journal.pbio.2003703.s013
