Category Archives: Skin color

Something else

Posted on August 17, 2015 by gcochran9

Razib has talked about this – here’s what I think. The various sweeping alleles that have made Europeans and North Asians have light skin  were not favored because they helped you garner extra vitamin D, at least not mostly. This … Continue reading →

Posted in Genetics, Skin color | 101 Comments

Faster than Fisher

Posted on November 22, 2014 by gcochran9

There’s a simple model of the spread of an advantageous allele:  You take σ, the typical  distance people move in one generation, and s,  the selective advantage: the advantageous allele spreads as a nonlinear wave at speed  σ * √(2s).  … Continue reading →

Posted in Denisovans, Dietary adaptations, European Prehistory, Evolutionary Medicine, Genetics, Indo-European, Linguistics, Neanderthals, Skin color | Tagged | 77 Comments

Shades of Pale

Posted on January 27, 2014 by gcochran9

If there was an advantage to just being paler –  say because of increased vitamin D production – then any mutation that moderately reduced function of a gene in the melanin pathway would be favored, as long as the change … Continue reading →

Posted in Genetics, Skin color | 138 Comments

Korak

Posted on January 25, 2014 by gcochran9

If the common mutation of SLC24A5 confers an advantage other than increased vitamin-D production, evidence might show up in a mixed ethnic group, formed from one population with a high incidence of the interesting SLC24A5 variant and another with little … Continue reading →

Posted in Genetics, Skin color | 51 Comments

Tar-Zan*

Posted on January 22, 2014 by gcochran9

*(means white skin, like you didn’t know that) A mutant version of SLC24a5 is the biggest single cause of light skin color in Western Eurasia. It’s very widespread: The usual explanation is that light skin ( in Western Eurasia), caused … Continue reading →

Posted in Genetics, Skin color | 62 Comments