June 15, 2016 at 03:23PM on Facebook

“The introgression of Neanderthal alleles related to hair, skin pigmentation, and immunity appears to have provided non-Africans with adaptive benefits, perhaps because Neanderthals had preadapted to life in Europe for thousands of years before humans left Africa (Abi-Rached et al. 2011; Mendez et al. 2012; Sankararaman et al. 2014; Vernot and Akey 2014; Dannemann et al. 2016). However, these positively selected genes represent a tiny fraction of Neanderthal introgression’s genetic legacy. A larger number of Neanderthal alleles appear to have deleterious fitness effects, with putative links to various diseases as measured by genome-wide association studies (Sankararaman et al. 2014; Simonti et al. 2016).”
Such a fascinating inversion of the assumptions that once underlay scientific racism! Because one corollary of all this is that those modern humans who contain the smallest Neanderthal genetic legacy are the fittest: Africans.

The Genetic Cost of Neanderthal Introgression