Genetic evidence for the convergent evolution of light skin in Europeans and East Asians.
Human skin pigmentation shows a strong positive correlation with ultraviolet radiation intensity, suggesting that variation in skin color is, at least partially, due to adaptation via natural selection. We investigated the evolution of pigmentation variation by testing for the presence of positive directional selection in 6 pigmentation genes using an empirical F(ST) approach, through an examination of global diversity patterns of these genes in the Centre d'Etude du Polymorphisme Humain (CEPH)-Diversity Panel, and by exploring signatures of selection in data from the International HapMap project. Additionally, we demonstrated a role for MATP in determining normal skin pigmentation variation using admixture mapping methods. Taken together (with the results of previous admixture mapping studies), these results point to the importance of several genes in shaping the pigmentation phenotype and a complex evolutionary history involving strong selection. Polymorphisms in 2 genes, ASIP and OCA2, may play a shared role in shaping light and dark pigmentation across the globe, whereas SLC24A5, MATP, and TYR have a predominant role in the evolution of light skin in Europeans but not in East Asians. These findings support a case for the recent convergent evolution of a lighter pigmentation phenotype in Europeans and East Asians.
Norton
Heather L
HL
Department of Anthropology, The Pennsylvania State University, PA, USA. hnorton@email.arizona.edu
Kittles
Rick A
RA
Parra
Esteban
E
McKeigue
Paul
P
Mao
Xianyun
X
Cheng
Keith
K
Canfield
Victor A
VA
Bradley
Daniel G
DG
McEvoy
Brian
B
Shriver
Mark D
MD
D001741:Black or African American / Q000235:genetics; D054366:Agouti Signaling Protein; D000951:Antigens, Neoplasm / Q000235:genetics; D017920:Antiporters / Q000235:genetics; D044466:Asian People / Q000235:genetics*; D005075:Biological Evolution; D016000:Cluster Analysis; D005787:Gene Frequency; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics; D026901:Membrane Transport Proteins / Q000235:genetics; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D012641:Selection, Genetic; D012880:Skin Pigmentation / Q000235:genetics*; D044465:White People / Q000235:genetics*
D054366:Agouti Signaling Protein; D000951:Antigens, Neoplasm; D017920:Antiporters; D036341:Intercellular Signaling Peptides and Proteins; D026901:Membrane Transport Proteins; C489600:OCA2 protein, human; C506584:SLC24A5 protein, human; C510061:SLC45A2 protein, human