Interesting article mentioned on eurogenes. "Its main finding is that upper caste Indians are generally lighter skinned than other Indians, particularly those from tribal groups. "Taken together, our findings suggest that the social structure defined by the caste system in India has a profound influence on the skin pigmentation patterns of the subcontinent. In particular, social category and associated SNPs explain about 32% and 6.4%, respectively, of the total phenotypic variance." "