Manuel Ferrando-Bernal

Light skin facilitates the penetration of ultraviolet light (UV) radiation through the skin, increasing the synthesis of vitamin D that in turn stimulates bone formation. It has been suggested that light skin appeared in the ancestors of modern Europeans as an adaptation to the conditions of low UV radiation in high latitudes; however, paleogenetic studies have recently shown it did not evolve when Upper Palaeolithic human groups first peopled this continent, around 45,000 years ago, but much later, after the development of agriculture, 10,000 years ago. Neolithic Europeans may have struggled with a decrease of bone formation rate and a reduction of the bone mineral density (BMD) associated with the new sedentary lifestyle. Here I suggest that light skin evolved to increase the vitamin D synthesis (a stimulator of the BMD), balancing out the negative effects on the BMD during the Neolithic. According to the idea, I found that SNPs related to BMD may have changed after the European Agricultural Revolution, and possibly in correlation with skin pigmentation associated SNPs.