Evolution of human skin pigmentation. Genetic factors underlying variability and association with eye and hair color.
- Autores: Saioa López, Isabel Smith Zubiaga, Neskuts Izagirre Arribalzaga, Santos Alonso Alegre
- Localización: Revista española de antropología física, ISSN-e 2253-9921, ISSN 1887-2042, Nº. 33, 2012, págs. 7-19
- Idioma: inglés
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Resumen
In this review we present an updated overview of the main current hypotheses for the evolution of skin color and the genetic factors underlying its variability, as well as a brief remark of the relationship of skin pigmentation with other pigmentary phenotypes, such as eye and hair color.
Pigmentation has also important biomedical implications, for instance as regards skin cancer development. The continuous nature of skin color in humans seems likely to be the result of adaptive evolution; however, it is currently unknown how selection has affected the genetic architecture of pigmentation loci in different populations. Many hypotheses have been proposed to explain this issue: protection from skin cancer and sunburn, protection against folate deficiency, protection against DNA damage and oxidative stress, permeability barrier or sexual selection.
Human pigmentation is presumed to be under the control of an undetermined number of genes, which may act at different stages of melanogenesis. To date, however, only a few genes have been shown to have effects on normal variation in pigmentation; the strongest evidences are found in the melanogenic genes MC1R, ASIP, SLC24A5, MATP, TYR, TYRP1, DCT, OCA2 and KITLG. There are also other non-melanogenic genes with a putative role in skin pigmentation, such as VDR or beta defensins.
