Section : Notes de congrès/conférences

Skin Evolutionary Theories in Early Mankind (Applied Darwinian principles) and the importance of MC1R

  • Characteristics of the skin in the direct predecessor of mankind (homo (neandertalis…)):
    • functional hairlessness
    • increased density of eccrine glands
    • persistence of hair follicular units
  • 1 million years ago, the predecessors of mankind, the skin (in addition to becoming hairless became) darkly pigmented and MC1R became invariant
  • It was been shown that in that skin; High levels of melanocortins were found  in UV irradiated skin
  • The role of MC1R
    • induction of protective pigmentation
    • activation of the DNA damage response
  • So the skin of the direct predecessors of mankind was hairless, darkly pigmented and was the primary interface with the environment
  • What were the selective pressures according to Darwinian principles:
    • increased barrier functions (reduced pH)
    • protection against Ultraviolet radiation
  • Further differentiation into subgroup skin subtypes (caucasian, asian, arabic skin…) was by selective evolution adapted to migration: the skin is the result of a biocultural selective adaptation and is a combination of lightly follicular density, with a more or less pigmented skin responding more or less to UV radiation

Further reading: http://www.globale-dermatologie.com/en/skin-color-regulation-by-genes.html#.VAk3-0jbw4Y

Contributors

Dr Christophe Hsu – dermatologist. Geneva, Switzerland

Source of Information. Jablonski N. Natural Selection  and the Natural Evolution of Skin Color Phenotypes. 2014 (09) – International Pigment Cell Conference (IPCC). Singapore