Sexual selection as a cause of human skin colour variation: Darwin's hypothesis revisited

  title={Sexual selection as a cause of human skin colour variation: Darwin's hypothesis revisited},
  author={Kenichi Aoki},
  journal={Annals of Human Biology},
  pages={589 - 608}
  • K. Aoki
  • Published 1 January 2002
  • Biology
  • Annals of Human Biology
The dark skin of tropical peoples is likely to be an adaptation to the strong ultraviolet (UV) radiation near the equator, perhaps protecting against sunburn or degradation of folate. By contrast, the adaptive value of light skin is questionable. In particular, the relevance of vitamin D deficiency rickets as a selective factor has been cogently criticized. Population genetic studies on the melanocortin 1 receptor (MC1R) gene (one of the genes responsible for normal human skin colour variation… 

Evolution of Skin Pigmentation Differences in Humans

Human skin pigmentation is a complex trait that evolved as an adaptation to local environmental conditions and several hypotheses that assign a key role to natural selection have been proposed to explain the global distribution of human skin colour.

Human skin-color sexual dimorphism: a test of the sexual selection hypothesis.

  • P. Frost
  • Psychology
    American journal of physical anthropology
  • 2007
Skin color is less sexually dimorphic at some ages, particularly childhood (when it is absent) and adolescence ( when it is still emerging), and most studies are poorly controlled for age, which is a problem for any meta-analysis because relatively few skin reflectance studies exclude adults over 40 years of age.

Genetic evidence for the convergent evolution of light skin in Europeans and East Asians.

A case for the recent convergent evolution of a lighter pigmentation phenotype in Europeans and East Asians is supported by the testing for the presence of positive directional selection in 6 pigmentation genes using an empirical F(ST) approach and a role for MATP in determining normal skin pigmentation variation using admixture mapping methods.

Human skin-color sexual dimorphism: a test of the sexual selection hypothesis.

Testing the prediction that sexual dimorphism should increase with increasing latitude, using adult-only data sets derived from measurements with standard reflectance spectrophotometric devices found no evidence in support of the sexual selection hypothesis.

The genetic architecture of normal variation in human pigmentation: an evolutionary perspective and model.

A tentative three-population model (West Africa, East Asia and North Europe) of the evolutionary-genetic architecture of human pigmentation is provided and a complex evolutionary history is suggested, with selection acting on different gene targets at different times and places in the human past.

Was skin cancer a selective force for black pigmentation in early hominin evolution?

  • M. Greaves
  • Biology
    Proceedings of the Royal Society B: Biological Sciences
  • 2014
Data on age-associated cancer incidence and lethality in albinos living at low latitudes in both Africa and Central America support the contention that skin cancer could have provided a potent selective force for the emergence of black skin in early hominins.

A scan for signatures of positive selection in candidate loci for skin pigmentation in humans.

Results indicate that both light and dark skin may possess adaptive value and photoprotection against sun-induced skin damage/cancer might be proposed as a mechanism that has driven the evolution of human skin pigmentation.

Evolution of human skin pigmentation. Genetic factors underlying variability and association with eye and hair color.

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

The evolution of human skin pigmentation involved the interactions of genetic, environmental, and cultural variables

The primary biological role of human skin pigmentation is as a mediator of penetration of ultraviolet radiation (UVR) into the deep layers of skin and the cutaneous circulation, which represents the baseline condition for modern humans.

Adaptation and co‐adaptation of skin pigmentation and vitamin D genes in native Americans

It is argued that a gene network approach provides tools to explain human skin color variation since it indicates potential alleles co‐evolving in a compensatory way, and since food is also a source of vitamin D, dietary habits should also be considered.



The evolution of human skin coloration.

The highest correlation between skin reflectance and UV levels was observed at 545 nm, suggesting that the main role of melanin pigmentation in humans is regulation of the effects of UV radiation on the contents of cutaneous blood vessels located in the dermis.

Quantitative genetics of human skin color

Skin color has long been of interest to human geneticists and often used as an example of a human quantitative trait under relatively wellunderstood genetic control, but the evolutionary significance and mode of inheritance are still being debated.

Skin color and nutrient photolysis: an evolutionary hypothesis.

Prevention of ultraviolet photolysis of folate and other light sensitive nutrients by dark skin may be sufficient explanation for the maintenance of this characteristic in human groups indigenous to regions of intense solar radiation.

Human pigmentation genetics: the difference is only skin deep

  • R. SturmN. BoxM. Ramsay
  • Biology
    BioEssays : news and reviews in molecular, cellular and developmental biology
  • 1998
Three classes of genes have been examined for their contribution to normal human color variation through the production of hypopigmented phenotypes or by genetic association with skin type and hair color.

Skin-Pigment Regulation of Vitamin-D Biosynthesis in Man

The known correlation between the color of human skin and latitude (Fig. 2) is explainable in terms of two opposing positive adaptations to solar ultraviolet radiation, weak in northern latitudes in

Studies on the inheritance of human skin colour

The present analysk is based upon a population studied in Liverpool during the past 10 years, in which it is often possible to trace the relationship of individuals back to the original miscegenation.

Evidence for variable selective pressures at MC1R.

It is concluded that MC1R is under strong functional constraint in Africa, where any diversion from eumelanin production (black pigmentation) appears to be evolutionarily deleterious.


  • M. Kirkpatrick
  • Biology, Psychology
    Evolution; international journal of organic evolution
  • 1982
The primary conclusion of the present paper is that the initial selective advantages for the female preference assumed by Fisher, O'Donald, and many later authors are not necessary for either the origin or subsequent elaboration of mating preferences for traits associated with reduced survivorship.


Abstract The evolution of a quantitative genetic trait under stabilizing viability selection and sexual selection is modeled for a polygynous species in which female mating preferences are acquired

Variants of the melanocyte–stimulating hormone receptor gene are associated with red hair and fair skin in humans

The findings suggest that in humans, as in other mammals, the MC1R is a control point in the regulation of pigmentation phenotype and, more importantly, that variations in this protein are associated with a poor tanning response.