Variation of Human Hairiness: A Possible Adaptation to Solar Radiation and Melanin

• Authors: Amrita Dhugga , Maciej Henneberg , Jaliya Kumaratilake
• Languages of publication: EN

Abstracts

EN

Many theories have been advanced to explain human hairlessness, however, there is no consensus. This study of 76 males observed that skin reflectance measuring skin colouration and melanin pigmentation correlated with hair size and follicle density. Individuals with a greater concentration of melanin within the superficial layer of the skin had a lower follicle density and smaller sizes of hairs. In contrast, individuals with a lower melanin concentration and lighter skin colour had a full range of hairiness. This leads to the suggestion that over the course of human evolution, high concentrations of melanin in consistently exposed to ultraviolet radiation areas developed first and that hair loss was a consequence of competition in the skin between melanin production and hair growth. Darker pigmented skin and lower follicle density are significantly correlated (R2=0.283; p<0.05). Individuals with darker skin had a mean of 4.91 follicles per cm2 whereas those with lighter skin reflectance had 11.20 follicles per cm2. This suggests that increased concentrations of melanin in the basal layer of the epidermis may limit hairiness by negatively influencing the skin's ability to produce hair.

Keywords

EN

evolution of hair; Von Luschan's Scale; skin colour reflectance; hairiness

• Publisher: Sciendo
• Journal: Anthropological Review
• Year: 2014
• Volume: 77
• Issue: 2
• Pages: 219-232

Dates

received

2014-04-06

accepted

2014-06-15

online

2014-07-15

Contributors

author

Amrita Dhugga

• Biological Anthropology and Comparative Anatomy Unit, The University of Adelaide

author

Maciej Henneberg

• Biological Anthropology and Comparative Anatomy Unit, The University of Adelaide

author

Jaliya Kumaratilake

• Biological Anthropology and Comparative Anatomy Unit, The University of Adelaide

References

• Ali I, Wojnarowska F. 2011. Physiological changes in scalp, facial and body hair after the menopause: a cross-sectional population-based study of subjective changes. Brit J Dermatol 164:508-13.[WoS]
• Becker WS. 1927. Melanin Pigmentation Systematic Study of the Pigment of the Human Skin and Upper Mucous Membranes, with Special Consideration of Pigmented Dendritic Cells. Arch Derm Syphilol 16:259-90.[Crossref]
• Candille SI, Absher DM, Beleza S, Bauchet M, McEvoy B, Garrison NA, Li JZ, Myers RM, Barsh GS, Tang H, Shriver MD. 2012. Genome-Wide Association Studies of Quantitatively Measured Skin, Hair, and Eye Pigmentation in Four European Populations. PLoS ONE 7:1-12.[WoS]
• Chiao FB, Resta-Flarer F, Lesser J, Ng J, Ganz A, Pino-Luey D, Bennett H, Perkins C, Witek B. 2013. Vein visualization: patient characteristic factors and efficacy of a new infrared vein finder technology. Brit J Anaesth 110:966-71.[WoS][Crossref]
• Costin G-E, Hearing VJ. 2007. Human skin pigmentation: melanocytes modulate[PubMed]
• skin color in response to stress. FASEB J 2:976-94.
• Dean I, Siva-Jothy MT. 2012. Human fine body hair enhances ectoparasite detection. Biology Letters 8:358-61.[WoS][PubMed][Crossref]
• Foote S. 2013. An Evolved Hair Growth Mechanism in Mammals, Implications in Human Physiology. Open Science Repository Anthropology. e70081946. doi:10.7392/ Anthropology.70081946.
• Hardy A. 1960. Was man more aquatic in the past. New Scientist 7:5.
• Hochberg Z, Templeton A. 2010. Evolutionary perspective in skin color, vitamin D and its receptor. Hormones 9:307-11.[Crossref]
• Hofreiter M, Schöneberg T. 2010. The genetic and evolutionary basis of colour variation in vertebrates. Cell Mol Life Sci 67:2591603.[WoS]
• Jablonski NG. 2004. The Evolution Of Human Skin And Skin Color. Annu Rev Anthropol 33:585-81.[Crossref]
• Jablonski NG, Chaplin G. 2000. The evolution of human skin coloration. J Hum Evol 39:57-106.[Crossref][PubMed]
• Jody PE, Wickett RR, Raymond EB. 2009.
• Mechanisms Regulating Skin Pigmentation: The Rise and Fall of Complexion Coloration. Int J Mol Sci 10: 4066-87.[WoS][PubMed]
• Lessin SR, Perlis CS, Zook MB. 2012. How Ultraviolet Radiation Tans Skin. In: CJ Heckman, SL Manne, CJ Heckman and SL Manne, editors. Shedding Light on Indoor Tanning. New York, NY US: Springer Science + Business Media. 87-94.
• Lin JY, Fisher DE. 2007. Melanocyte biology and skin pigmentation. Nature 445:84350.[WoS]
• McNeil EM, Ritchie A, Melton DW. 2013.
• The toxicity of nitrofuran compounds on melanoma and neuroblastoma cells is enhanced by Olaparib and ameliorated by melanin pigment. DNA Repair 12:100006.[WoS]
• Montagna W. 1972. The skin of nonhuman primates. American Zoologist 12:109-24.
• Morgan E. 1982. The Aquatic Ape. A theory of human evolution. New York: Stein and Day. 27-34
• Niemitz C. 2010. The evolution of the upright posture and gait - a review and a new synthesis. Naturwissenschaften 97:241-63.[Crossref][WoS]
• O'Keefe JH, Vogel R, Lavie CJ, Cordain L. 2011. Exercise Like a Hunter-Gatherer: A Prescription for Organic Physical Fitness. Prog Cardiovasc Dis 53:471-79.[WoS][Crossref]
• Padilla MA, Veprinsky A. 2012. Correlation Attenuation Due to Measurement Error: A New Approach Using the bootstrap procedure. Educ Psychol Meas 75:827-46.[WoS][Crossref]
• Pagel M, Bodmer W. 2003. A naked ape would have fewer parasites. Proceedings of the Royal Society of London. Series B: Biological Sciences 270(S1):117-19.
• Rantala MJ. 1999. Human nakedness: adaptation against ectoparasites?. Int J Parasitol 29-1987-89.[PubMed]
• Rantala MJ. 2007. Evolution of nakedness in Homo sapiens. Journal of Zoology 273:1-7.[WoS]
• Schwartz, GG & Rosenblum, LA (1981). Al-lometry of primate hair density and the evolution of human hairlessness. Am J[WoS]
• Phys Anthropol 55:9-12.
• Sitek A, Żądzińska E, Rosset I. 2012. Effects of psychological stress on skin and hair pigmentation in Polish adolescents. An-thropol Rev 75:1-17.
• Sitek A, Żądzińska E, Rosset A, Antoszewski B. 2013. Is increased constitutive skin and hair pigmentation an early sign of puberty? HOMO 64(3):205-14.[PubMed][WoS]
• Slominski A, Paus R, Costantino R. 1991. Differential expression and activity of melanogenesis-related proteins during induced hair growth in mice. J Invest Der-matol 96:172-79.
• Sturm RA. 2009. Molecular genetics of human pigmentation diversity. Hum Mol Gen 18:9-17.[Crossref][WoS]
• Toll R, Jacobi U, Richter H, Lademann J, Schaefer H, Blume-Peytavi U. 2004. Penetration profile of microspheres in folli-cular targeting of terminal hair follicles. J Invest Dermatol 123:168-76.
• Valisuo P, Harju T, Alander J. 2011. Reflectance measurement using digital camera and a protecting dome with built in light source. J Biophotonics 4:559-64.[Crossref][WoS][PubMed]
• Van Neste D, Tobin DJ, 2004. Hair cycle and hair pigmentation: dynamic interactions and changes associated with aging. Micron 35:193-200.[Crossref][PubMed]
• Yuen AWC, Jablonski NG. 2010. Vitamin D: In the evolution of human skin colour. Med Hypotheses 74:39-44.[WoS][PubMed][Crossref]

Identifiers

DOI

10.2478/anre-2014-0017