Skin colour is one of the most obvious and most variable traits humans possess. As visual creatures, people readily observe these differences in one another. Anthropologist, Dr. Nina Jablonski, and colleague George Chaplin have unraveled the mystery behind the diversity of this distinguishing characteristic in their article, ‘Human skin pigmentation as an adaptation to UV radiation’. The pair have presented the first complete theory of skin colour as an evolutionary adaptation.
Paeleotologists have long known that human ancestors once had bodies covered with dense hair. Several theories on the evolution of the present ‘hairless condition’ exist. In this case, the authors suggest this was in response to hot conditions and the need to lose body heat upon physical activity. As naked beings, their once-protected skin became exposed to a multitude of environmental elements, including abrasion, infection, various chemicals and weather conditions. At the same time as the disappearance of the majority of body hair, humans evolved skin that was a more resilient barrier to such hazards and also contained the protective pigment eumelanin (melanin).
May is Skin Cancer Awareness Month in the US, and it’s likely that the associated awareness campaign has come not a moment too soon. A recent study confirmed that non-melanoma skin cancer has reached epidemic levels in the US, with an estimated 300 percent increase in the number of skin cancers over the past decade and a half.
