Humans evolved ability to tan ‘to cope with changes in amount of sunlight’

By Daily Mail Reporter
Last updated at 5:22 PM on 22nd June 2010

Humans developed the ability to tan to cope with changes in the amount of UV radiation their bodies received during the year, scientists believe.

Researchers from Penn State University in the US studied the way the sun illuminates different parts of the Earth.  

They found that the amount of ultraviolet B light  – which produces vitamin D in human skin – was extremely variable further north due to atmospheric scattering of the light and absorption by oxygen.

The researchers believe that humans began to tan as a way of combatting the huge variations in the amount of ultraviolet light our skins were receiving throughout the year.
Read more: http://www.dailymail.co.uk/sciencetech/article-1288569/Humans-evolved-ability-tan-cope-changes-sunlight.html?ITO=1490#ixzz0sF9Lu9Jc