she talked about the evolution of skin. anthropologist. opened with a discussion about darwin and his writings. there was only one note on the evolution of man in his first writings. but his did talk about the colour of skin. she went on to talk about the NASA satellite data on UV radiation. it is interesting to note that all humans began in the UV intense areas. UVA, UVB and UVC all hit the earth. UVC is precluded by the Ozone layer. UVB is important for bone development. Melanin protected us against UV damage and has probably been in the earth for billions of years. it was a natural sunscreen for the protection of DNA and folate.

then we moved north. All of the UVA still gets thru, but no UVB gets thru. this is interesting because UVA does not have the potential to make vitamin D. thus, the northerners lost their pigmentation. lightly pigmented skin evolved three times.

these movements between our inherently natural environment and our intentional has had tremendous health and social consequence.

it was a good talk. but not great

http://www.anthro.psu.edu/faculty_staff/Jablonski.shtml
http://www.nytimes.com/2007/01/09/science/09conv.html