18/03/2010 § Leave a comment
Part One. Presented by Evolutionary Biologist Steve Jones
BBC World Service, Programe: Discovery
Aired 11/4/2010 (audio fail no longer availiable)
“if we were to talke a walk , a long walk from England over the channel, though europe into western asia, into eastern asia, and then were to double back on ourselves and to travel though the mediteraninan region into africa. What we would see are gradual changes from one human population to another. So yes, we see diffeneces from one extreme to another but those diffences grade gradually from one another, differences in skin pigmentation and other physical features. And so this clearly indicates that this veriation is like a gradient, its clinal in its distribution and there are very few if any abrupt discontinueties that would allow us to erect any distinct ratial or other named categories.”
Nina Cheblonski, Pincelvania University
Why did we go light coloured? – to capture precious uvb to produce Vitamin D and make us reproductively productive.
“Western Europeans clearly had this mutation but equally lightly pigmented eastern asians did not. the conclussion then was: people in aisia had lost pigment independantly, so this has now happned twice then in modern population.”