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5 December 2013 11:26 am ,
Vol. 342 ,
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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ScienceShot: Tanning Ability Driven by Evolution
22 June 2010 4:18 pm
Sunbathers who bronze beautifully have natural selection to thank. Research published in the Proceedings of the National Academy of Sciences suggests that the ability to tan is a trait that evolved several times in mid-latitude regions, such as China and the Mediterranean, where the sun's intensity varies dramatically from season to season. If inhabitants of these regions had consistently dark skin, which blocks the sun's rays, they wouldn't have produced enough vitamin D in the winter. If they had consistently light skin, their bodies would have been robbed of folate, a light-sensitive vitamin essential for cell division and repair. Folate is especially important during pregnancy; too little can result in birth defects. Indeed, the researchers posit that sun-induced folate deficiency, rather than skin cancer or sunburn, was the driving force behind the evolution of dark skin and tanning.
See more ScienceShots.