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asharpwone

asharpwone's Journal
asharpwone's Journal
May 22, 2015

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May 22, 2015

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May 18, 2015

Welcome Home: Justin Gaertner - "This Old House" special

Corporal Justin Gaertner served as a Combat Engineer and a minesweeper in the U.S. Marine Corps. He was critically injured in an IED blast, requiring the amputation of both legs. In this video, Justin describes how his new accessible house, provided by Homes for Our Troops, has changed his life.


May 5, 2015

How Europeans evolved white skin

ST. LOUIS, MISSOURI—Most of us think of Europe as the ancestral home of white people. But a new study shows that pale skin, as well as other traits such as tallness and the ability to digest milk as adults, arrived in most of the continent relatively recently. The work, presented here last week at the 84th annual meeting of the American Association of Physical Anthropologists, offers dramatic evidence of recent evolution in Europe and shows that most modern Europeans don’t look much like those of 8000 years ago.


...

The paper doesn’t specify why these genes might have been under such strong selection. But the likely explanation for the pigmentation genes is to maximize vitamin D synthesis, said paleoanthropologist Nina Jablonski of Pennsylvania State University (Penn State), University Park, as she looked at the poster’s results at the meeting. People living in northern latitudes often don’t get enough UV to synthesize vitamin D in their skin so natural selection has favored two genetic solutions to that problem—evolving pale skin that absorbs UV more efficiently or favoring lactose tolerance to be able to digest the sugars and vitamin D naturally found in milk. “What we thought was a fairly simple picture of the emergence of depigmented skin in Europe is an exciting patchwork of selection as populations disperse into northern latitudes,” Jablonski says. “This data is fun because it shows how much recent evolution has taken place.”

Anthropological geneticist George Perry, also of Penn State, notes that the work reveals how an individual’s genetic potential is shaped by their diet and adaptation to their habitat. “We’re getting a much more detailed picture now of how selection works.”

Fascinating combination of recent studies in relatively recent evolution, (last 8,000 years).

http://news.sciencemag.org/archaeology/2015/04/how-europeans-evolved-white-skin

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