Published on January 29th, 20140
When Did We Get The Light-Skin Gene? 7,000-Year-Old Human Bones
A European hunter-gatherer who lived 7,000 years ago in the present territory of Spain, had dark skin and blue eyes, according to a genetic study, suggesting that light skin arose much later than that.
The results also suggest that light-skin evolved not to adjust to the lower-light conditions in Europe compared with Africa, but to adapt to the new kind of food (cereals) occurred after the agricultural revolution, says one of the study authors, Carles Lalueza-Fox, specialist in paleogenomics at Pompeu Fabra University in Spain.
According to this theory, eating cereal after the agricultural revolution, who supplies the body with less vitamin D, so it become useful to have light-skin, allowing more efficient synthesis Vimin D under the influence of solar radiation. The study results were published in the journal Nature.
For a long time it was thought that light-skin arose gradually in European populations 40,000 years ago, soon after humans spread from tropical Africa to higher latitudes.
But the new discovery shows that this change would have occurred only 7,000 years ago, so at least some humans lived considerably longer than thought in Europe long before losing the dark pigmentation that develops in the sunny conditions of Africa.
The new results suggest that not only latitude caused the change in skin color of Europeans. If it were so, then light-skin would have to be widespread in Europe several millennia earlier.
The analyzed skeleton was discovered in 2006 by hikers in the mountains of Cantabria in Spain.
At the time, genetic research techniques were not advanced enough to allow accurate extraction and analysis of DNA. A few years later, with the progress of analytical methods, the DNA could be extracted and studied of the skeleton’s molar.
The analysis shows that the man possesses a genetic mutation associated with the presence of blue eyes, but it was not the mutation that gave Europeans pale skin. The results also show that the man was more more related to the modern Europeans in northern Europe than southern Europeans.
The discovery could explain why blue eyes are more common in Scandinavia. It is believed that in northern Europe, harsh weather conditions delayed the agrarian revolution so that Scandinavians may have more features retained by their hunter-gatherer ancestors, including a random blue-eye mutation that emerged in the small population of ancient hunter-gatherers, said Lalueza-Fox.
Source: Live Science / Credit image: CSIC