February 21st, 2015
Perhaps with global warming, we won’t have to worry about surviving cold climates. Meanwhile, people still live in places like Siberia, where temperatures can run a winter average of -25 degrees C. How do they survive? A Cambridge University team has found that the answer lies in specific genes.
Alexia Cardona, a graduate student at Cambridge, and her colleagues found three genes that appear to be favored by natural selection among Siberians; one, UCP1, had been discovered in 2010, are more active in people living in colder areas, and direct the body to transfer fat stores to directly produce heat (instead of supporting muscle movements or brain function). The other two were ENPP7 and PRKG1; the former is involved in metabolism in fats from meat and dairy products, a big part of the Arctic diet, and PRKG1 helps smooth muscle contract, which enables shivering and blood vessel constriction, which reduces heat loss. Cardona presented her findings at the Unraveling Human Origins conference in Cambridge in January.
Cardona and her colleagues studied 200 DNA samples collected from native Siberians, including members of the Teleut indigenous people, who number 2,000 and may be in danger of disappearing. While the study underscores how natural selection can aid in survival and adaption to adverse conditions, it also shows how different people find different ways to adapt; her study found stronger selection for the UCP1 gene in southern Siberia, while selection for the ENPP7 gene showed stronger selection to the north and eastern parts of the area. Selection for PRKG1, however, appeared to be universal.
Since these genes do exist in all humans, the study may help us understand how people can survive in more “temperate” areas, like Scandinavia, Canada, and Alaska.
Photo: ScienceNow, Arkady Zarubin/Wikimedia Commons
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