I go to California for the holidays, and when it comes time to return to the Northeast always ask myself how I’m going to make it through the upcoming winter months. I’ve wondered this of others, too — friends from Chicago, friends who live in Norway, Inuit who live in Greenland. A new study might have an answer: Inuit, at least, seem to have a gene variation passed down from our ancestors that helps them produce more heat.
In a study published this week in the journal Molecular Biology and Evolution, researchers analyzed the part of Inuit genome that affects body fat distribution. (They looked at the genome of nearly 200 Inuit.) They compared this portion of Inuit genome with the same portion of other populations, as well as Neanderthals and Denisovans, which are another one of our ancestors that interbred with modern humans about 50,000 years ago.
All Inuit had a gene variation that helps them build more brown fat. Unlike white fat, which just contains calories, brown fat burns energy and produces heat. It’s helpful for adapting to the cold, and is especially common in babies. Most interesting, though, this specific pattern of gene variation matched very closely with the same genome portion of the Denisovans, suggesting that Denisovan ancestors are the source of this evolutionary advantage.
The results should be taken with a grain of salt, since only one Denisovan genome has been sequenced, so there’s not that much to compare. Still, it’s an interesting finding and one that makes me feel slightly better about my personal weaknesses when it comes to dealing with cold.