Cold tolerance among Inuit may come from extinct human relatives

Did you see this? From the NYT: Cold tolerance among Inuit may come from extinct human relatives.

Inuit who live in Greenland experience average temperatures below freezing for at least half of the year. For those who live in the north, subzero temperatures are normal during the coldest months.

Given these frigid conditions, anthropologists have wondered for decades whether the Inuit in Greenland and other parts of the Arctic have unique biological adaptations that help them tolerate the extreme cold.

A new study, published on Wednesday in Molecular Biology and Evolution, identifies gene variants in Inuit who live in Greenland, which may help them adapt to the cold by promoting heat-generating body fat. These variants possibly originated in the Denisovans, a group of archaic humans who, along with Neanderthals, diverged from modern humans about half a million years ago. [continue]

Why we walk on our heels instead of our toes

From Why we walk on our heels instead of our toes.

James Webber took up barefoot running 12 years ago. He needed to find a new passion after deciding his planned career in computer-aided drafting wasn’t a good fit. Eventually, his shoeless feet led him to the University of Arizona, where he enrolled as a doctoral student in the School of Anthropology.

Webber was interested in studying the mechanics of running, but as the saying goes, one must learn to walk before they can run, and that—so to speak—is what Webber has been doing in his research.

His most recent study on walking, published in the Journal of Experimental Biology, specifically explores why humans walk with a heel-to-toe stride, while many other animals—such as dogs and cats—get around on the balls of their feet.

It was an especially interesting question from Webber’s perspective, because those who do barefoot running, or “natural running,” land on the middle or balls of their feet instead of the heels when they run—a stride that would feel unnatural when walking.

Indeed, humans are pretty set in our ways with how we walk, but our heel-first style could be considered somewhat curious. [continue]

If you’ve been a reader for years, you might remember this post from 2008: You walk wrong. The article quoted there was part of what convinced me that the “expert” advice we generally receive about footwear is all wrong. (Article summary “It took 4 million years of evolution to perfect the human foot. But we’re wrecking it with every step we take.”)