Alpine dogs and Arctic people - Dec 22, 2011

It was 24°F when I took Anya around the park near my son's school. She did her business, and I briefly let her off-leash to romp with two spaniels who were visiting from up North. She just wanted to roll around in the snow-dusted grass and sniff things.

St Bernards were bred as mountain rescue dogs, though their value as such was diminished when they were cross-bred with Newfoundlands in the 1820's, to save a breed decimated by avalanches in 1816-1818. Their fur became long like Newfoundlands', making it likely to be weighed down by snow.

Nevertheless, they are not hot-weather dogs. Anya drooped all summer, camping out in front of the air conditioner. Now? She romps in the snow, sniffing (looking for people buried under the avalanches?). She will happily bat around chips of ice for hours. She thinks she's back in the Alps.

It's stories like this that have made it tempting to say that people genetically adapt to their environment: that Inuit are somehow genetically set up for life in the Arctic, or Indonesians for life by the Equator. Evidence says otherwise: Inuit resilience to cold is largely due to diet—probably a blubber allergy would be trouble for an Inuit living in the traditional Inuit way, but if you feed them typical "western" food, their cold resistance is about the same as any of us. And people who live in the tropics largely just adopt clothing, daily habits, and diet that make their lives more comfortable.

So, it's our flexible brain, not our other physical genetic adaptability, that has made humans able to live in such a huge variety of climates. In this, we are unusual among animals, at least if you think of the brain as somehow different from other parts of the body. We do adapt, but we adapt in large part by taking bits of the world around us, and shaping those in turn to make clothing, shelter, and other tools to shield ourselves from a changing environment.