This holiday season I received no less than five sweaters, one space heater, a fleece lined sweatshirt, and one wonderful electric blanket. Why? It’s very well known that I’m constantly freezing. My teeth have even been known to chatter at the balmy 60 F, the same threshold at which my mother allowed my brothers to wear shorts while we waited for the school bus as kids.
A study published recently revealed something I’m clearly missing: a cold-tolerant gene. This gene variant, possessed by the Inuit, Native Americans, and some Siberians, is thought to cause “a certain type of body fat known as ‘brown fat’ to generate heat,” in addition to being involved in other traits like body fat distribution, bone, and facial structure.
This gene variant is very similar to a gene sequence found in the Denisovans (“extinct humans who once ranged from Siberia to the Southeast”). An earlier discovery had proposed that the Tibetans had also inherited a variant from the Denisovans, which allowed them “to use oxygen efficiently when the air is thin at high altitudes.”
Prior to this study, it had been recognized that one of the clusters of genes involved in cold tolerance was “significantly associated with different phenotypes including fatty acid profiles, weight, and height.” That had been notable, when considering cold-tolerance, because “short, stocky stature was an evolutionary adaption for cold weather since it consolidated heat.” Unfortunately, I don’t seem to be consolidating heat that way.
Another factor working against me is that women seem to feel cold more often than men (this comic by Blue Chair notwithstanding). Many people have observed anecdotal evidence for this, but researchers also found that women tended to possess higher core temperatures, but have consistently colder hands and feet—possibly leaving them feeling colder.
All in all, it looks as though I’m going to continue shivering, but at least now I have some answers.
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