Humans are members of a weirdly exclusive club of mostly naked mammals, sharing that honorable distinction with the likes of elephants, rhinos, and whales. Mole rats, too, but they’re gross. Most mammals are hairy, and our ancient ancestors were too, but we ditched most of it at some point along our evolutionary journey. Why?
Early humans living in Africa developed more sweat glands, slowly ditching the fur in the process. In doing so, we gained the ability to endure long-distance runs that helped us become persistent hunters, creatures that could chase animals across the savanna until they passed out while we were just out of breath.
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Related on the SLP
Hair still has plenty of practical uses. It’s our natural sunscreen, armor, and an early-warning system that, for instance, can tip you off to the spider on your arm. Humans didn’t lose hair so much as we toned it down. We have all the genes to go full Chewbacca, they’re just turned off.
