Most mammals seem fine with shorter hair (usually denser though). The only other case that comes to mind of very long hair restricted to a specific body area is that of horses manes, which to be fair I’m also not totally sure what purpose it serves. Many equines seem fine with shorter manes and tails that don’t have such long hair, like zebras. They swish flies away all the same.
Some animals have long hair but it covers most of their bodies (like llamas or yaks maybe), it’s not restricted to a small area. Other animals have denser or longer hair in some areas, like lions, but this serves a purpose (protection of the neck and head) and even then the length ratio between these longer hairs and the rest of the fur isn’t as skewed as that of humans.
So, why? I get that hair on the head helps protect it from the elements and sun, but why so long? Some humans can grow hair longer than their own body length, which is remarkable, and without doing any fact check I’d say we are probably among the top 5 species with longest hairs ever. Is it just a showoff feature like a peacock’s tail feathers, an indicator of overall health? Or does it serve another function as well?
I didn’t mean to type this wall of text…, thanks for coming to my TED talk
mech@feddit.org 1 day ago
Evolution doesn’t produce perfect adaptations, just “good enough”.
Humans lost their body hair and got more on their head when they developed walking upright in Africa.
Lets sweat cool the body down and protects the head from the sun.
At some point, something lead to a mutation that turned curly hair into straight hair, and that seems to have been selected for in populations living in colder climates.
But that doesn’t mean it increased chances of survival. Maybe it was just preferred by sexual partners for some reason, which may even have been cultural at that point.
jumperalex@lemmy.world 1 day ago
Perhaps the hair change was the result of some other gene expression that was beneficial while the hair change itself was neutral-ish.
Mothra@mander.xyz 11 hours ago
Yes I understand “good enough” and that it could just be out of whimsical preference by sexual partners. But what if not? The best answer I found here was that greasy long hair, in those cold climates, was somewhat water repellant. Nobody wants to get wet in the cold.
Klear@piefed.world 1 day ago
This reminds me of something I’ve been wondering about for a while now - burning hair has a distinct and very strong smell. That makes sense - if your hair is on fire, you want to know ASAP. My question is whether our hair evolved to have something in it that produces this smell, or if we just evolved to be particularly receptive to the smell of burning keratin.
That is of course ignoring the boring answers: “A little bit of both” and “It just worked out like that randomly”, as well as the best answer “Wait, that’s what that smell is?! Oh shit, you’re right, I’m burning! AAAAAAAA!!!!”
myrmidex@belgae.social 1 day ago
You had it: people whose hair didn’t smell when burning died more often, skewing the chances of survival towards smelly-when-on-fire hair.
Swaus01@piefed.social 1 day ago
It feels cool to have curly hair despite being from a long line of cold climaters.
ShellMonkey@piefed.socdojo.com 1 day ago
Way I figure, the common traits for any given part of the world where as much influenced by the isolation of groups as environmental factors. Back in primitive times it could take months wandering before you happened across another group, and even then there may be ‘untrusted tribe’ type conflicts.
It still shows up today in how rural isolated communities tend to foster more prejudiced attitudes towards people different from them. But now we can move all over quickly and communicate instantly, so there’s a less concentrated effect by location. Plus the whole advent of ordered society and the host of factors that brings into play.