Why humans have so little hair compared to other apes

[JSF]

Here’s another possibility:
It’s known that some apes get so much fur care from the other apes in the community that they lose patches of hair. These apes with bald patches are socially important apes, apes that everybody wants a good standing with (and hence maintains their fur).
So this may very well be associated with attractiveness.
Voilà, there’s less fur as an evolutionary advantage.

[anon75430791]

Yep. I have read that there is some Ultramarathon in Mexico or something where they race horses against the humans.

When it is really hot out, the humans tend to win.

[RedFury]

@Ratel

Yeah, that worked out great. Now humans are special in the animal kingdom for supporting two different species of lice: one for our heads and one for our bodies. And that’s not even going into varieties crotch crickets.

Thank you for referencing that. One of the voices in my head was yelling that while I read the post.

[LurksNoMore]

@Ratel

Bdaaagh! Again, total fucking bullshit. We have color discrimination because we share it with all of our hair-covered primate relatives, who need it because they are largely frugivores or transitional herbivores who need red/green distinction to assess the ripeness of fruit and the toxicity of leaves. Was this published on April first, or is this a proud graduate of the Pat Robertson College of Biology?

Tangentially, that’s why humans (and IIRC other big apes) can’t synthesize vitamin C – our ancestors were to a great extent frugivores, so their diet was rich in vitamin C, and the loss of the metabolic pathway to make your own was not selected against.

[JSF]

see https://www.youtube.com/watch?v=826HMLoiE_o

[karl_jones]

@MadLibrarian

Old Man Dingo to the contrary, most predators are sprinters. Fit humans, as it turns out, are marathoners.

“What are you running from, apex predator … Are you chasing prey? You need to conserve energy.”

Jake Likes Onions

[lava]

in other words, nobody knows.

[Dug_Rusin]

So then I’m not a sweaty balding guy, but rather the next step in our evolution?
I like it!

[anon41977465]

actually how thick would hair around the genitalia have to be to hide the ‘emotions’?

[Melz2]

For some reason, this post reminds me of The Bear That Wasn’t.

“You’re a silly man, who needs a shave and wears a fur coat.”

[smut_clyde]

@Ratel

Bdaaagh! Again, total fucking bullshit. We have color discrimination because we share it with all of our hair-covered primate relatives, who need it because they are largely frugivores or transitional herbivores who need red/green distinction to assess the ripeness of fruit and the toxicity of leaves.

That’s just one of Changizi’s Just-So stories. He has also claimed that our fingers and toes wrinkle after long immersion in water as an adaptation for better grip while foraging for shellfish. And that music co-evolved with human brain function (western music, anyway).

For a while he was selling special mind-reading spectral-filter sunglasses that would improve our perception of skin flushing and make the buyer into a better poker player.

My love is like a red red nose His tail is soft and tawny *

[Bucket]

@docosc

This is the most convincing argument I have heard about hairlessness and sweat glands. In the absence of teeth and claws, we developed the ability to literally run our prey to death, and to do so in the heat of the day when most other predators are waiting it out in the shade. It makes logical sense, but since behavior does not fossilize, it remains a hypothesis that is pretty difficult to test.

This is my personal favorite hypothesis. After four months of training even I was able to run a marathon, and I’m about the most average schlub you’d ever meet. Only ostriches* can beat humans over distances like that, which makes sense if they were one of the things we were chasing around for tens (hundreds?) of thousands of years.

*And apparently pronghorn sheep and camels. Also sled dogs but they don’t count because that was us breeding them for that, and I doubt malamutes & huskies could run a marathon in Texas without spontaneously combusting. Horses might be able to or might not, but also bred by humans to be like that. But the list is still extremely short, especially when compared to the list of animals that could kick our asses over shorter distances.

Also holy shit camels are crazy.

[Keith_McClary]

When anthropologists don’t know what something is for, they say it is a religious object.

When biologists don’t know what something is for, they say it is to attract mates.

[smut_clyde]

The cursorial-hunting hypothesis also fits in with Lierberman’s ideas on the evolution of the muscular human bum:

(though Lieberman saw our ancestors as carrion eaters, competing with jackals and vultures, so they needed to run long distances in order to reach a carcass first).

At any rate, that particular just-so story is OK, because it lets me observe that “evolution leaves no stern un-toned”.

[Lexicat]

I found a different version of that story in semi-animated form. Is it part of a collection?

[Melz2]

@Lexicat

a different version of that story in semi-animated form.

The Chuck Jones short is the only animated version that I know of.

[fnordius]

I do recall seeing some documentary where they demonstrated that it wasn’t so much raw endurance that counted, but endurance in midday heat conditions. There are still humans that hunt that way in the Namib desert: “nonchalantly” chasing the prey enough to not let it rest or pant, until it falls over from heat exhaustion. Superior cooling over superior speed, or superior endurance in less hot conditions.

Granted, this has less to do with the loss of pelt and more to do with the unique sweating humans do, but less fur interfering means evaporation can better cool the capillaries in the skin.

[Glaurung]

@anon75430791

“You ever notice how un-fuckable really hairy guys are? Applies doubly so to women. Well generation after generation the less hairy ones fucked more and here we are mostly hairless.”

Lots of evolutionary biologists would agree with you, including Chuck Darwin himself.

The Descent of Man, and Selection in Relation to Sex

Every time I see an article like this that strains to invent “just so stories” for why this or that human trait would be adaptive, I groan and shake my head. Especially when the “just so” stories are being uttered by biologists who should fucking know better.

The fact that body hair is a secondary sexual characteristic should be a clue that where and how we are hairy vs. where and how we are not so hairy has to do, first, with what our extremely distant ancestors found hot and sexy, and only second with what was adaptive or non-adaptive.

Ditto for whether or not we have dark or light skin, and double ditto for our hair texture and colour and our eye colours. In the case of Melanesians, the cause of their having a lot of blondes has been traced to random mutation of a single gene, which then became very common because, like the Vikings, Meanesians thought blonde hair was hawt.

My Title

We know that our ancestors passed through an extremely narrow poplulation bottleneck on the way to becoming human. In a small founding population, it’s very easy for a few random traits, like not having very much hair, to become ubiquitous simply because at the time they were seen as sexy.

[Brainspore]

@anon75430791

You ever notice how un-fuckable really hairy guys are?

I get this is tongue-in-cheek but obviously that varies by culture and time period. Think Tom Selleck, Burt Reynolds, and all but the most recent James Bonds. All the biggest male sex symbols used to sport chest pelts.

[Melz2]

@anon75430791

You ever notice how un-fuckable really hairy guys are?

Uh… That’s a personal preference, and not even a strictly hetero one at that.

See Exhibit A: ‘bears.’