What do you think is the difference between hair and fur?
From the above link:
Am I the only one who thinks the picture at the top right of that page looks like Ubuntu wallpaper?
Interestingly, this news article about a woman who has grown her hair to 9 feet long was just released last week.
Modern day Rapunzel
Now that doesn’t prove that “every single woman” can grow their hair to this length, but it certainly isn’t a myth that “some” women can do it.
A thought: Perhaps humans’ long hair (compared to other apes) is related to our tool use? A human with naturally short hair has an advantage when societal norms favor short hair, and a human with naturally long hair has an advantage when societal norms favor long hair, but a human with naturally long hair and a bit of flint can be attractive (and thus have an advantage) in either situation.
Artificial selection, like natural selection, results in evolution. They just operate on different selection processes.
Perhaps, and I really won’t argue the point. However, whichever definition you prefer, head hair fits neither. So, my original point stands.
Apologies for my misuse of the terminology. Perhaps the question should be rephrased this way: “What pressures result in in long hair through natural selection?” This eliminates the discussion of all the examples of animals who evolved it through artificial selection, which, if I understand it correctly, is not what the OP is asking.
I would agree, by the way, with the posters who implied that it’s merely sexual ornamentation, like the bright coloration of birds. In my – perhaps limited – understanding, not every trait evolves in direct response to outside pressures: some result only from intra-species competition from sexual reproduction.
In other news: The 1980 ‘Aquatic Ape Hypothesis’ Dope Column.
Nitpick: You are wondering if there are any hypotheses, not theories. A theory would be a hypothesis that had been well tested and was generally accepted by scientists to be correct. We don’t really have the capability to thoroughly test a hypothesis about why human hair can grow as long as it does. We don’t, for instance, even know when that trait emerged from the more basal condition shared by our great ape cousins.
Keep that in mind when creationists insist that evolution is “only a theory”. They would be right if it were “only a hypothesis”, but “theory” is as good as it gets in science.
Thank you so very much, John, for pointing out my use of the word theory in the popular sense rather than in the scientific sense.
So the predominant hypothesis is that very early human decided long hair was sexy, but no other apes did?
And there are no hypotheses as to why hominids hankered for hair while other hominidae did not?
I am not an anthropologist, but I keep abreast of the trends and do read a lot of scientific journals. Frankly, I’m not aware of any well-thought-out hypothesis on the hair thing. Note that most modern hunter/gatherers keep their hair fairly short, or at least do cut it rather than letting it grow indefinitely. You really only see long, elaborate hairdos in fairly advanced societies.
Going by Cecil’s “to put ribbons in” hypothesis, I imagine other apes did not have the dexterity to do so.
This would seem to indicate that “tool use” evolved prior to “long hair”…
Growing Dreadlocks is different than growing unlocked hair. With dreadlocks, shed hair is locked into the strand, as opposed to falling out. This contributes greatly to the overall length. The hair closest to the scalp may be significantly shorter than the total length, but is locked into the dread. Hair that is furthest from the scalp may have been shed long prior, but is also locked into the dread, just as the actively growing hair.
That is not to say that all people with locks can grow 9 ft. locks. Some can, some can’t. However, locks themselves normally contain hair that is technically not still growing. Growing unlocked hair is a bit different. The hair is still attached to the scalp, and possibly still in the growing stage.
Horses have manes & tails that grow long, but not indefinitely.
For each horse, there seems to be a set length that their mane or tail will grow before stopping. The length will vary by breed, and even by individuals within the breed. But it’s clearly genetic; length (and thickness) of mane & tail runs within family lines. There are of course individual exceptions, but in my breed, Morgan horses, there are specific bloodlines that are known to produce horses with a long, flowing mane & tail.
And this is exactly the same for humans.
Nitpick: hair doesn’t “know” what length it is, so it doesn’t “know” when to stop. It just tends to fall out after a certain average interval of growth.
What are you “quoting” there? t-bonham@scc.net didn’t say the hair “knows when to stop,” he said it stops. A candle doesn’t “know” when to burn out, it just burns out.
Sorry, my addition of “knows” wasn’t meant to be an actual quote of bonhams. I just saw words like “set length” and “stopping”, and just wanted to clarify, as it’s a popular enough misconception for Cecil to write a column about it.
They don’t care about appearance much at all. Human males are much pickier about women, probably because we are largely monogamous - if you are going to stick with a female indefinitely, you want one that’s young, healthy and with good genes. So, we care more how she looks.
To the best of my knowledge, in both dogs and horses, the potential for the very long hair in those breeds that have it was not what was being selected for. I believe you are committing a logical fallacy in attributing the characters to intentional selection.
Both the Afghan Hound and Komondorok (Hungarian plural of Komondor) were selected for survival and fitness for a particular use in climates which are at least seasonally harsh and unpleasant. I think you’re confusing the cultivation of those accidentally acquired characteristics by modern American breeders and exhibitors with those characters having been intended. The Afghan was used for hunting in the mountains of Afghanistan, where the winters are extremely harsh. The Komondorok were flock protectors on the plains and in the mountains of Hungary which also have very harsh weather. Pulik, another Hungarian breed, also have the extravagantly long, corded coats, as they, too, were working dogs in the same harsh* high plains winters. Why the Kuvaszok (a third Hungarian working dog breed) did not develop the long, corded coats is unknown, as they were also working dogs in the same climate. Kuvasz do have quite long coats, but they neither cord, nor do they grow so extravagantly long. When Old English Sheepdogs are working animals, their coats also do not reach that great length, nor are they bouffant like the photos you see of show dogs; that’s the product of much hard work with teasing comb, sprays, gels and blow dryers. Like the Komondorok, they were flock protectors, rather than herding dogs. It was their job to defend the sheep. The herding was done by other breeds (e.g., Pulik, Collies [yet another breed with extravagant coats - though not exceptionally long ones - when carefully tended]).
Please note that I am not making the same assertion for the Maltese and other toy breeds (“lap dogs”). They were always bred as companions for people who did not themselves work for a living. In those breeds, characters which made them distinctive - whether very long hair (or none), or some physical distortion - were selected for on the whim of the creators of those breeds. And that’s what you appear to be attributing equally to dogs which were required to perform a specific function in the lives of their owners subsisting in unpleasant climes in return for their keep.
As for the retention of shed hair in corded coats making them appear longer, I’ve seen Komondorok and Pulik (or at least photos of them) with coats which were maintained in an uncorded (i.e., combed out) state, but they still had coats that, with careful maintenance, hit the ground.
All of those dog breeds with naturally very long hair have always had the potential for the coats to grow that long. However, when they were working dogs, nobody was tending to the coats, and they were naturally abraded to shorter lengths in their working environments. If nothing else, the hair that brushed the ground would be worn away by that contact - or snagged and pulled loose.
The same would be true of the horse breeds which are capable of growing those luxuriant manes and tails, except that I can’t think of any survival benefit for the horse in longer manes and tails. This is unlike the very specific survival benefit to Shetland ponies in their long, shaggy winter coats, which helped them to survive the (again) harsh winters of those islands high in the north Atlantic. I don’t know whether those coats have been bred out of the Shetland ponies we see today, but I don’t think I’ve ever seen one with the same kind of shaggy winter coat that one sees in old photos of Shetlands in winter. It seems to me that the long manes and tails of those other horse breeds must be even more accidental than the very long coats of the dog breeds I cited. Only when individual animals are kept in circumstances where the manes and tails are carefully protected to grow as long as possible do they reach the rather preposterous looking lengths you appear to find irrelevant. The potential was always there, but was not realized when the animals were working members of the households of their owners. And that was the reason why I also mentioned musk oxen and mammoth.
[Last minute addition before posting: It could be that the breeds with very long manes and tails were in regions under more intense attack by flies and other biting/stinging insects. If that were the case, the longer tails could have given them a more effective “fly swatter” - so to speak.]
Were I prepared to do a bit of research, I could probably list at least another half-dozen species of wild animals which grow amazing quantities and lengths of hair, many if not most of them ones which shed out their coats annually as the seasons change. And human hair doesn’t grow anywhere near that fast. The two times in my life that my hair hit below my knees, it took several years to get that long. But I’m getting old now, and though I haven’t cut it since the second time it got that long, it is now several inches shorter. And the length may decrease as yet more years pass. I know women my age - and older - who also had much longer hair when they were young, but their hair will barely reach their shoulders now.
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*The insistent repetition of “harsh” was intended to emphasize just how challenging continuous outdoors survival in winter is in those places. There aren’t many words which are really able to convey just how miserable it is to live through month after month of howling blizzards on high plains, or the hazards of hunting game in mountains which are “weather-makers” for an entire region.