Don't get it (Re: Ape to Man - where did the hair go?)

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I don't seek hair like an apes, but I do wonder why we are bare butted.

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Actually, we are not bare butted. There is hair there, but it is so fine that it is hard to feel. In fact, we have just as much hair as any other ape, but the thickness varies on different parts of the body. Next time you get goosebumps/goosepimples, just look at all the hair standing up on your arm and imagine each single strand as being as thick as the hair on your head. Just as an aside, some primates also have male patterned baldness, which might make Ned feel a little better.

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This is theory but is supported by facts we evolved from arborial apes on the plains of Africa to eventually become the domiant creature on the Earth. Evolution experts feel free to nit pick and correct my laymans understanding of this.

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Being a microbiologist, I really don't see man as the dominant creature. We are still around at the whim of our single celled bretheren for many reasons, but that is another topic for another day.The Aquatic Ape theory is also interesting, and may explain the reduction in hair thickness. Some info can be found here. I am not endorsing this theory by any means, but it is an interesting alternative to the "out into the savannah" theory. It might also explain our emotional and sexual ties to water. If I remember correctly, the current Out of Africa expansion of humans has them moving up the coasts of Africa. Anyway, just food for thought.

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But seriously, 6 wisdom teeth? Are you some kind of mutant?

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If you think that's bad, I had eight. I still hold the record at my oral surgeons office 10 years later. Too bad number of wisdom teeth doesn't correlate with wisdom, otherwise I would have hit the jackpot.Just to get back on topic, does anyone know about the variation in dentition among other primate species. I am wondering if this is a strictly human affliction.

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Man never lost the hair of the apes because man never had that much hair in the first place. Hair follicles does not equal hair! My hair follicles don't keep me warm. Don't insult our intelligence. This guy has a right to be confused listening to the crap you jokers come up with.

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Man does lose his hair, but only in the case of patterned baldness. This same patterened baldness can be seen in other primates as well. BTW, hair follicles does equal hair. We have just as many hair strands as any other ape, it is only the thickness that differs. And yes, we don't use our body hair for warmth (although we do use scalp hair). Orignally, man's earliest habitats did not require insulation. When we did move into colder climes we adapted by using skins instead of needing hair. Of course, those fig leaves wouldn't have offered the best insulation either.

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It is DEvolution to lose one's hair which is required for warmth in nearly every country except the lands where the Garden of Eden was located, where people can be warm night and day without a single hair (follicle) or scrap of clothing.

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Devolution is a misnomer. Evolution is change, no matter what the change is. Dolphins and other cetaceans also lost their hair, which was advantageous given the drag effect of hair in an aquatic environment.

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So, here's the total truth. Man was created to exist in the Garden of Eden, where clothing and hair were not required for warmth. Man was evicted from the Garden of Eden after the fall. Now man suffers in the cold and needs to wear clothes. Why is that so hard to digest?

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Yes, it is hard to digest since all of the evidence in the natural world goes against what you are claiming. You need to show evidence that man is only 6,000 years old, of which none has been presented. You might as well tell us that we are stuck in the Matrix and that the Agents planted all of the fossils.

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Science, after all these years and with all that combined intelligence still cannot explain why man lost his hair.

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Which is why there are still paleoanthropologists, biologists, and geneticists working within the sciences on that very question.

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Many aquatic animals didn't need to lose their hair to enter the water - otters, platypus, most mammals in fact. The question is why humans supposedly followed the path of the dolphins and not the otters.

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Otters, platypus, and most mammals do not spend their entire lives in the water like whales, dolphins, and porpoises. They also don't depend on bursts of extreme speed in the open ocean to capture prey. Otters feed on sear urchins (slow), walruses feed on clams (slow). However, seals do capture faster prey and are more streamlined than the others. Also, the less hair, the less drag, the less energy expended when swimming. For totally aquatic mammals this is a decided advantage while partially aquatic mammals still need fur for insulation when they are out of the water.Getting back to humans, you are right that dolphins hairlessness and skin are different than humans, and for good reason. They live in different environments. However, as noted by Crashfrog earlier, lack of hair allows us to rid our bodies of heat through sweating. This allows humans to move long distances without overheating, and therefore hunt more prey or use different hunting techniques than feline/canine predators which pant to get rid of excess body heat.

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Unlike the skin of aquatic mammals, human skin quickly becomes waterlogged (i.e. wrinkled fingers and tootsies), an obviously undesirable trait for a purportedly aquatic animal.

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Being a landlubber my whole life I was wondering, does skin wrinkle up in sea water like it does in fresh water? I was under the impression that osmotic differences led to the wrinkling effect, but I could be wrong. And also, I never said that humans are an aquatic species, although I did mention that there are theories out there that make that claim. There is a separate thread on the "Aquatic Ape Theory". It isn't that well evidenced and ignored by the majority of biologists.

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Science is merely in the process of discovering how great and mysterious this world, and we human beings, really are. Science is just a little crawling baby in the belly of something it can only say "mama" to. Science will eventually merely DISCOVER God, not disprove Him.

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This is getting a little off topic, but if you want to talk more in this area the "Is It Science?" forum is a great place to start. You seem to be hitting on what science is, investigating the natural world through natural mechanisms (such as bacteria causing disease instead of evil spirits). However, I don't see how science can ever address the existence of a diety using natural mechanisms in the natural world. Anyway, if we continue down this road in this thread we will probably get a stern warning so I'll leave it there.

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Humans also do not live in the water. At most, we waded to get food. Humans don't have bursts of aquatic speed. At most we waded and maybe did a little doggie paddle.

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Totally agree.

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It is debated that hair actually protects from the sun and even desert camels are furry as are most African Savannah mammals.

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Increased melanin protects us from harmful UV rays in absence of fur. Camels actually use their fur to insulate themselves against the heat, and they are able to withstand increases in body temp unlike humans (at least this is what I remember from my mammalian physiology course 10 years ago). Camels then release the heat during the night. If I remember right, if you shave a camel they will die of heat exposure during the day due to the lack of insulation, much like ice in a cooler will last longer than ice out in the open.Humans use a different technique, using evaporative cooling instead of releasing the heat at night. Other animals are less active and therefore are able to cope with the heat by resting in the shade or limiting their exposure to the sun (such as lions and other predators). Humans actively hunt during the time other predators are resting, and use a technique somewhat like wolves in North America. They wear their prey down instead of ambushing them or running them down. Increased evaporative cooling due to thinner hair makes sense in this scenario.

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Another argument is that hair loss facilitates sweat cooling. However there are animals like the Patas monkey that manage to sweat very effectively without hair loss.

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Do patas monkeys chase down prey in the open savannah for hours at a time? If not, then it isn't a proper comparison. From here: Patas monkeys are foragers, not open savanna hunters. They use their speed to escape from predators, not for hunting. Therefore, they don't create large amounts of internal heat due to extended running while hunting.

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Why lose the hair? Unless you're a very big beast like an elephant or a whale where sheer size makes your surface area too heat-attractive or a water-rocket like a dolphin.

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Just as a sienote, elephants cool themselves off by flapping their blood filled ears. Their large ears act as radiators. But you are right, the ratio of volume to surface area poses a problem for large animals in hot climates, but the elephant has overcome this problem by using their large ears.[This message has been edited by Loudmouth, 04-27-2004]

pbaylis,There is an utlra marathon run in the middle of Death Valley, with temps exceeding 110 degrees F. The race is 135 miles long. The records for the course are listed below--Course records: Men’s: Anatoli Kruglikov, 2000, Russia, 25:09:05. Women’s: Pam Reed, 2002, USA, 27:56:47I would say that humans are well adapted to running long distances (135 miles in about a day) in very hot conditions (110+ F). Being that humans would have been running on a regular basis to capture prey it is not unreasonable to assume that they were in better physical condition than we humans today (especially in the US).Your argument that humans can not run long distances in the heat is refuted.Secondly, humans can run down herbivores in the heat. There are first hand observations that back this up. Again, another "point" for my position.So, to sum up, no other primate that I no of runs down prey over extended distances in order to eat them. All other primates have more hair than we do. Evaporative cooling is increased with less hair. Increased evaporative cooling could allow a primate to run over extended periods, exceeding the length of time prey species can run without succumbing to heat exhaustion. Therefore, minimal hair coverage allows humans to run for extended periods of time which allows them to catch prey that can outrun them in the short term. Hair loss is an advantage in the open savanna of Africa. Advantages are kept within a population due to natural selection.Also, increased brain power is also an advantage given to us by our genetic makeup. It is no different than sharp teeth for predators or agility for herbivorse for escaping predators. It is our adaptation, and a very good one to boot. Our intelligence has allowed us to live in every climate on earth, which overcomes our hairlessness as a disadvantage in colder climes. There is no need for humans to become hairier in colder climes, especially given the fact that increased subcutaneous fat is a much better adaptation (as seen with Eskimos in Alaska).[This message has been edited by Loudmouth, 04-28-2004]

Lam,Just a friendly suggestion. Try to use evidence instead of insults when confronting posters who may not have the same background information as yourself. Sometimes it is better to take the high road, even when being insulted yourself. I have fallen in the trap of exchaning insults here on this site, but I try to avoid it at all costs. Frustration is never a good reason to abandon logic. Again, just a friendly suggestion from a non-admin regular poster. No reply nor extended discussion needed.

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These adaptations clearly have advantages so why is it so hard to accept humans evolving from an hairy, grunting ancestor?

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I think the plausibility of an adaptive evolutionary pathway and the plausibility of man's ape ancestory are two different issues for most creationists. If we were talking about how a cat species lost its hair I would venture a guess that many creationists wouldn't argue (as long as the cat was still placed in the cat "kind" ).

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the lessening of hair noticability could be a product of sexual selection rather than natural selection. humans became very aestetic creatures after they took over from neanderthal.

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There are many examples of courtship practices that reinforce advantageous characteristics. For example, deer face off mano y mano in a clash of antlers with the winner claiming a harem of does. Therefore, the strongest, and therefore most ablest to defend against predators, wins by using a characteristic that is both sexually and environmentally advantageous. In our near ancestors, the ability to run long distances in the heat was an advantage. Therefore, females made the connection (either counciously, subconsciously, or instincually) that less hair meant more food. If this was a heritable instinct, then women who latched onto hairless men instinctively would make up a larger and larger portion of the population over time until the trait was established population wide.Of course, this is just a hypothesis, but it is one way in which sexual and natural selection can work hand in hand in a way that reinforces environmental fitness.

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what does less hair have to do with more food?

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This was covered earlier in this thread so I'll just give a brief summary. Humans have the ability to run for long distances in extreme heat (95+ F or 35+ celcius). This is due to evaporative cooling by sweat. If we were covered in hair, this evaporative cooling would not be as effective. This allows humans to chase down prey animals for long distances, to the point where the prey animals collapse because of heat exhaustion. At this point, all the hunter has to do is walk up and hit the animal over the head with a stone axe. Therefore, humans have the advantage of eating prey species that can outrun humans in the short term, but lack the endurance due to ineffective body cooling. This type of hunting tactic is used in the open savannahs of Africa.

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This is probably out in left field but could our ability to use fire have any bearing on affecting our amount of body hair? The greater the amount of body hair the greater the likelihood of burns and infections in a time when antibiotics were not a common item.

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Out of left field as well, but cooking meat could have killed infectious microorganisms in the meat. Plus, you have to catch the animals before you can cook them, therefore less hair would have been linked to hunting before cooking with fire. Of course, this is just my opinion. Could be wrong.

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While I am sold on the evaporative cooling hypothesis of hair loss, it might not be pointless speculation to look at the selective factors that led to several families of scavenging birds to independantly lose feathers on part of their bodies. I strongly believe that our ancestors may have been good hunters but were excellent scavengers.

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And . . .

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It would seem to me that with the selective pressure for hairlessness (I recognize the hair is still there) it would seem to me there would be some social effects because of the importance of grooming in primate societies.

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I don't know if you intended these two ideas to be combined, but I can see a way to do just that. In the case of scavenging birds (eg vultures), the lack of feathers probably has to do with keeping excrement and rotting flesh out of the head feathers. In the same way, scavenging humans could have lost their hair for the same reason, keeping foul smelling things out of their fur (by losing the hair). Being that primates are into hygiene, a less "foul" smelling individual may do better in the society. As this trait is established, speech (or nonverbal communication) filled the emotional need that grooming used to fill. Left field is kind of fun once in a while.