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The hypothesis fails to explain why this adaption is unique to humans. Lice probably was just as big of a problem for other animals in similar habitats as it wa

by arketyp 17y ago

The hypothesis fails to explain why this adaption is unique to humans. Lice probably was just as big of a problem for other animals in similar habitats as it was for humans. The question is what element in human evolution made the benefit of not having fur greater than the benefit of having it. Sexual selection seems far-fetched. I like the idea of the discovery and invention of maintaining fire as being that element. It is known that modern hunter-gatherers hunt and catch their pray in long distances by exhausting them, and our ancestors probably did the same. Not having fur is of great advantage in this scenario as it allows for effective cooling when sweating, while the obvious down-side is freezing at night. With the taming of fire, freezing could be avoided by staying close to the hearth, and so fur was no longer needed and we lost it. I recommend "Catching fire" by Richard Wrangham for further investigations on how fire shaped our evolution. It's quite a good read, and a very interesting hypothesis. [Edit: Gave the book's subtitle instead of the real title.]

asdlfj2sd33 17y ago
I could have sworn the parasite theory is very old. I even recall genetic studies of human head and pubic lice vs. ape and gorilla lice. The genetic history of the lice matched nicely with our hair loss genes. And I have no trouble believing this, as well as hunting by running down, and sexual selection and fire all contributed to our hairlessnes. Sexual selection in particular is very powerful. It routinely spawns new species. Just one female that prefers something different in males, can quickly lead to a reproductively isolated population. Just about the only thing that I don't think is a factor is an aquatic ape phase.
- jacobolus 17y ago
  Yes, it’s quite interesting, it turns out that human pubic lice share closer ancestors with gorilla lice than either chimpanzee or human head lice do, while those species are quite close to each-other. Which means that when humans became hairless, their lice adapted to living on their heads and stopped living all over the rest of their bodies, leaving a perfect ecological niche (pubic hair) for gorilla lice to jump into. The evolution of "body lice" likewise corresponds with the earliest uses of clothing.

by arketyp 17y ago

asdlfj2sd33 17y ago

I could have sworn the parasite theory is very old. I even recall genetic studies of human head and pubic lice vs. ape and gorilla lice. The genetic history of the lice matched nicely with our hair loss genes. And I have no trouble believing this, as well as hunting by running down, and sexual selection and fire all contributed to our hairlessnes. Sexual selection in particular is very powerful. It routinely spawns new species. Just one female that prefers something different in males, can quickly lead to a reproductively isolated population. Just about the only thing that I don't think is a factor is an aquatic ape phase.

jacobolus 17y ago
Yes, it’s quite interesting, it turns out that human pubic lice share closer ancestors with gorilla lice than either chimpanzee or human head lice do, while those species are quite close to each-other. Which means that when humans became hairless, their lice adapted to living on their heads and stopped living all over the rest of their bodies, leaving a perfect ecological niche (pubic hair) for gorilla lice to jump into. The evolution of "body lice" likewise corresponds with the earliest uses of clothing.