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The Coevolution of Lice & Their Hosts
eldavojohn writes "It might be an uncomfortable subject but parasites are an interesting subject when it comes to evolution. Ever wonder if pocket gophers have lice? Well, they do. And most interesting of all is the evolution of these lice mirroring the evolution of gophers. To study the genes of lice may shed just as much light on evolutionary trees as studying the genes of the actual host the lice has evolved to. The most unsettling result from these studies is that human head lice and human pubic lice (crabs) vary so greatly that they are in two separate genera. There were similarities between our pubic lice and the lice found on gorillas. Scientists came to the conclusion, which they published today in BMC Biology, is just as striking as their earlier one about head lice. But it is hardly the same. We did not get pubic lice from other hominids. We got them from the ancestors of gorillas."
Further to that...
What the fuck is a pocket gopher?
From the article: "And then there is the matter of where the lice live. Today, lice live on little islands of hair on an ocean of hairless human skin. They are clearly adapted to our relatively hairless bodies. The authors suggest that their results may mean that hominids were already losing hair 3.3 million years ago. The gorilla lice needed an empty ecological niche--pubic hair--that they could occupy in order to survive. If hominids had full-body hair, the lice that already lived on it might have been able to outcompete an invader."
In my opinion this is one of the most interesting aspects of this research - being able to date when we started becoming hairless. It's always been a puzzle why we are relatively hairless compared to the other great apes, and I would guess that being able to put some time constraints on it is a step toward understanding how this happened.
It looks like its an arms race then.
That's exactly what parasite-host relationships are. Evolution isn't so much a march in a straight line, but a vicious cycle of decimation-immunization-regression to naivete-back to decimation, ie, the Red Queen hypothesis. The really interesting thing is the degree to which parasites have affected evolution. A lot of secondary sex characteristics, because of their biological expense, are really good indicators of parasite resistance.
The coevolution of parasites and their hosts is admirably exemplified by the hordes of clueness do-nothing know-nothings who rush to offer hilariously foolish comments on slashdot.
1. Humans evolved from the same primates as gorillas, and the lice just stuck with us the whole time.
2. Some human had sex with a gorilla.
Sigh. Another sheep argument with Irreducible Complexity. None of the candidates for this kind of "Gap" theology have stood up to scientific analysis. Other sheep have argued in a similar manner about the eye, the flagella, etc.
I wish Richard Dawkins was made required reading for all the misguided lambs every Saturday night before churchday.
Hand in there my friend, there is still hope. You can be saved.