The Coevolution of Lice & Their Hosts 179
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."
Gorilla / Human lovin'? (Score:3, Informative)
Did anyone else read that line and think that this was article could have some link to the Monkey's Uncle [slashdot.org] (proto chimp/proto human interbreeding) story from a while ago on slashdot?
Afraid not, TFA states: Anyway, best article linked from
I'm going to wonder whether there were savanna gorillas or deep Forest hominids all night now
Rather than read a second-hand account... (Score:5, Informative)
Conclusion:
Re:Timing when we lost our hair (Score:2, Informative)
I think horses can usually outrun humans even for long distances. See also: Man versus Horse Marathon [wikipedia.org]
Re:hair shape (Score:4, Informative)
Re:Gorilla / Human lovin'? (Score:4, Informative)
It's an excellent article, but the summary makes no sense, which at least encouraged me to read the article to figure out what the hell they were talking about. For example, from the summary:
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.
1) What is "unsettling" about this? Anyone? No prior deeply held beliefs have been overturned. No profound conceptual schemes have been shaken to their very foundations. Parasites are known to be highly specialized. This fact has been published repeatedly for decades, always with great emphasis on how apparently hard it is to believe. After a couple of decades of being routinely reminded that individual species of ticks and fleas and lice are hyper-specialized, do you think we might ask that people stop presenting this fact as something astonishingly new?
2) The statement is contradicted by the article. What the article says is that head lice and pubic lice in humans are so different morphologically that "early taxonimists" assigned them to different genera. The article implies but does not say explicitly that this early assignment was not in fact justified.
In any case, this is an absolutely fascinating, albeit tentative and partial, reconstruction of the hominid evolutionary tree from parasite DNA, and I'm sure that as more data from different parasites becomes available we will be in for some real surprises. Internal parasites that are less likely to be passed between species should provide a record that is clearer than the lice record, where despite the relative paucity of inter-species transfers the record has clearly been muddied several times.