Here's an article I've read just now:
Adaptive conundrum of swinging both ways
20 February 2002 21:00 GMT
by Bea Perks, BioMedNet News
Homosexuality, at least in female Japanese macaques, serves no function beyond sexual gratification and is simply an evolutionary by-product, suggests Paul Vasey, a Canadian primatologist speaking in London today.
But Vasey's findings fail to impress evolutionary biologist Joan Roughgarden, professor of population biology at the University of Stanford. "To show an absence of function is a tall order," Roughgarden told BioMedNet News. "One can't simply say that they have been unable to think of the function."
Vasey, postdoctoral fellow at the University of Lethbridge in Alberta, has been monitoring mating behavior of Japanese macaques for 10 years, he told an audience at University College London this evening for his talk, "Is homosexual behavior adaptive?"
All female Japanese macaques engage in homosexual "consortships," temporary but lasting sexual relationships, he said. During a period of close observation on 21 homosexual consortships, he observed 3,945 female-female mounts, "they were mounting about once every two minutes," he noted.
"The 'mounter' typically pelvic thrusts against the 'mountee,'" said Vasey. They assume a range of positions identical to heterosexual equivalents, including the "jockey" or sitting mount, and the "double foot-clasp" mount, where the mounter grips onto the hind legs of the mountee.
"The [mountee] will turn around and gaze really intently into the mounter's eyes," said Vasey. They even "lip quiver at each other," he added.
Looking for an explanation, Vasey has tested frequently suggested "sociosexual" explanations for homosexual behavior, such as asserting dominance and mediating alliance formation.
"I've tested all of the major functional explanations," Vasey told BioMedNet News, "and none of them seem to hold."
Instead, he calls on "evolutionary history." Young male macaques demonstrate sexual behavior in games, said Vasey. One male will "mount prompt" another, by putting his hands on his playmates hind-quarters, but before he gets to mount, the playmate frequently "swivels around" and mounts the initiator. It's such a well-rehearsed game, said Vasey, that male macaques end up mounting whoever tries to mount them. Female macaques have apparently worked this out and frequently mount males to encourage them to mate.
Thus, natural selection favors female male mounting, said Vasey. But how has that transferred to female-female mounting?
"They're rubbing their clitorises on the males' back, they're also mastubating with their tails," he said. "So at that point in the evolutionary scenario you have a system where females have evolved the capacity to mount and that capacity is being maintained in the population by natural selection. But they have also evolved the capacity to derive sexual gratification from mounting ... and they can mount the male and derive sexual gratification just as well as they can mount the female and derive sexual gratification."
Homosexuality among female macaques, Vasey concluded, "is a by-product of selection for the adaptation of female male mounting."
Clearly, he admitted, his findings are species-specific. Nonetheless, he added, his approach "would suggest a possible avenue for future research in humans."
Joan Roughgarden, who until Spring 1998 was Jonathan Roughgarden, is not convinced. "Paul doesn't offer any data on lifetime reproductive success," she said. "He must show that the fitness of a macaque who is homosexual is very close to the fitness of a macaque who isn't homosexual."
Functions for homosexual behavior are known in dolphins, oyster catchers, mountain sheep, and others, she says. And while these do not relate directly to human homosexuality they illustrate that homosexual behavior is a "perfectly natural activity well within the scope of evolutionary theory."
"The cause of the evolution of homosexuality in humans seems rather mysterious," she added. "I feel we need much more attention to the nature of the relationships that are built between people based in part on their homosexuality."
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I can give a few contrarian remarks about the evolutionary framework of the article, but it's a bit irrelevent.
What do you guys think?
Adaptive conundrum of swinging both ways
20 February 2002 21:00 GMT
by Bea Perks, BioMedNet News
Homosexuality, at least in female Japanese macaques, serves no function beyond sexual gratification and is simply an evolutionary by-product, suggests Paul Vasey, a Canadian primatologist speaking in London today.
But Vasey's findings fail to impress evolutionary biologist Joan Roughgarden, professor of population biology at the University of Stanford. "To show an absence of function is a tall order," Roughgarden told BioMedNet News. "One can't simply say that they have been unable to think of the function."
Vasey, postdoctoral fellow at the University of Lethbridge in Alberta, has been monitoring mating behavior of Japanese macaques for 10 years, he told an audience at University College London this evening for his talk, "Is homosexual behavior adaptive?"
All female Japanese macaques engage in homosexual "consortships," temporary but lasting sexual relationships, he said. During a period of close observation on 21 homosexual consortships, he observed 3,945 female-female mounts, "they were mounting about once every two minutes," he noted.
"The 'mounter' typically pelvic thrusts against the 'mountee,'" said Vasey. They assume a range of positions identical to heterosexual equivalents, including the "jockey" or sitting mount, and the "double foot-clasp" mount, where the mounter grips onto the hind legs of the mountee.
"The [mountee] will turn around and gaze really intently into the mounter's eyes," said Vasey. They even "lip quiver at each other," he added.
Looking for an explanation, Vasey has tested frequently suggested "sociosexual" explanations for homosexual behavior, such as asserting dominance and mediating alliance formation.
"I've tested all of the major functional explanations," Vasey told BioMedNet News, "and none of them seem to hold."
Instead, he calls on "evolutionary history." Young male macaques demonstrate sexual behavior in games, said Vasey. One male will "mount prompt" another, by putting his hands on his playmates hind-quarters, but before he gets to mount, the playmate frequently "swivels around" and mounts the initiator. It's such a well-rehearsed game, said Vasey, that male macaques end up mounting whoever tries to mount them. Female macaques have apparently worked this out and frequently mount males to encourage them to mate.
Thus, natural selection favors female male mounting, said Vasey. But how has that transferred to female-female mounting?
"They're rubbing their clitorises on the males' back, they're also mastubating with their tails," he said. "So at that point in the evolutionary scenario you have a system where females have evolved the capacity to mount and that capacity is being maintained in the population by natural selection. But they have also evolved the capacity to derive sexual gratification from mounting ... and they can mount the male and derive sexual gratification just as well as they can mount the female and derive sexual gratification."
Homosexuality among female macaques, Vasey concluded, "is a by-product of selection for the adaptation of female male mounting."
Clearly, he admitted, his findings are species-specific. Nonetheless, he added, his approach "would suggest a possible avenue for future research in humans."
Joan Roughgarden, who until Spring 1998 was Jonathan Roughgarden, is not convinced. "Paul doesn't offer any data on lifetime reproductive success," she said. "He must show that the fitness of a macaque who is homosexual is very close to the fitness of a macaque who isn't homosexual."
Functions for homosexual behavior are known in dolphins, oyster catchers, mountain sheep, and others, she says. And while these do not relate directly to human homosexuality they illustrate that homosexual behavior is a "perfectly natural activity well within the scope of evolutionary theory."
"The cause of the evolution of homosexuality in humans seems rather mysterious," she added. "I feel we need much more attention to the nature of the relationships that are built between people based in part on their homosexuality."
-------
I can give a few contrarian remarks about the evolutionary framework of the article, but it's a bit irrelevent.
What do you guys think?
It just suited you perfectly somehow. It will be dearly missed.
) so I'll end this with a quote from 
