Joanna Briscoe: Hot lesbian monkey sex action - now that's what I call progress

Female primates who take to drinking from the furry cup are thought to be doing so for social reasons rather than sexual

Charles Darwin was wrong. His evolutionary tenet that the fair sex is coy, passive and slack in the sack just won't wash any more. According to research unveiled at the American Association for the Advancement of Science last week, promiscuous female macaque monkeys are often bisexual and aggressively compete with males for sexual partners, neatly challenging Darwin's theory that females just wait for the big boys to make the moves. As well as enjoying girl-on-girl action, the female macaques tend to mount sluggish males in an attempt to kick-start copulation. So much for the male as highly ornamented aggressor competing for survival of the fittest, while the dull little female simply lies back, points a paw and takes her genetic pick. And how apposite that a pack of frisky girl monkeys have turned Darwin's theories of sex selection on their head.

These findings by Dr John Vasey of the University of Lethbridge, Canada, must tinker with our assumptions about gender roles, but are they as relevant to the nightclub as the jungle? Let's take the lesbian bit first. That's the juicy part, the one that's secured the headlines at a time when the Russian pop duo Tatu's Sapphic contortions have topped the pop charts for weeks, and we're still reeling from the leather dildos in Tipping the Velvet. Japanese lesbian monkeys:this is about as cool and exotic as it gets in this minor renaissance of lesbian chic. But while lesbianism – or at least a little Sapphic sexual tourism – is culturally visible, a stock media favourite, and almost obligatory for any serious young nightclubber, how many genuine lesbians do you spot around the water cooler? Not that many. The latest national sex survey, published in The Lancet, found that 5 per cent of women have had a homosexual experience. The figure stood at only 2 per cent a decade ago.

What's changed then, is that, like the monkeys, more women are experimenting. Encouraged by a post-ladette culture in which female celebrities visit lap-dancing clubs, Sex and the City espouses the odd slice of lady love, and actresses such as Winona Ryder are photographed holding hands with their female friends, women no longer perceive Sapphism as the exclusive province of crop-heads in skinny vests or tweedy inverts.

However, those lusty macaques, happy to vie with the male for another female's attention, seem to demonstrate more authentically bisexual behaviour than we larger, less hairy apes, who may be largely doing it for show. Though essentially straight women will try the lesbian lark, the theory that says we're-all-bisexual-at-heart, the one that politically correct commentators have been banging on about for ever, seems to hold no more water today than it ever did. Again, how many genuinely bisexual people do you know? The majority of us identify with one sexuality or another.

As for the other monkey business (females leaping on males in the hopes that a bit of frottage will interest them), why is anyone so surprised? Women have always been assertive, even if traditional evolutionary theory and our culture refuse to countenance it. But a lot of that Darwinian stuff never did apply further up the food chain. Human males clearly fail to sport the peacock feather ornamentation of their animal brethren. The fornicating female macaque, however, has found the perfect human incarnation in Samantha Jones of Sex and the City. Dr Vasey said that he started out imagining that sex between female macaques must play some kind of evolutionary role, such as strengthening links between mothers in order to help raise their offspring. However, this has not been supported by his research. Again, this says a lot about our assumptions. Female primates who indulge in same-sex activities are thought to be doing so for social reasons rather than sexual. Women, the theory goes, are kinder, more understanding, more thoughtful than the sexy brute male – but what if the distaff side also turns out to be damn good sex? Darwinian hell breaks loose.

As evolutionary theories receive yet another shake-up, patriarchy may find less of a champion in biology. Macaque monkeys as emblems of liberation? The Pankhursts of our day? Who knows? We may just have found the missing link.