Scientists reveal what drives homosexual behaviour in primates

HOMOSEXUAL behaviour in primates has a deep evolutionary basis and is more likely to occur in species that live in harsh environments, are hunted by predators or live in more complex societies, scientists said this week.

- BENEDICTE SALVETAT REY (AFP)

Males or females of the same sex mounting or otherwise stimulating each other have been documented across the animal kingdom.

More than 1,500 different species have been observed engaging in same-sex sexual behaviour, with some of the earliest reports dating back to the ancient Greek philosopher Aristotle.

But this relatively common behaviour was long dismissed by the scientific community as a "Darwinian paradox". This held that homosexual behaviour in animals goes against Charles Darwin's theory of evolution because it does not pass down genes through reproduction.

More recently, scientists have shown that this behaviour can in part be inherited from an animal's parents -- and can provide an evolutionary advantage.

"Diversity of sexual behaviour is very common in nature, among species and in animal societies -- it is as important as caring for offspring, fighting off predators or foraging for food," Imperial College London biologist Vincent Savolainen told AFP.