How gay sex can lead to birth of an offspring

London, Oct 21 : Gay sex can produce offsprings, at least in the case of beetles, says a new study, which found that the 'kinky' activity gives males a chance to indirectly fertilise females they may never encounter directly.

Biologists have speculated that homosexual copulation in beetles might help males practise for straight sex, or they might offer males a way to assert dominance over one another.

In order to test these explanations, Sara Lewis, an evolutionary ecologist at Tufts University in Boston and colleagues investigated flour beetles (Tribolium castaneum)

She observed that, when housed together in laboratory containers, male beetles often mount one another and copulate, and even end up transferring sperm at times.

As it is already known, that males, being able to discriminate between virgin and mated females, cannot really mistake their male mates for females, reports New Scientist.

In fact, the researchers found that even male beetles with homosexual experience were no better than virgin males at siring offspring when allowed to copulate with a female later. This, according to the team rules out the "practise" hypothesis.

Also, the team found no since difference between the mating males and neither male had an advantage when the two were forced to compete for a single female. This rules out the "dominance" hypothesis.

However, the researchers found that male-male matings can result into an unexpected, though subtle, benefit-some of the sperm transferred during such encounters may later be "accidentally" passed along when the recipient male later mates with a female.

It was revealed that only 6 of 84 (7pct) male-male copulations resulted in second-hand fertilisations, and less than 1pct of offspring were indirectly fathered.

However, Lewis said that this is the first report of indirect sperm transfer from homosexual matings.

She believes that homosexual matings may offer males a way to move young, vigorous sperm to the front after dumping older sperm that are past their best-before date.

However, Paul Vasey, an evolutionary biologist at the University of Lethbridge, Canada, who studies homosexual behaviour in monkeys, has said that none of Lewis's proposed adaptive benefits to homosexual copulation is very strong,

However, he suggested that the beetles' homosexual mating may not be adaptive at all, and could instead be a byproduct of some other behaviour that is adaptive, such as a general readiness to mate.

ANI