Study says nearly every species of animal engages in homosexual behavior

June 16, 2009

According to a recent study, almost every kind of animal on engages in same-sex sexual behavior whether intentional or natural. Lead scientist on the study, Nathan Bailey, says the list includes, among others,, penguins, frogs and.

"It's clear that same-sex sexual behavior extends far beyond the well-known examples that dominate both the scientific and popular literature," said Bailey, a postdoctoral researcher of biology at.

The study was published in today's edition of the journal .

In some cases the animals are not aware that they are engaging in same-sex sexual behaviors. One example are male. According to the study, males in some cases will unintentionally cater to other male flies because they lack a gene which allows them to determine the sexes of other fruit flies. have also been known to sometimes engage in same-sex sexual behavior as a way to socially bond with other dolphins.

Bailey states that such actions will have an effect on, but that science is only just beginning to research what the effects might be. Bailey also said that natural selection could be playing a role in what animals engage in same-sex sexual behavior.

"Like any other behavior that doesn't lead directly to reproduction — such as aggression or — same-sex behavior can have evolutionary consequences that are just now beginning to be considered," Bailey said.

He added that "same-sex behaviors —, mounting or parenting — are traits that may have been shaped by natural selection, a basic mechanism of evolution that occurs over successive generations."

Scientists included in the study research on the origins of homosexual behavior in animals, examining whether the behavior is adaptive in an animal's environment, and whether it happens often.