"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 University of California, Riverside.

The study was published in today's edition of the journal Trends in Ecology and Evolution.

In some cases the animals are not aware that they are engaging in same-sex tendencies. One example are male fruit flies. 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. Bottle nose dolphins have also been known to sometimes engage in homosexual behavior as a way to socially bond with other dolphins.

Bailey states that such actions will have an effect on evolution, 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 homosexual behavior.

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

He added that "same-sex behaviors — courtship, 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.

Information from: Wikinews, http://www.wikinews.org