Bill Sullivan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment. In the U. Despite these numbers, many people still consider homosexual behavior to be an anomalous choice. However, biologists have documented homosexual behavior in more than species , arguing that same-sex behavior is not an unnatural choice, and may in fact play a vital role within populations.
No 'gay gene', but study finds genetic links to sexual behavior
Born this way? An evolutionary view of 'gay genes'
While female sexuality appears to be more fluid, research suggests that male gayness is an inborn, unalterable, strongly genetically influenced trait. But considering that the trait discourages the type of sex that leads to procreation — that is, sex with women — and would therefore seem to thwart its own chances of being genetically passed on to the next generation, why are there gay men at all? This longstanding question is finally being answered by new and ongoing research. For several years, studies led by Andrea Camperio Ciani at the University of Padova in Italy and others have found that mothers and maternal aunts of gay men tend to have significantly more offspring than the maternal relatives of straight men. The results show strong support for the "balancing selection hypothesis," which is fast becoming the accepted theory of the genetic basis of male homosexuality.
Genes linked to being gay may help straight people get more sex
Last Updated: March 2, References. To create this article, people, some anonymous, worked to edit and improve it over time. There are 22 references cited in this article, which can be found at the bottom of the page.
By Andy Coghlan. We have known for decades that sexual orientation is partly heritable in men, thanks to studies of families in which some people are straight and some people are gay. Both findings were confirmed in a study of gay and straight brothers in