Daily Loaf

Homosexuality has long been difficult to explain in terms of natural selection, as homosexuals reproduce at a lower frequency than their heterosexual counterparts. This would seemingly doom genes related to homosexuality to extinction. However, the fact that homosexuality exists in such a large variety of species suggests that it in some way offers an evolutionary advantage. Otherwise, genes that code for homosexuality would die off (off course this presupposes that you believe homosexuality is determined by nature as opposed to nurture). While homosexuality may not be entirely hereditary, evidence strongly suggests it is largely determined by genetics. Proof of this is the high rate of homosexuality in identical twins, at least for males.

A recent study by Camperio Ciani finally discovered the genetic advantage of genes related to homosexuality in males. Ciani demonstrated that women in a maternal line of homosexual men are on average more fertile than females who aren’t related to male homosexuals. As a result, these women pass on genetic material linked to homosexuality in males and hyper-fertility in females at higher rates.

This is an example of sexually antagonistic selection, which is a type of selection that gives a reproductive advantage to one sex while disadvantaging the other. Consequently, the genes related to homosexuality are not detrimental in terms of fertility, as they give a reproductive advantage to female carries. As of yet, homosexuality is the first example of sexually antagonistic selection in humans, but others are sure to be found.

Read more at Scientificblogging.com and read Camperio Ciani’s study at PloS One

Follow Alfie on Twitter or Facebook

Posted in LGBT, Sex and Love | Leave a comment