Homosexuality presents an intriguing paradox for evolutionary biology. If homosexual individuals, on average, have fewer offspring than heterosexual people, and sexual orientation is at least partly genetically determined, how can genetic predispositions for homosexuality persist in the human population? A recent study by Jakub Fořt and his colleagues from the Human Ethology group at the Faculty of Science, Charles University, aimed to answer this question.
The online questionnaire study, published in the journal Evolution and Human Behavior, focused on assessing the fertility of participants' relatives. The study included approximately two thousand homosexual and heterosexual men and women.
A popular science summary of the study in English is available on the blog of the Human Behavior & Evolution Society.