According to this article (http://www.eurekalert.org/pub_releases/2012-12/nifm-sfe120612.php http://www.eurekalert.org/pub_releases/2012-12/nifm-sfe12061...) ho

According to this article (http://www.eurekalert.org/pub_releases/2012-12/nifm-sfe120612.php http://www.eurekalert.org/pub_releases/2012-12/nifm-sfe12061...) homosexuality is epigenetic and not genetic (i.e. is not related to a specific gene, but to chemical differences that affect the expression of genes).