A scientific team from the University of Tennessee-Knoxville, University of California, Santa Barbara, and Uppsala University in Sweden reports the completion of a research project indicating that homosexuality may be the result of epigenetic influences on sexual development. According to the study, published online today in The Quarterly Review of Biology, sex-specific epi-marks, which normally do not pass between generations and are thus “erased,” can lead to homosexuality when they escape erasure and are transmitted from father to daughter or mother to son.