An interesting new study looks at the genetic link to homosexuality and explains why identical twins do not always have the same sexual orientation:
Long thought to have some sort of hereditary link, a group of scientists suggested Tuesday that homosexuality is linked to epi-marks—extra layers of information that control how certain genes are expressed. These epi-marks are usually, but not always, “erased” between generations. In homosexuals, these epi-marks aren’t erased—they’re passed from father-to-daughter or mother-to-son, explains William Rice, an evolutionary biologist at the University of California Santa Barbara and lead author of the study.
Another nail in the coffin of the “it’s a choice” crowd, whether religious fundamentalists on the right or queer theorists on the left.