Brendan Zietsch receives funding from the Australian Research Council. He is senior author on the paper discussed. What has been elusive is knowledge of what specific gene, or genes, are involved. But a later study did not replicate this finding, and subsequent follow-ups yielded mixed results. Read more: Born this way?
The 'gay gene' is back on the scene
Differences in Male and Female Chromosomes | Sciencing
No individual gene alone makes a person gay, lesbian or bisexual ; instead, thousands of genes likely influence sexual orientation, a massive new study of the genomes of nearly half a million people suggests. The biological factors that contribute to sexual orientation are largely unknown, but many scientists suspect that genetics plays a role, given that same-sex sexual behavior appears to run in families and is seen more often in identical twins than in fraternal twins. Same-sex orientation remains criminalized in more than 70 countries, some with the death penalty, often stifling those willing to disclose such personal information. The new study, however, included a much larger number of participants, making the results more statistically reliable than those of the previous, smaller studies.
What do the new ‘gay genes’ tell us about sexual orientation?
Ushering the politically explosive study of the origins of sexual orientation into a new and perhaps more scientifically rigorous phase, researchers report that they have linked male homosexuality to a small region of one human chromosome. The results have yet to be confirmed by other laboratories, and the chromosomal region implicated, if it holds up under further scrutiny, is almost surely just a single chapter in the intricate story of sexual orientation and behavior. Nevertheless, scientists said the work suggests that one or several genes located on the bottom half of the sausage-shaped X chromosome may play a role in predisposing some men toward homosexuality. The researchers have begun a similar study looking at the chromosomes of lesbians.
The relationship between biology and sexual orientation is a subject of research. While scientists do not know the exact cause of sexual orientation , they theorize that it is caused by a complex interplay of genetic , hormonal , and environmental influences. Biological theories for explaining the causes of sexual orientation are favored by scientists.