In a new study, researchers have found that almost half of all people in the society carry 'gay genes' and since 'gay gene' are being carried by straight men and women, gay people will continue to born. Thus, the society will always have a gay population, regardless of whether gay people choose to reproduce.
The findings were published in journal Archives of Sexual Behavior.
Sisters of gay men tend to have more children
According to the study by Giorgi Chaladze, of Ilia State University in Tbilisi, Georgia "sisters of gay men tend to have more children, which could be why large population centers will always produce gay children". Chaladze also found that straight men carry genes that predispose them to being gay. Dr. Chaladze used a computational model to determine the influence of genes and heredity on homosexuality, including its distribution throughout both history and various cultures. “The trend of female family members of homosexual men to have more offspring can help explain the persistence of homosexuality,” Chaladze said, adding “if we also consider that those males who have such genes are not always homosexuals.”
Male homosexuality present in wider population
Chaladze’s findings, determined that male homosexuality is present in the wider population at “low and stable frequencies”, If fifty percent of men and more than fifty percent of women carry genes that produce male homosexuals. Chaladze’s main aim with the study was to determine why gay men still exist, despite straight males reproducing at a rate five times higher than their homosexual counterparts. Gay men couldn’t be exclusive carriers of any such “gay gene,” as it would have led to their extinction.
Male sexual orientation influenced by genes: Study
The US researchers had, in a previous study found evidence that male sexual orientation is influenced by genes. Scientists tested the DNA of 400 gay men and found that genes on at least two chromosomes affected whether a man was gay or straight. A region of the X chromosome called Xq28 had some impact on men's sexual behaviour – though scientists had no idea which of the many genes in the region are involved, nor how many lie elsewhere in the genome. Another stretch of DNA on chromosome 8 also played a role in male sexual orientation – though again the precise mechanism is unclear.
Genes may have survived evolution
Researchers have speculated in the past that genes linked to homosexuality in men may have survived evolution because they happened to make women who carried them more fertile. This may be the case for genes in the Xq28 region, as the X chromosome is passed down to men exclusively from their mothers. The link with the mother's side of the family led the researchers to look more closely at the X chromosome. In follow-up work, researchers found that 33 out of 40 gay brothers inherited similar genetic markers on the Xq28 region of the X chromosome, suggesting key genes resided there.