Религија и хомосексуалност

HOMOSEXUALITY AND GENETICS

The question remains of whether homosexuality is a choice or is it genetic. Many people argue that it is not a choice. Nobody would choose a life that is difficult and faces ridicule and discrimination. We do not know the cause of homosexuality, but scientists are starting to reveal some very interesting research that may proved that being gay can be genetically determined, or an individual my be genetically predisposed to be gay. It has been shown that among families, family members who are gay is very high. Over 60% of identical twins, if one is homosexual, the other is too. Non-identical twins, 22% are gay.

Several genetic studies have been done that appears to genetically link homosexuality. Pillard and Bailey did a study on twins and homosexuals. They compared the percentage of male siblings who were both gay with the amount of genetic material they shared in order to find evidence for a genetic link of homosexuality. Among twin pairs where one twin was gay, they found that 52% of the identical twins were both gay, 22% of the fraternal twins were both gay, 9% of the non-twin brothers were both gay, and 11% of the adopted, or genetically unrelated brothers were both gay. They concluded that because the identical twins have a higher percentage rate than other siblings, the idea that sexual orientation is genetically influenced is consistent. Some experts questioned Bailey and Pillars findings. They both agreed they had difficulty finding a random and unbiased sample of homosexual population. They also were not able to categorize bisexuality as being either homosexual or heterosexual, and did not allow for it to be its own trait. Because of this, experts felt this study could not determine homosexuality as genetic.

Another study done by Simon LeVay focused on the size of INAH3 nucleus of the hypothalamus. He wanted to test whether the areas INAH-2 and INAH3 in the nucleus were different in size not by sex, but by sexual orientation. By proving a difference in size, he could establish that the brains of gay men were similar to that of women's brains. He only found that INAH-2 exhibited difference in sexual orientation. It was two times larger in heterosexual men as homosexual men, and he concluded it was different because of sexual orientation, not because of a difference in sex.

Dean Hamer, a molecular geneticist also did a study which tried to identify genetic markers which could influence a person's sexual orientation. Hamer recruited male siblings who were both gay and created a family tree chart tracing the incidence of homosexuality among family members. He identified the X chromosome as the site for the genes that code for homosexuality. He analyzed the DNA of each pair of brothers and also analyzed the DNA of mothers, when it was available. Hamer thought that if the mother's DNA showed two sets of markets, one on each chromosome, and each of their homosexual sons shared the same kind of marker, than the sibling pair was deemed concordant-by-descent, which would allow Hamer to declare a genetic link to homosexuality. The biggest critique of this was that Hamer never actually found the homosexual gene.

In conclusion, a large amount of evidence is leading us to the genetic link towards homosexuality, but not entirely a conclusive one.