Innate orientation

They don't become gay
The results of the study confirmed,
that a person's sexual orientation is determined by his genomeMikhail Karpov, "Russian Planet"

DNA analysis of 409 pairs of homosexual brothers allowed us to obtain a weighty confirmation of the hypothesis that homosexuality is an innate feature of a person. The authors of the work published in the journal Psychological Medicine (Sanders et al., Genome-wide scan demonstrates significant linkage for male sexual orientation), associate the sexual orientation of men with the configuration of two regions of the human genome: the eighth chromosome and the X chromosome. The region of the X chromosome that became the subject of the study was discovered by Dean Hamer of the US National Institutes of Health in 1993. Another region, located in the center of the eighth chromosome, was found by an international team of scientists in 2005.

Over five years, Sanders and his colleagues collected blood and saliva tests from 409 pairs of homosexual brothers who are not identical twins from 384 families. Most of the subjects lived in the USA (98.2%). Canadians (1.6%) and Britons (0.2%) also participated in the study. Scientists specially selected close relatives, since, according to surveys, members of families in which there are homosexuals themselves are much more likely to define themselves as homosexuals, unlike families whose members are all heterosexuals.

Scientists were looking for single-nucleotide polymorphism in the DNA of the subjects, differences in the sequence size of one nucleotide ("letter") in the genome. Then they found out what features are present in the DNA of volunteers relative to the DNA of heterosexual people. Since the brothers were not identical twins, their genomes differed from each other, and they themselves were often little alike. Thus, the researchers took it for granted that a certain repeating region of DNA would be responsible for a person's sexual orientation.

The authors of the work identified only five suitable cases of single-nucleotide polymorphism, and all of them were in the regions of the genome Xq28 and 8q12 (chromosome X and the eighth chromosome). However, one should not assume that scientists have already found some "homosexuality genes". There are many genes in both regions, and the next stage of the work will be to determine which of them affect a person's sexual orientation.

Whatever the results of this study, scientists emphasize that such a complex feature of behavior as sexual orientation depends on many factors, both external and genetic. Even the detection of specific genes will not make such a big difference – as, for example, in studies studying human mental abilities.

Other scientists investigating human sexual orientation were enthusiastic about Sanders' work. According to neuroscientist Simon Levy, who claimed that a certain part of the brain in the hypothalamus region of gays is smaller, this study "hammers a new nail into the coffin of the idea that homosexuality is a conscious choice." Dean Hamer was also encouraged by the result. According to him, "twenty years is a long time, but now it is clear that the initial results (of the Hamer–RP study) were correct."

The possible mechanism of transmission of the "homosexuality gene" was described by William Rice from the University of California at Santa Barbara, and mathematically proved its reality by the scientific director of the National Institute of Mathematical and Biological Synthesis at the University of Tennessee in the USA Sergey Gavrilets. According to Rice's theory, children can receive certain epigenetic "marks" from parents of the opposite sex, which determine the direction of their sexual desire in the future.

In many countries, homosexuality is still criminalized (for example, in the Gambia, they can be imprisoned for 14 years for non-standard sexual orientation). Some religious groups and psychologists are still convinced that this feature of human behavior is a mental deviation, and it can and should be treated.

Portal "Eternal youth" http://vechnayamolodost.ru19.11.2014