Cause of homosexuality found: Does it matter?
Researchers say they may have pinpointed the cause of homosexuality that isn’t exactly in the genes, but nevertheless, inherited.
Scientists cite epigenetic changes in genes that persist rather than being erased as normal for the most likely reason for being gay.
According to the finding that is published in The Quarterly Review of Biology, homosexuality is known to run in families, but researchers haven’t found a so-called gay gene.
To come up with a possible explanation, researchers developed a mathematical model that combines evolutionary theory with recent information about how genes are expressed (epigenetics) related to androgen-dependent sexual development in the womb.
The scientists concluded the most ‘plausible’ explanation about the cause of homosexuality is that ‘epi-marks’ that attach to genes can change the way genes are expressed.
The researchers explain epi-marks on genes develop in the womb and are responsible for sex specific traits. Some affect the genitals; others affect sexual preference or sexual identity.
Normally epi-marks go away each generation – but if they don’t, they can be passed on in families, becoming reversed in the womb and passed from father to daughter and mother to son.
The conclusion from the study is that “sexually antagonistic” epi-marks can be passed through generations resulting in homosexuality that is “easily spread in the population”.
"Transmission of sexually antagonistic epi-marks between generations is the most plausible evolutionary mechanism of the phenomenon of human homosexuality," said the study's co-author Sergey Gavrilets, NIMBioS' associate director for scientific activities and a professor at the University of Tennessee-Knoxville in a press release.
The epigenetic cause of homosexuality found in the study is based on mathematical modeling and recent evidence that epi-marks, which are temporary and usually produced anew each generation, can sometimes escape erasure and be inherited. To prove the theory, researchers would need to test parents and their offspring.
The finding, if verified, might raise questions. Are there practical applications related to the study? Can science intervene somehow to ensure ‘natural selection’ processes don’t go awry? – Specifically, what the Catholic catechism refers to as losing the ‘gift of life’.
It’s unlikely that epi-markers for homosexuality would persist to the point that humans would no longer have a desire to procreate. The epigenetic markers that are suggested as a cause for homosexuality are undoubtedly strong.
The Catholic Church views homosexuality as a ‘trial’, stating “Every sign of unjust discrimination in their regard should be avoided”, though they do not approve of sex between same gender partners.
The study is the first to find a potential cause for homosexuality – whether or not it has any practical applications remains to be seen. The finding may matter when it comes to acceptance and understanding that being gay doesn’t require a ‘cure’.
Rice WR, Friberg U, Gavrilets S.
" Homosexuality as a consequence of epigenetically canalized sexual development"
The Quarterly Review of Biology
December 11, 2012.
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