2023-05-16 ミシガン大学
◆同性間の性行動に関連する遺伝子は、現代の社会では避妊の普及により子供の数との関連が逆転し、子孫への遺伝的維持機構が失われている可能性がある。異性愛者にとっては利益をもたらすかもしれないが、現代の社会ではその効果がなくなったため、同性間の性行動に関連する遺伝子は徐々に減少する可能性がある。
◆この研究は英国の人々を対象にしているため、他の人口集団には当てはまらない可能性がある。
<関連情報>
- https://news.umich.edu/contraception-evolution-and-the-genetic-maintenance-of-same-sex-sexual-behavior/
- https://www.pnas.org/doi/10.1073/pnas.2303418120
避妊は人間の同性間性行動の遺伝的維持に終止符を打つ Contraception ends the genetic maintenance of human same-sex sexual behavior
Siliang Song and Jianzhi Zhang
Proceedings of the National Academy of Sciences Published:May 15, 2023
DOI:https://doi.org/10.1073/pnas.2303418120
Abstract
Because human same-sex sexual behavior (SSB) is heritable and leads to fewer offspring, it is puzzling why SSB-associated alleles have not been selectively purged. Current evidence supports the antagonistic pleiotropy hypothesis that SSB-associated alleles benefit individuals exclusively performing opposite-sex sexual behavior by increasing their number of sexual partners and consequently their number of offspring. However, by analyzing the UK Biobank, here, we show that having more sexual partners no longer predicts more offspring since the availability of oral contraceptives in the 1960s and that SSB is now genetically negatively correlated with the number of offspring, suggesting a loss of SSB’s genetic maintenance in modern societies.
