Bisexuality: Genetic variations may provide reproductive advantages

In today's society, the diversity of sexual orientation has been more and more widely accepted and discussed. Among them, bisexuality as a sexual orientation has been controversial and misunderstood for a long time. However, a recent study may bring a new perspective to our understanding of bisexuality. Professor Jianzhi "George" Zhang and his team at the University of Michigan conducted a study to examine the possible reproductive implications of genetic variation behind bisexual behavior (BSB).

The background of this study is based on a long-standing Darwinian paradox: if same-sex sexual behavior (SSB) leads to fewer offspring, why do SSB-related alleles persist in the population? To address this question, the team proposed the hypothesis that SSB-related alleles may provide a reproductive advantage in heterosexuals.

Prof. Chang's study found that bisexuality (BSB) is positively associated with more children genetically, although the number of sexual partners no longer predicts the number of offspring due to the widespread use of contraception in modern British society. This suggests that BSB-associated alleles may promote heterosexual reproduction. The team further explored the trait of adventurous behavior and found that it was positively associated genetically with BSB and the number of children. These results suggest that adventurous behavior may be the underlying cause of BSB-related alleles promoting heterosexual reproduction.

It is worth noting that this study also observed that BSB was genetically associated with more children, but this does not mean that BSB was actively selected for. Because SSB is also associated with increased mortality, the reproductive advantage and viability disadvantage of the BSB-associated allele would likely cancel each other out, and thus BSB could be genetically maintained.

The results of this study provide us with a new perspective to help us understand the possible evolutionary role and significance of bisexuality. It emphasizes the complexity of the genetic and evolutionary mechanisms behind sexual orientation and suggests the need for a more open and pluralistic perspective when discussing sexual orientation.

However, Prof. Cheung also pointed out that the empirical analysis of this study relied on the European-heritage UK Biobank participants, and thus the applicability of its findings to other ethnic groups is still subject to further research. Future studies will need to explore the genetic and evolutionary mechanisms behind sexual orientation in different cultural and social contexts to gain a more comprehensive understanding.

This study not only provides us with a new understanding of bisexuality, but also opens up new avenues for future exploration in the field of sexual orientation research. As science advances, we look forward to unraveling more of the secrets of sexual diversity in the future.