It is surprising that sexual behavior between individuals of the same sex has been observed in more than 1,500 animal species, covering a wide range of taxonomic groups. These species range from invertebrates, such as insects, spiders, echinoderms, and nematodes, to vertebrates, such as fish, amphibians, reptiles, birds, and mammals. It is a phenomenon that challenges conventional explanations of reproduction and raises important questions about its function and evolution in the natural world.
Perhaps that is why it has attracted the attention of various academic disciplines, including zoology and evolutionary biology. Same-sex sexual behavior is defined as any momentary behavior, usually performed by a member of the opposite sex, but directed at individuals of the same sex. Although not directly contributing to reproduction, this type of sexual behavior represents a mystery from an evolutionary perspective.
Our research team investigated the evolution of sexual behavior between individuals of the same sex in mammals in a study recently published in the journal Communication in Nature.
It is currently recorded in approximately 5% of species and 50% of families, and is practiced with similar prevalence in men and women.
Sexual behavior between individuals of the same sex appears to be a common tendency among mammals. It is currently recorded in approximately 5% of species and 50% of families and is practiced with similar prevalence in men and women.
According to the available data, this behavior is not randomly distributed among mammalian lineages but is more widespread in some groups, especially monkeys, where it has been observed in at least 51 species, from lemurs to monkeys.
In some species, this behavior is rare and will manifest itself under certain circumstances. However, in 40% of species, homosexual behavior is a moderate or frequent activity during mating.
These findings raise interesting questions about the biology and evolution of sexuality in the animal kingdom.
A way to strengthen social relationships
Our study made an interesting discovery by revealing important links between the same-sex sexual behavior of mammals and their patterns of social behavior.
Our analysis confirms that the species that show more developed social behaviors, both in males and females, have a greater probability of showing these interactions between individuals of the same sex. These results support the hypothesis that this sexual behavior is favored by evolution as a way to build, maintain, and strengthen social relationships that increase relationships and alliances between members of the same group.
Our analysis confirmed that the species that show more developed social behaviors, both in males and females, have a greater probability of showing these interactions between individuals of the same sex.
This comparison of phylogenetic analysis also found a relationship between this sexual behavior and intrasexual violence between individuals of the same sex, but only in the case of men. Species whose males are more violent are more likely to exhibit this sexual behavior at some point in their lives.
The study therefore suggests that the same-sex sexual behavior exhibited by non-human mammals is an adaptation that plays an important role in maintaining same-sex social relations and mitigating conflicts primarily between the sexes.
Be careful when extrapolating.
In any case, we emphasize the need for caution because these associations may be due to other factors. In addition, the results exclude other hypotheses about the evolution of sexual behavior between individuals of the same sex, which require further investigation.
It is also important to note that the results should not be used to explain the evolution of people’s sexual orientation. This is because the study focuses on sexual behavior between individuals of the same sex, defined as short-term courtship or mating interactions, rather than a more permanent sexual preference.
Finally, we must remember that sexual behavior has only been carefully studied in a minority of mammals. This means that our understanding of the evolution of same-sex sexual behavior in mammals may change as more species are investigated in the future.