Evolutionary scientists have been thinking about same-sex sexual behavior all wrong.
That’s the implication of a new study on same-sex behavior in animals. Instead of asking why animals engage in same-sex behavior (SSB), researchers should be asking, “Why not?” the authors said.
If they’re right, same-sex sex may not have evolved independently in different animals for adpative reasons. Instead, same-sex sex may have emerged very early in time and could persist simply because engaging in it doesn’t cost animals much, evolutionarily speaking.
“Usually, when evolutionary biologists see a trait that’s really widespread across evolutionary lineages, we at least consider the idea that the trait is ancestral and was preserved in all those lineages,” said Julia Monk, a doctoral candidate at Yale University, who co-authored the new research. “So why hadn’t people considered that hypothesis for SSB?”