Considering that it’s happening all the time, everywhere, all across the world, there’s a lot that scientists still don’t know about the female orgasm. Although the debate over the chemistry of female ejaculation has been settled, it’s still not definitively clear how many types of female orgasms there are.
The most tantalizing question of all, though, has barely been addressed – namely, what is the evolutionary point of the female orgasm? Writing in the Journal of Experimental Zoology Part B: Molecular and Developmental Evolution, a team of scientists at Yale University thinks they’ve come up with an answer.
Rather than merely evolving as a trait to accompany the male orgasm, which some presumed was an adaptation to encourage pair-bonding between partners, these researchers have concluded that it was once the key biological trigger required for ovulation to take place.
When women orgasm, they release two hormones, oxytocin, and prolactin. In the females of wild placental mammals, this type of hormonal discharge actively causes ovulation to begin, and without it, pregnancy would not be possible. The male and female orgasms work together, so to speak, to begin ovulation.
It’s likely that the same mechanism initially evolved in human females for precisely the same reason. Over time, women developed the ability to ovulate on cycles independent of male sexual activity. This hormonal function was rendered unnecessary and it became superfluous, but it stuck around in female biology due to its secondary role as a pleasurable bonding mechanism.
“Prior studies have tended to focus on evidence from human biology and the modification of a trait, rather than its evolutionary origin,” co-author Gunter Wagner, a professor of ecology and evolutionary biology at Yale University, said in a statement.