What’s the point of the female orgasm? Sure, it’s fun and all, but scientists didn't understand its evolutionary purpose. A team of evolutionary biologists from Yale University have now provided a fresh look at the purpose of the elusive female orgam, and suggest the hormone rush associated with an orgasm first arose as a way to stimulate ovulation in female mammals at a time before women evolved menstrual cycles.

According to this new theory, before mammals evolved ovarian cycles, the female orgasm stimulated ovulation through the release of the hormones prolactin and oxytocin. During this point in evolutionary history, the clitoris was also located in the vagina, which made stiumlating the clitoris easier, and better assured an orgasm during sex. Once mammals evolved cycles, they no longer needed sex to stimulate ovulation, and the clitoris moved out from the vagina to reflect this shift.

The team studied the anatomy of female mammals that still relied on intercourse to stimulate ovulation, and showed for the first time that male-induced ovulation came first, and spontaneous ovulation, such as what human females have, came later. While the male orgasm is obviously required for fertilization and reproduction, the female orgasm is not, which is why some think the female orgasm is a by-product of evolution, such as the male nipple. However, other biologists aren’t so quick to write-off the female orgasm as completely useless, outside of pleasure.

Other popular theories suggest that an orgasm is a biological reward for women, and helps to encourage them to have more intercouse and thus up their chances for reproduction, Popular Science reported. Another theory suggests the vaginal contractions which occur during the point of orgasm help to “suck up” the sperm into the vagina, increasing the chances of fertilization. Yet another popular theory suggests that the female orgasm is not designed to ensure fertilization, but rather that hormones released during orgasm encourage females to bond with their male partners, thus increasing the chances of co-parenting for their offspring.

Source: Wagner G, Pavličev M. The Evolutionary Origin of Female Orgasm. JEZ-Molecular and Developmental Evolution. 2016