It's a question that has stumped the greatest scientific minds throughout history: Why do women have orgasms?
For men, the explanation is obvious. The euphoric sensation is necessary to release sperm, which then fertilizes a woman's egg. But for women, having an orgasm is not needed for reproduction, leaving scientists — and other curious types — to ponder what greater biological purpose, if any, it serves.
Now researchers from Yale University and the Cincinnati Children's Hospital suggest the answer can be found by delving into the past. In early mammals, the female orgasm was a reflex occurring during sex that caused the release of an egg.
Over time, they say, some female mammals evolved to ovulate spontaneously every month. Others, such as rabbits and cats, still rely on orgasms to induce ovulation.
Yet in all females, there is a surge of hormones released in the process.
The researchers published their findings earlier this week in the Journal of Experimental Zoology-Molecular and Developmental Evolution.
"Prior studies have tended to focus on evidence from human biology and the modification of a trait rather than its evolutionary origin," Gunter Wagner, an ecology and evolutionary biology professor at Yale University, said in a news release.
The fact that human females often experience orgasms "unreliably" during sexual intercourse also contributes to the idea that its function is not reproductive, the researchers noted in their study.
