The female orgasm is considered by many to be a mysterious occurrence beyond their comprehension, but science now has some answers as to why women orgasm in the first place. As is probably to be expected, it has a little something to do with reproduction. 

In a new study published in the Journal of Experimental Zoology Part B Molecular and Developmental Evolution, researchers from Yale University and the Cincinnati Children's Hospital have determined that at one point in time, the female orgasm served an evolutionary purpose in some species. Gunter Wagner, who is the Allison Richard Professor of Ecology and Evolutionary Biology at Yale and Mihaela Pavličev with Cincinnati Children's Hospital Center for Prevention of Preterm Birth found in their research that the underlying mechanism behind the female orgasm stimulates ovulation in some mammals.

There is no direct relation between human female orgasm and fertility or reproduction, but Wagner and Pavličev found that ancestrally, many mammals shared the trait of a hormone surge that would stimulate ovulation in females, an activity that the researchers say is the evolutionary predecessor of contemporary female orgasm in humans. 

The study found that over time, the orgasmic "reflex" that stimulated ovulation became unnecessary for reproduction, but the orgasm stuck around in a role that became secondary for reproductive purposes. In fact, Wagner and Pavličev's research showed that the clitoris shifted from being inside female reproductive organs to outside, where it was less easily directly stimulated during reproductive sex. 

While the female orgasm may no longer serve an evolutionary purpose in humans, there's no questioning that many still feel it's the best part of sex.