Female Orgasm: New Theory on its Origin & Function

Note: Any women care to post of what they feel the most valuable function of orgasm?

Scientists Ponder an Evolutionary Mystery: The Female Orgasm

Evolutionary biologists offered a new way of thinking about the female orgasm based on a reconstruction of its ancient history.

An eye is for seeing, a nose is for smelling. Many aspects of the human body have obvious purposes.

But some defy easy explanation. For biologists, few phenomena are as mysterious as the female orgasm.

While orgasms have an important role in a woman’s intimate relationships, the evolutionary roots of the experience — a combination of muscle contractions, hormone release, and intense pleasure — have been difficult to uncover.

For decades, researchers have put forward theories, but none are widely accepted. Now two evolutionary biologists have joined the fray, offering a new way of thinking about the female orgasm based on a reconstruction of its ancient history.

On Monday, in The Journal of Experimental Zoology, the authors conclude that the response originated in mammals more than 150 million years ago as a way to release eggs to be fertilized after sex.

Until now, few scientists have investigated the biology of distantly related animals for clues to the mystery.

“For orgasms, we kept it reserved for humans and primates,” said Mihaela Pavlicev, an evolutionary biologist at University of Cincinnati College of Medicine and an author of the new paper. “We didn’t look to other species to dig deeper and look for the origin.”

The male orgasm has never caused much of a stir among evolutionary biologists. The pleasure is precisely linked to ejaculation, the most important step in passing on a male’s genes to the next generation. That pleasure encourages men to deliver more sperm, which is evolutionarily advantageous.

For women, the evolutionary path is harder to figure out. The muscle contractions that occur during an orgasm are not essential for a woman to become pregnant. And while most men can experience an orgasm during sex, it’s less reliable for women.

In a 2010 survey, 35.6 percent of women said that they hadn’t had an orgasm the most recent time they had sex. Part of the reason for this is anatomy: the clitoris is physically separated from the vagina.

Still, a number of scientists suspect that the female orgasm serves some biological function favored by natural selection. They just need to figure out what it is.

“My gut instinct is that something that matters so much at an emotional level — the intense pleasure of orgasm — would seem to have reproductive consequences,” said David A. Puts, an evolutionary anthropologist at Pennsylvania State University.

Many hypotheses have been put forward. Dr. Puts and his colleagues have carried out studies to test the possibility that orgasms increase the odds that a woman’s eggs are fertilized by a genetically attractive male.

Elisabeth A. Lloyd, a philosopher at Indiana University, isn’t buying it. In 2005, she published a book called “The Case of the Female Orgasm,” in which she reviewed 18 published theories about its function.

None had strong evidence in its favor, she concluded, and many were undermined by other findings about human sexuality. Years of further research have only strengthened her skepticism.

Dr. Lloyd thinks the best explanation for the female orgasm is that it hasn’t served any evolutionary purpose at all. It’s nothing more than the byproduct of the development of the male orgasm. The orgasm is to women, she believes, as nipples are to men.

But now Dr. Pavlicev and her colleague, Günter P. Wagner of Yale University, are making the case that the human female orgasm has a deep evolutionary history that reaches back to early mammals.

They began by getting better acquainted with the sex lives of other animals, poring through obscure old journals to gather information on species ranging from aardvarks to koalas.

Scientists Ponder an Evolutionary Mystery: The Female Orgasm

Evolutionary biologists offered a new way of thinking about the female orgasm based on a reconstruction of its ancient history.

An eye is for seeing, a nose is for smelling. Many aspects of the human body have obvious purposes.

But some defy easy explanation. For biologists, few phenomena are as mysterious as the female orgasm.

While orgasms have an important role in a woman’s intimate relationships, the evolutionary roots of the experience — a combination of muscle contractions, hormone release, and intense pleasure — have been difficult to uncover.

For decades, researchers have put forward theories, but none are widely accepted. Now two evolutionary biologists have joined the fray, offering a new way of thinking about the female orgasm based on a reconstruction of its ancient history.

On Monday, in The Journal of Experimental Zoology, the authors conclude that the response originated in mammals more than 150 million years ago as a way to release eggs to be fertilized after sex.

Until now, few scientists have investigated the biology of distantly related animals for clues to the mystery.

“For orgasms, we kept it reserved for humans and primates,” said Mihaela Pavlicev, an evolutionary biologist at University of Cincinnati College of Medicine and an author of the new paper. “We didn’t look to other species to dig deeper and look for the origin.”

The male orgasm has never caused much of a stir among evolutionary biologists. The pleasure is precisely linked to ejaculation, the most important step in passing on a male’s genes to the next generation. That pleasure encourages men to deliver more sperm, which is evolutionarily advantageous.

For women, the evolutionary path is harder to figure out. The muscle contractions that occur during an orgasm are not essential for a woman to become pregnant. And while most men can experience an orgasm during sex, it’s less reliable for women.

In a 2010 survey, 35.6 percent of women said that they hadn’t had an orgasm the most recent time they had sex. Part of the reason for this is anatomy: the clitoris is physically separated from the vagina.

Still, a number of scientists suspect that the female orgasm serves some biological function favored by natural selection. They just need to figure out what it is.

“My gut instinct is that something that matters so much at an emotional level — the intense pleasure of orgasm — would seem to have reproductive consequences,” said David A. Puts, an evolutionary anthropologist at Pennsylvania State University.

Many hypotheses have been put forward. Dr. Puts and his colleagues have carried out studies to test the possibility that orgasms increase the odds that a woman’s eggs are fertilized by a genetically attractive male.

Elisabeth A. Lloyd, a philosopher at Indiana University, isn’t buying it. In 2005, she published a book called “The Case of the Female Orgasm,” in which she reviewed 18 published theories about its function.

None had strong evidence in its favor, she concluded, and many were undermined by other findings about human sexuality. Years of further research have only strengthened her skepticism.

Dr. Lloyd thinks the best explanation for the female orgasm is that it hasn’t served any evolutionary purpose at all. It’s nothing more than the byproduct of the development of the male orgasm. The orgasm is to women, she believes, as nipples are to men.

But now Dr. Pavlicev and her colleague, Günter P. Wagner of Yale University, are making the case that the human female orgasm has a deep evolutionary history that reaches back to early mammals.

They began by getting better acquainted with the sex lives of other animals, poring through obscure old journals to gather information on species ranging from aardvarks to koalas.