Study Suggests that Men Caused Menopause
The phenomenon of menopause, the time in which a woman stops menstruating and is no longer capable of reproducing, has been the subject of several studies. Researchers do not know exactly why and how menopause developed but they have attempted to study it since menopause is such a unique feature in human females' lives. No other animals on this planet go through menopause. The latest theory of how menopause developed places the blame on men. According to this study, men's desire for younger women led to the development of menopause in older women.
"This paper is saying that men have played the major or dominant part in choosing mates," said biologist Rama Singh, who is a professor of population genetics and evolution at McMaster University in Canada. "Somewhere along the line in our evolutionary history, males did not mate randomly but preferred young women because they are more attractive."
The researchers, composed of Singh and his colleagues, Jonathan Stone and Richard Morton used computer models that they designed and concluded that as time passed, men's interest in younger women eventually led to menopause. The researchers stated that menopause did not occur because women needed to stop reproducing, but rather that menopause occurred because older women no longer were needed to reproduce. Since older women no longer had mates, there was no point for menstruation and thus, natural selection led to menopause.
The researchers believe that if women were the more selective mate, the reverse, in which men became infertile with age, would occur. This theory, as farfetched as it might sound, joins at least 10 other theories about menopause. One popular theory is the "Grandmother theory," in which researchers reasoned that older women evolved to be infertile so that they would have more time to rear grandchildren and keep the family genetic line going.
The study was published in PLoS Computational Biology.