Men cause premature menopause

Men may have caused menopause by liking younger partners

14/06/2013

By choosing younger partners, men may have favored the menopause of older women. That resulted in a computer simulation of Canadian scientists. Accordingly, the preference of younger companions has meant that older women had fewer and fewer opportunities to reproduce. According to the researchers, this has over time favored the development of mutations that reduce fertility.

Preference of men for younger women is said to have favored mutations for menopause
Both the origin and the development of the menopause, ie the time of the last menstruation of the woman, are well-kept secrets so far. Although scientists have come up with different theories for the development of infertility in older women, there has been no satisfactory explanation for the phenomenon. Some scientists assume that older women become infertile to help raise the grandchildren. This should strengthen their overall fitness and thus the transmission of their own genetic material.

According to the Canadian researchers, however, their findings invalidate many of the theories. „Our model shows for the first time that neither the assumption of pre-existing reduced fertility in older women, nor the benefits of giving older, infertile women the support of young women in raising children, are necessary to explain the origin of the menopause“, the researchers write.

Computer simulation explains the origin of the menopause
Richard A. Morton, Jonathan R. Stone, and Rama S. Singh of the Department of Biology at McMaster University, Hamilton, Canada developed a computer simulation model that established a link between favoring younger female partners and older women's menopause. „We developed and used a computational model and a computer simulation to show that the preference for younger women in male mating behavior could have led to the accumulation of mutations that are harmful to female fertility, causing menopause“, the researchers write in the journal „PLOS Computational Biology. "Due to the preference of younger women, older women would have fewer and fewer opportunities to reproduce and, over time, the mutations that led to infertility would have developed.

The computer simulation showed that more and more female-specific infertility mutations occurred when men preferred younger women. As a result, the fertility of women declined and menopause occurred. As the researchers report, the development could have been different: "If the women had preferred younger men, the men would have become infertile in old age".

Almost all living beings except humans die after the menopause
Menopause usually occurs in women around the age of 50 when the woman reaches menopause. It marks the time of the last spontaneous menstruation. Due to the conversion of the hormone balance, for example, the estrogen level drops significantly during this time.

In the animal kingdom, the occurrence of infertility means death in almost all animals. Only humans, whales and captive chimpanzees continued to live after their reproductive phase, the researchers report. (Ag)