The preference of men for younger female partners could have led to menopausal women in the course of evolution. This is what Canadian scientists now want to have found out from new computer simulations. Thus, competition among men of all ages for young female partners has resulted in older women having a much lower chance of reproducing. It may be that they were able to assert mutations that reduce fertility – and that may have led to the emergence of menopause over time. Menopause, ie the time of the last menstruation, marks the end of fertility in the woman. By the way: that women continue to live after their reproductive phase of life (!), Is a feature that exists almost exclusively in humans. Only whales and captive chimpanzees are aware of this, according to research published by researcher Rama Singh of McMaster University . Menopause: From the Granny Hypothesis to Men's Guilt According to the researchers, there are already several theories for why menopause occurs in humans – but none of these explanations are satisfactory. One of the prevailing theories is the "grandmother hypothesis ". Thus, older women become infertile so they can help raise their grandchildren. This is supposed to strengthen their overall fitness, ie the transmission of their own genome. In developing the new menopause theory, Rama Singh and his colleagues performed various computer simulations with a model population of equal numbers of men and women. In their model, they considered different genomic mutations independently of each other: gender-independent mutations that increase mortality, and gender-dependent mutations that cause decreased fertility. In addition, it was included in the model that mate choice influences fertility. If the men in the model preferred younger female partners, then the female-specific infertile mutations accumulated in the population. As a result, women's fertility declined even before they reached the end of their lives – the menopause occurred. In the opposite case, men would have lost their fertility evolutionist Singh points out that the development could have been the other way around as well: if women had been the ones to choose younger partners in the past, men would have lost their fertility in old age. Menopause usually occurs around the age of 50 years. Menopause is the period before and after the menopause. During this phase of life, the hormone balance of the woman is reversed: for example, the estrogen level drops drastically. During menopause, women may experience hot flushes, sweats and mood swings. In addition, the risk of the bone disease osteoporosis increases due to the hormonal change.