Led by biologist Rama Singh, a team of researchers from McMaster University in Canada has discovered what may be the reason behind menopause in women - men's tendency to get attracted to younger women.

Rama Singh, who is also an evolutionary geneticist, claims that menopause is actually nothing but an outcome of natural selection, which is simply evolution's way of recognizing that older women do not possess child-bearing capacities.

"In a sense it is like aging, but it is different because it is an all-or-nothing process that has been accelerated because of preferential mating," Singh said.

The researcher speculate that the onset of menopause in women may be due to the fact that men, since a long time, have preffered younger women, which eventually led to a lack of reproduction in older women.

Singh further shuns all the previous 'grandmother' theories that claim that menopause may have something to do with the evolution of women, which hampers their reproductive cycle after a specific age. "How do you evolve infertility? It is contrary to the whole notion of natural selection. Natural selection selects for fertility, for reproduction -- not for stopping it," he claimed.

Following this study, Singh is now researching different ways to enhance and prolong women's fertility. If men hadn't shown a partial preference for younger women, menopause probably wouldn't exist, he added.

On an average, women hit their menopause once they cross their 40s, and reach a total loss in fertility after 52. Women around these ages tend to develop signs of ageing, which is probably why men tend to show special interest in younger females, thus explaining the onset of menopause.

"This theory says that natural selection doesn't have to do anything," Singh concluded. "If women were reproducing all along, and there were no preference against older women, women would be reproducing like men are for their whole lives."

The study is published online in an open access journal PLOS Computational Biology.