Menopause evolved to prevent competition between mother and daughter-in-law

The menopause evolved, in part, to prevent competition between a mother and her new daughter-in-law, according to research published today in the journal Ecology Letters.

The study explains for the first time why the relationship women had with their daughter-in-laws could have played a key role. The data showed that a grandmother having a baby later in life, and at the same time as her daughter-in-law, resulted in the newborns of each being 50 per cent less likely to survive to adulthood. The analysis helps to solve one of nature's great mysteries: why female humans, unlike most other animals, stop reproducing so early in life. It also adds weight to the theory that the menopause evolved to allow women to focus on their grandchildren. Traditionally, this role included providing food for the family and protecting young children from accidents and disease.

The study reveals that women had more grandchildren if they stopped reproducing around the age of 50. The research team believes this was partly because of reduced competition between the older woman and her daughter-in-law and partly because of the support she could offer her grandchildren.

Source