ACADEMICS in Sheffield researching human development think the menopause developed to prevent competition between a mother and her new daughter-in-law.
The study – published in the journal Ecology Letters – explains for the first time the relationship between women.
The data showed 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.
They say the analysis helps to solve one of nature’s great mysteries - why female humans, unlike most other animals, stop reproducing so early in life.
Dr Virpi Lummaa from the University of Sheffield - who conducted the research in collaboration with other scientists across the globe, said: “It is interesting that even today, mothers rarely choose to have children at the same time as their offspring, even if they have not yet been through the menopause.”