The study – by researchers from the University of Turku (Finland), University of Exeter (UK), University of Sheffield (UK) and Stanford University (US) – 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.
Read more at ScienceBlog.