A new study published in the British journal Proceedings of the Royal Society B, provides mathematical evidence to support the theory that grandmothers may have played a major role in lengthening the human life span.
Kristen Hawkes, a distinguished professor of anthropology at the University of Utah, and her colleagues first proposed the grandmother hypothesis in 1997. Now Professor Hawkes, lead author of the current study, presents simulation models that show how the grandmother effect could have produced overall gains in human longevity.
Hawkes notes that in prehistoric times, women rarely lived past their child-bearing years. Those women whose mothers did survive to help with child-rearing and food gathering were able to have more children at more frequent intervals because they had help taking care of the older children. Thus, the genes in the surviving grandmothers that led to the increased longevity were passed on to more and more humans and eventually led to an overall increase in lifespan for all humans.