A new research on killer whales could help solve the evolutionary mystery of menopause.
Scientists at the Universities of Exeter and Cambridge have found that killer whales, pilot whales and humans are the only three known species where females experience menopause.
The study cites the reason as increasing genetic relations with those they live, in each case, creating a 'grandmotherly' role, where the older ones share parenting knowledge.
Dr Michael Cant, from the University of Exeter's School of Biosciences (Cornwall Campus) and a Royal Society University Research Fellow said that by contrast with humans and menopausal whales, in other long lived mammals it is typically males who leave the group to breed, and females who stay with their mother.
Dr Rufus Johnstone, from the Department of Zoology at the University of Cambridge, and co-author of the study, said, "This isn't likely to be the only factor relevant to the evolution of 'grandmothering' and menopause, but it does give us an idea why it is restricted to so few species in the animal kingdom."
The research is published in the Proceedings of the Royal Society B.