Why killer whales and human females stop breeding early?
London, July 2 (IANS) The evolutionary mystery of menopause is a step closer to being solved, thanks to new research on killer whales. A study by the Universities of Exeter and Cambridge has found a link between killer whales, pilot whales and humans – the only three known species where females stop breeding relatively early in their lifespan. Despite very different social structures between the three species, the research shows that in each case females become increasingly genetically related to those they live with as they get older. Because of this, there is a motivation for older females to do what is best for the survival of those around them. This creates a ‘grandmother’ role, where the success rate of breeding in the group can be helped by older females sharing parenting knowledge and stopping breeding to allow younger females easier access to resources. The research is the first to provide a plausible explanation why these species in particular are the only ones in which female
