Study: Mother-daughter conflict can explain why killer whales go through menopause

Mother-daughter conflict can explain why killer whales are one of only three known species of mammal, including humans, to go through the menopause, researchers said Thursday.

Using 43 years of demographic data on killer whales, the study published in the U.S. journal Current Biology, found that when mothers and daughters breed at the same time, the offsprings of the old-generation females are 1.7 times more likely to die than those of younger females.