Scientists believe they have resolved a human evolutionary riddle by observing orcas.
The results of the 40-year study were published on Thursday in the Journal of Current Biology.
The comparison between orcas and humans is apparently inevitable from a biological perspective since these are two of only three mammals that experience menopause. Killer whales, like humans, stop reproduction at some point in their lives.
Following orca families in the South Pacific for four decades, scientists now believe to have established that menopause gives children a better chance at survival, preventing “reproductive conflict” between mothers and daughters.
The evolutionary advantage of menopause is that younger females have greater reproductive success than their mothers when breeding at the same time. And their children are more likely to survive. When mothers and daughters co-breed, the mortality hazard of calves from the older generation of females is 1.7 times greater than of calves from younger-generation females.
Female killer whales have evolved the longest post-reproductive lifespan of all non-human animals.