Menopause is an exclusive trait, shared only among humans, killer whales, and short finned pilot whales. According to a new Current Biology study, killer whales go through menopause to avoid reproduction competition with their daughters, allowing them to instead share knowledge to help their family succeed. This explanation also sheds light on why humans share this unique trait with toothed whales.
Darren P. Croft, an animal behaviorist at the University of Exeter, and colleagues used 43 years of demographic data on killer whales to investigate menopause. The evolutionary benefit became clear when they found that in cases where mothers and daughters do have calves at the same time, the calves of the old-generation females are 1.7 times more likely to die than the calves of younger females.
We spoke with Croft to find out more....
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