Fenster writes:

A scientist from the University of Exeter says that “prolonged life after menopause remains one of nature’s great mysteries.”  What is the adaptive value to the selfish gene of living way beyond childbirth?

That got the researcher, Dr. Darren Croft, to look into the lifespan of the orca.  Orcas are like people in that they tend to live a long time after childbirth.  Female orcas tend to give birth in their thirties but can live another 50 years after that.

Part of the answer comes from something that the scientists knew before the study: that orcas, like a few other species, tend to stay in family groups permanently, with the mother always around to provide for and care for her adult children.   But what do mothers do, and does it make a difference?  Croft’s approach was to analyze whether adult orcas without mothers were more likely to die than those with mothers.  That might indicate that there is actual value in prolonging the mother-offspring bond.

And that is what they found, and especially so for males.

“Our research shows that, for a male over 30, the death of his mother means an almost 14-fold-increase in the likelihood of his death within the following year,” explained Dr Croft.

But for females, the chances were only three times greater for the over 30s, and remained unchanged for those that were younger.

Still unexplained is exactly how mothers care for their offspring, or what other factor would be responsible for the different death rates.

Also to be explained is how this relates to people.  Everybody is upset over the recent phenomenon of “failure to launch”.

Maybe it’s the most natural thing in the world.