Here’s why women live longer than men...

If you wondered why men don't live as long as women, you can now blame it on sex and violence in the Stone Age.

Kavita Isvaran of the Indian Institute of Science, Bangalore, and Professor Tim Clutton-Brock of Cambridge University have made this discovery and their findings were recently published in the Proceedings of the Royal Society Biological Sciences. They arrived at the conclusion after examining data on 35 birds and mammals with long life spans.

Our prehistoric ancestors lived in polygynous societies, where males kept harems and fought over them. "Intense competition over females took a toll on males and they were able to defend females for only a few breeding seasons. There was no evolutionary benefit to males in investing resources towards increasing longevity. Males evolved to be stronger and aggressive but aged faster than females," Dr Isvaran told the HT.

Isvaran and Clutton-Brock found that, in monogamous species, males and females showed similar rates of ageing and lifespan. But men have company among polygynous societies like lions, baboons, red deer and elephant seals.

"The discovery provides insights into our evolutionary past, but no moral or ethical lessons," said Isvaran.

This explains why women live on an average live to be 80 but men only 75; and queens live longer than kings.