Lifespan gaps are influenced by both genetics and environment, with larger differences seen in the wild compared to zoo settings.

Even in zoos, where predators and harsh conditions are minimized, male-female longevity gaps persist, indicating underlying biological and evolutionary drivers.

Parental investment affects longevity: the sex that invests more in offspring, typically females, tends to live longer, especially in long-lived species like primates.

Overall, parental care contributes to longevity, suggesting selective advantages for longer lifespans in species with substantial offspring investment.

The findings suggest lifespan differences are deeply embedded in evolutionary history, shaped by sexual selection, parental investment, and genetic factors, and likely to persist.

A comprehensive study shows that, across mammals and birds, women generally outlive men, a pattern rooted in evolution and genetic factors.

Longevity is influenced by mating systems: strong male competition in polygamous mammals links to earlier male death, while monogamous birds often see males living longer than females.

The heterogametic sex hypothesis connects sex chromosome composition to lifespan differences, with mammals (females XX, males XY) and birds (females ZW) showing patterns that align with observed longevity, though not universally.

The study is published in Science Advances under the article titled 'Sexual selection drives sex difference in adult life expectancy across mammals and birds.'