Why females live longer than males

Male flies die earlier than their female counterparts when forced to evolve with the pressures of mate competition and juvenile survival. The results could help researchers understand the mechanisms involved in aging.A study of the fly Drosophila simulans has revealed that males court females by singing, dancing and smelling good, but their efforts come at considerable cost and this cost is amplified when they also have to cope with stressful temperatures.The study shows that mate competition (sexual selection), along with survival (natural selection), is tougher on male aging than it is on females reducing their lifespan by about a third.
Some species age quickly over a number of days while others like some trees and whales, age slowly across centuries. The results of the study showed that under relaxed sexual and natural selection, male and female flies had very similar lifespans of around 35 days. However males that evolved under elevated sexual selection and elevated natural selection had a much shorter lifespan of just 24 days and died seven days earlier than females under the same conditions. Both sexual selection and natural selection were found to affect lifespan but their effects were greatest on males. The findings show that the sexes can respond differently to the same selection regimes.