Mate competition and survival is tougher on males than on females, reducing their lifespan by about a third, a new study on flies has found. The study from the University of Exeter has found that 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 ageing.
The research used populations of the fly Drosophila simulans that had evolved under different selection regimes. The study shows that mate competition (sexual selection), along with survival (natural selection), is tougher on male ageing than it is on females reducing their lifespan by about a third. Some species, like the flies in this study, age quickly over a number of days while others — including some trees and whales — age slowly across centuries.
“We found dramatic differences in the effects of sexual and natural selection on male and female flies. These results could help explain the sex differences in lifespan seen in many species, including humans, and the diverse patterns of ageing we observe in nature,” Professor David Hosken from Biosciences at the University of Exeter said.
The flies were subjected to elevated or relaxed sexual and natural selection and left to evolve in these conditions.