Why Men Evolve Faster Than Women

Scientists have found that men are evolving faster than women because of sexual promiscuity and the intense competition that arises in the fight to secure mates. An investigation into the genes of apes and humans has found that male DNA has undergone a more rapid rate of change during evolution.

The University of Chicago scientists found that reproductive genes - in men those instructions involved in sperm production - evolved faster in human and chimp males than in females of either species, or gorillas of either sex.

Professor Chung-I Wu said the research, published in Nature, says more about the competition between men than the battle of the sexes. "The simplest explanation is that sperm compete for eggs but eggs don't compete for sperm," he said.

"The pressure on a male to find a mate and fertilise her eggs is constant. Presumably, genes governing male reproduction are under pressure to evolve."

The researchers concentrated on the genes involved in producing protamines, which bind to sperm and are crucial for ensuring fertility. They found that the genes of chimps and men were radically different, indicating a rapid rate of evolution. But the genes of gorillas were evolving at a slower pace.

Professor Wu believes this is explained by the different mating strategies. Chimps - and possibly early humans - are promiscuous. Gorillas have harems where one male exclusively entertains a captive audience, thus are more sure of being the father of any offspring.