Traditional theory of evolution maintains that it's the good-looking male that gets the ladies, but a new study might prove otherwise. Research by the University of Queensland (UQ) has found there is a limit to the success of even the most desirable males in a population, reports ABC Science.
After genetically engineering flies to make them more attractive, the researchers found that they quickly increased in the population from 12 per cent to 35 per cent of the population, but levelled off after seven generations.
"We don't know what the cost is to fruit flies. They are still able to produce offspring and live long enough, but there's some cost we can't see," said Dr Katrina McGuigan.
The UQ researchers suggest an opposing force, natural selection, is at play as well, putting the brakes on sexual selection when those attractive attributes also confer some sort of disadvantage to the male.
"While these selected male flies were highly attractive, they also suffered disadvantages - likely to be lower survival rates as larvae," said Associate Professor Mike Schwarz from the School of Biological Sciences at Flinders University in Adelaide.
"Emma Hine and her coauthors therefore seem to have found the hypothesized 'brake' on the limits of sexual selection."
"It also implies that those amazing sexual displays males have, such as peacock tails, have probably in part evolved not because of sexual selection, but because of changes in the environment. There has to be a habitat shift before sexual selection can start to drive evolution," said McGuigan.
The study appears in this week's Proceedings of the National Academy of Sciences.