’Most attractive’ male birds don’t have the best genes

'Attractive' male birds that mate with many females aren't passing on the best genes to their offspring, according to new UCL research which found promiscuity in male birds leads to small, genetic faults in the species' genome. Although minor, these genetic flaws may limit how well future generations can adapt to changing environments. The study, published this week in Proceedings of the National Academy of Sciences and funded by the European Research Council, shows for the first time the power of sexual selection - where some individuals are better at securing mates than others - in shaping broad patterns of genome evolution. Study author, Professor Judith Mank, (UCL Genetics, Evolution & Environment), said: "We've found that promiscuous bird species that have to fight others for mating rights have a genome that evolves faster than bird species which are monogamous and pair for life. What's interesting is that this evolved genome includes mildly negative mutations. So a male may be attractive to a female and fight hard to mate with her but he doesn't deliver at the genetic level. As a result, his descendants will be less fit." The researchers studied a 90 million year old group of birds called the Galloanserae which including the mallard duck, swan goose, wild turkey, helmeted guineafowl, Indian peafowl and common pheasant.