Colourful birds evolve faster

Sydney, May 14 (IANS) Researchers have discovered that bird species with multiple plumage evolve into new species faster than those with only one colour form, confirming a 60-year-old evolution theory.

The link between having more than one colour variation (colour polymorphism) like the iconic red, black or yellow headed Gouldian finches, and the faster evolution of new species was predicted in the 1950s by famous scientist Julian Huxley.

The global study used information from birdwatchers and geneticists accumulated over decades and was conducted by University of Melbourne scientists Devi Stuart-Fox and Andrew Hugall (now at Melbourne Museum), the journal Nature reported.

By confirming a major theory in evolutionary biology, we are able to understand a lot more about the processes that create bio-diversity said Stuart-Fox, zoologist from Melbourne.

"We found that in three families of birds of prey, the hawks and eagles, the owls and the nightjars, the presence of multiple colour forms leads to rapid generation of new species," Stuart-Fox said, according to a university statement.

"Well known examples of colour polymorphic species in these families include the Australian grey goshawk which has a grey and pure white form, the North American eastern screech owl and the Antillean nighthawk, each with grey and red forms," said Stuart-Fox.

"We looked at five bird families with a high proportion of colour polymorphism and compared their rates of evolution with those with only one colour form," Stuart-Fox said.

Study co-author Andrew Hugall said: "Using many decades of natural history information and 25 years of genetic sequence information we were able to generate the massive family trees, such as a tree of more than four thousand songbirds, needed to model rates of bird evolution in this study."