Colourful birds 'evolve faster'
Melbourne: Colourful birds evolve into new species faster than those with only one colour form, according to a new research.
A team at the University of Melbourne has found that avians with multiple plumage colour forms within in the same population evolve faster, confirming a 60-year-old evolution theory, the 'Nature' journal reported.
The study used information from birdwatchers and geneticists accumulated over decades.
The link between having more than one colour variation (colour polymorphism) like the iconic red, black or yellow headed Gouldian finches, and faster evolution of new species was predicted in the 1950s by famous scientists such as Julian Huxley, but this is the first study to confirm the theory.
"By confirming a major theory in evolutionary biology, we are able to understand a lot more about the processes that create biodiversity. 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," Dr Devi Stuart-Fox, who led the team, said.
The team focused on birds because although colour polymorphism occurs in many animals (such as fish, lizards, butterflies and snails), there is a wealth of information on colour variation in birds, as well as on species classification (taxonomy), partly thanks to birdwatchers.
"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," Dr Stuart-Fox said.
By modelling evolutionary rates using publicly available genetic information accumulated over a quarter of a century, the study found that colour polymorphism speeds up the generation of new species.
The study found that colour polymorphic species were younger not only in the birds of prey but in the songbirds, which account for more than half of the world's bird species.