Researchers have found that bird species with multiple plumage colour forms within in the same population, evolve into new species faster than those with only one colour form, confirming a 60 year-old evolution theory. The global study used information from birdwatchers and geneticists accumulated over decades and was conducted by University of Melbourne scientists Dr Devi Stuart-Fox and Dr Andrew Hugall (now based at the Melbourne Museum) and is published in the journal Nature.
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 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 said Dr Devi Stuart-Fox from the University's Zoology Department. “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 Stuart-Fox said. “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.”