Study proves scientists wrong
2008-06-27 09:13
Washington - A five-year project has revolutionised scientific thought on the evolution of birds and the results are so surprising that now even the textbooks will have to be rewritten, a study said on Thursday.
"With this study, we learned two major things," said Sushma Reddy, lead author and a fellow at The Field Museum in Chicago, Illinois.
"First, appearances can be deceiving. Birds that look or act similar are not necessarily related. Second, much of bird classification and conventional wisdom on the evolutionary relationships of birds is wrong."
The results of the largest ever study of bird genetics are so widespread that the names of dozens of birds will now have to be changed, says the study to be published in Science magazine.
The Early Bird Assembling the Tree-of-Life Research Project has been researching the evolution of all major living groups of birds and has already examined 32 kilobases of DNA data in 19 places of some 169 bird species.
A kilobase in molecular biology is a unit of length for DNA fragments representing 1 000 base pairs of DNA.
Among new discoveries the team found that birds repeatedly adapted to new environments. For example, flamingos and grebes did not evolve from other waterbirds, while birds that now live on land such as cuckoos did not evolve from other landbirds.
Other findings were that, contrary to current thought, daytime hummingbirds evolved from nocturnal nightjars, falcons are not related to hawks and eagles and fast flying ocean birds are not related to pelicans and other waterbirds.
"We now have a robust evolutionary tree from which to study the evolution of birds and all their interesting features that have fascinated so many scientists and amateurs for centuries," Reddy said.
"Birds exhibit substantial diversity and using this 'family tree' we can begin to understand how this diversity originated as well as how different bird groups are interrelated."