Yahoo News 26 Jun 08;
A five-year project has revolutionized 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 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."
Bird Study Reveals 10 Things You Didn't Know
Robin Lloyd, LiveScience.com Yahoo News 26 Jun 08;
Birds are among the most studied and openly stalked animals (by binocular-clad humans), but scientists have just discovered a flock of unexpected new avian facts, based on an analysis of genetic data that yielded an evolutionary tree full of surprises.
The results of this five-year study are so broad that the scientific names of dozens of birds will have to be changed in biology textbooks and birdwatchers' field guides.
"With this study, we learned two major things," said researcher Sushma Reddy, a postdoctoral fellow at the Field Museum in Chicago. "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."
Thanks to the study, here are 10 new things about birds you probably never knew:
1. Hummingbirds, colorful daytime birds, evolved from drab nocturnal birds called nightjars.
2. Perching birds (the largest order of living birds, including cardinals, orioles, crows, ravens, jays, swallows, sparrows, kinglets, weavers, chickadees, nuthatches and wrens) are closely related to parrots and falcons.
3. Flamingos and some other aquatic birds, such as grebes (freshwater diving birds) and tropicbirds (white, swift-flying ocean birds), did not evolve from waterbirds. This suggests that birds have adapted to life on water multiple times.
4. Woodpeckers, hawks, owls and hornbills look very different, but they are all closely related to perching birds.
5. Vultures, previously thought to be closely related to storks, are actually members of a group called land birds.
6. Falcons are not closely related to hawks and eagles, as was previously thought.
7. Shorebirds are not the most primitive birds (or most basal, or at base of evolutionary tree, as biologists prefer to say), which refutes the widely held view that they gave rise to all modern birds.
8. Owls, parrots and doves have few, if any, living intermediate forms linking them to other well-defined groups of birds, making it difficult to determine their evolutionary relationships.
9. Tropicbirds are not closely related to pelicans and waterbirds. In fact, bird lifestyles, such as being noctural or raptorial or ocean-going, have evolved several times, not just in one family group.
10. Birds have had a complex evolutionary history after an early and rapid explosion of species that occurred sometime between 65 million and 100 million years ago.
A total of 18 scientists, from the Field Museum, University of Florida, Gainesville, University of California, Berkeley, and Stellenbosch University in South Africa, among others, participated in the research. The results are detailed in the June 27 issue of the journal Science.
There are an estimated 82 million birdwatchers in the United States, making it the country's second most popular hobby. Gardening comes in first.
New bird family tree reveals some odd ducks
Julie Steenhuysen, Yahoo News 27 Jun 08;
The largest study ever of bird genetics has uncovered some surprising facts about the avian evolutionary tree, U.S. researchers said on Thursday, including many that are bound to ruffle some feathers.
Falcons, for example, are not closely related to hawks and eagles, despite many similarities, while colorful hummingbirds, which flit around in the day, evolved from a drab-looking nocturnal bird called a nightjar.
And parrots and songbirds are closer cousins than once thought.
The findings challenge many assumptions about bird family relationships and suggest many biology textbooks and bird-watchers' field guides may need to be changed.
"One of the lessons we've learned is appearances seem to be very deceiving," said Sushma Reddy of Chicago's Field Museum of Natural History, whose study appears in the journal Science.
"Things that are quite different-looking sometimes end up being related," she said.
For the study, Reddy and colleagues studied the genetic sequences of 169 bird species in an effort to sort out family relationships in the bird family tree.
Scientists believe birds, which first appeared roughly 150 million years ago, evolved from small feathered carnivorous dinosaurs.
"Modern birds as we know them evolved really rapidly, probably within a few million years, into all of the forms we see. That happened 65 to 100 million years ago," Reddy said in a telephone interview.
Reddy said these quick changes have made bird evolution hard to pin down, and several smaller prior studies have led to conflicting results.
"We didn't have a good sense of how any of these major bird groups were related to each other," said Reddy, who worked with researchers at several other labs.
"We've tried to represent all of the major groups of birds and all of the major lineages," Reddy said.
Their findings suggest birds can be grouped broadly into land birds, like the sparrow; water birds, like the penguin; and shore birds, like the seagull.
But there are many paradoxes within these groupings.
For example, water-loving flamingos and some other aquatic birds did not evolve from water birds. Instead, they adapted to life on water.
And some flightless birds are grouped with birds that fly.
Reddy acknowledges the results are likely to stir debate in many circles, but she said she is confident in the findings.
"I think a good study brings up as many questions as it answers," she said.
(Editing by Maggie Fox)
