Shaking Up the Bird Family Tree
The bird family tree may look a little different than previously thought. A study published this week in Nature is just one of at least 28 scientific papers to come out of the Avian Genome Consortium, a team effort involving some 200 scientists. The researchers sequenced the DNA of 48 bird species—a massive undertaking that harnessed supercomputing power at UT’s Texas Advanced Computing Center and involved two UT computer scientists.
Because there are more than 10,000 wildly different species of birds, which evolved from dinosaurs approximately 65 million years ago, mapping their evolution is a daunting task that has evaded scientists for years. But this first-of-its kind project brings a new clarity to our understanding of avian evolution. “It looks like we might be converging on an answer,” says Julia Clarke, a UT professor and avian paleontologist who spoke with the Alcalde about the new findings.
Why is this set of studies such a big breakthrough?
The relationships among major groups of birds have been tricky to figure out. This is the largest-scale analysis ever brought to bear on figuring out how groups like penguins, parrots, songbirds, and raptors are related. What’s most exciting is that now we can use these data to move forward on the evolution of specific characteristics, aspects of song learning … it’s going to move forward all our work on the genetic basis for innovation in birds. It’s really shaken up the tree, if you will.
What are some of the findings that have shaken up the tree?
One of the things this study confirms—it’s not novel to the study—is the idea that our raptors actually evolved multiple times. Under traditional classifications falcons, hawks, and eagles were all [in the same category]. Now we see evidence that they’re not all one group. [Now] falcons come out with parrots and songbirds. This suggests that perhaps parrots and songbirds come from a lineage that would have had this raptor-like ecology. Which is really cool, because those aren’t groups of birds people would think of as being closely related.
If you’re a bird-watcher—and here in Central Texas we have one of the richest areas for avian diversity in North America—then perhaps by looking at some of these new relationships, you’ll see the birds outside your window in a new way.
You study avian paleontology. With that background, what’s your perspective on this research?
Figuring out the evolutionary relationships among birds has really been a renaissance because with the molecular revolution, we’ve been able to get larger and larger data sets. I work a lot on evolutionary intervention; I’m interested in how novel traits arise that may influence what kinds of ecologies and behaviors you see in a group. Once you’re studying whole genomes, there’s a lot more potential for trying to look for a link between aspects of the bird and their genetic underpinnings. That kind of analytical toolkit is coming on the scene and is very exciting.
Why study avian evolution? Are there implications outside of ornithology?
We’re primates. We have all these features like binocularity, bipedalism, and complex vocal communication. Birds have those traits too. I like to call them our feather doppelgangers. We only have a couple of instances in the entire tree of life of some of those traits. And I think that’s compelling to have that perspective. They share more features with us than we may be comfortable recognizing. We like to think of ourselves as really exceptional, but maybe we’re less alone in the tree of life than we thought.
A Central American pygmy owl. Photo by Shawn McCready.
