For The Birds

UT Arlington profs help draw new bird family tree that has scientists chirping

UTA profs help draw new bird family tree that has scientists chirping

Spangled Continga one of hundreds of colorful and exotic birds thriving in the Cristalino Reserve
Hundreds of scientists recently collaborated as part of the Avian Phylogenomics Consortium to study the genomes of nearly 50 species of birds.  Photo by Stephan Lorenz

A global association of more than 200 scientists recently released findings from an unprecedented study regarding the genomic of birds, and two University of Texas at Arlington associate professors were part of it.

Biologists Todd Castoe and Matthew Fujita and the rest of the Avian Phylogenomics Consortium released 28 papers earlier this month detailing the genetic codes of nearly 50 birds and three crocodilian species, in the most comprehensive avian family tree to date. The research offers a big-picture understanding of how birds evolved in what is described as the avian “big bang” after the dinosaurs went extinct 66 million years ago.

Castoe says that, in an explosion of evolution, a handful of species created tens of thousands of unique species in a very short amount of time. There were also some discoveries that surprised.

“Birds that looked very similar had actually evolved multiple times,” he says. “Things like vultures from the New World and Old World aren’t related at all. They evolved from two major lineages, showing that evolution has the power, essentially, to create very similar things from very different starting points.”

Scientists believe studying how theses species evolved could eventually lead to a better understanding of the human body, in addition to the natural world.

Castoe and Fujita typically study reptilian genomes at UT Arlington, so for their part in the study, they examined three crocodilian species, the closest living relatives to birds, to see why different vertebrate groups — including humans, birds and reptiles — have such similar genetic makeups. One of their papers, “The genomes of three crocodilians provide insight into Archosaur evolution,” was published in Science journal.

Castoe says that tackling so many genomes at once helped them to understand how an organism’s phenotype, or collection of observable traits, might have previously caused scientists to place it in the wrong branch of the bird family tree.

“[These studies] will help us really understand what the vertebrate’s ancestor maybe started off with and how different lineages have taken that and changed it,” he says. “We can understand how those genetics changes relate to phenotype, which we really want to understand, and all these comparative genomes really helped us make those connections.”

As the cost of genome sequencing continues to drop, Castoe estimates that the number of species studied will continue to rise into the hundreds — up to 500 in the next five years. Invariably, he sees it as being beneficial to how scientists can work with the human body.

“We use all different kinds of species,” he says. “Mice or fruit flies are great for studies, and unless you’re doing cell cultures, you can’t do humans. Because of their exchanged physiology, maybe to find what’s good for the eye or heart, now we can use genome sequences and choose different species — not based on convenience, but on a real sound decision for the species that works.”