Scientists have released the most comprehensive bird 'family tree' ever created, by using genetic data from 48 different species to trace how modern bird ancestries flourished after the mass extinction that killed off the dinosaurs.
The work was conducted by researchers from 20 countries and helps clarify the evolutionary relationships of modern bird groups. It also reveals the genetic underpinning of traits like singing, toothlessness and colorful feathers, according to the study, published on Thursday in the journal Science.
Scientists were able to decode the genomes, an organism's genetic material, of 45 bird species and analyzed those of three others sequenced at an early date.
The list covered just about all living bird groups. Species mentioned in the list include: penguins, falcons, eagles, woodpeckers, owls, vultures, pelicans, cranes, crows, hornbills, cormorants, hummingbirds, pigeons, ducks, chickens, turkeys, ostriches, finches, loons, flamingos, swifts, and even the White-throated Tinamou, according to a press release
"We have produced a well-resolved bird family tree and provided a clear picture of how the modern birds originated and evolved," said geneticist Guojie Zhang of the BGI genome research center in Shenzhen, China and the University of Copenhagen, according to Reuters.
Scientists believe birds evolved from small, feathered dinosaurs. The earliest known bird, Archaeopteryx, lived nearly 150 million years ago. They believe that most bird lineages from the age of dinosaurs were killed off during the mass extinction some 65 million years ago.
"Birds are dinosaurs. They're the one lineage of dinosaurs that made it through the mass extinction," University of Florida biology professor Ed Braun said, according to Reuters.
The study focused on a group called Neoaves, which includes almost all of today's 10,000-plus bird species. The evolutionary explosion took place 10 to 15 million years after the mass extinction.
This "big bang" broadening of species resulted in 95 percent of today's birds, Duke University Medical School neurobiologist Erich Jarvis said, according to the release.
Large flightless birds like the ostrich were confirmed as the family tree's oldest branch. Scientists said the chicken genome is probably the closest of any species to the ancestor of birds.
Their research found singing evolved independently in songbirds, parrots and hummingbirds.
Believe it or not, crocodiles were found to be birds' closest living relatives, with the common ancestor 240 million years ago, according to the release.