A group of developmental biologists led by Bhart-Anjan Bhullar of Yale University have turned back the clock on evolution. They were studying how chicken beaks evolved over millions of years from dinosaur snouts. So, Bhullar and his colleagues manipulated proteins in embryonic chicken cells to turn the bird’s beak into a dinosaur-like snout during their developmental stages.
Why didn’t researchers let chicken embryos hatch?
Findings of the study were published Tuesday in the journal Evolution. Bhullar said the goal was not just to create a ‘dino-chicken.’ Their goal was to understand an important evolutionary transition at a molecular level. That’s why researchers did not allow these chicken embryos to hatch. Though it may sound easy, creating dinosaur snouts from chicken beaks was a challenging task.
Scientists began by determining the gene expression that correlated with the evolutionary transition. To achieve this, they examined the evolutionary history of chicken with the help of fossil records and other animals such as lizards, crocodiles, and turtles. They also examined the skeletons of modern birds, extinct birds, modern reptilian relatives of birds, and extinct dinosaurs.
Researchers pinpoint when chickens developed their modern beak
Researchers then cloned DNA fragments from some animals to identify the gene expression to form the snouts of dinosaur species like Velociraptor and Archaeopteryx. They further studied the bones of embryos, juveniles and adults to understand how the anatomy of the birds’ ancestors evolved over millions of years.
Bhullar said they used molecule inhibitors to block proteins that develop modern chicken beaks. Thus they successfully reverted the beaks of chicken embryos into dinosaur snouts. Though researchers did not allow these embryos to hatch, Bhullar noted, “They actually probably wouldn’t have done that badly if they did hatch.”
Biologists pinpointed the exact moment in chicken’s evolution when it developed modern beak. Bhullar said other biologists could use this method to examine the evolutionary history and transformation of other species.