![]() When the researchers blocked the activity of these two proteins in chickens, the birds developed structures that resembled snouts, not beaks. Each gene codes a protein, but the proteins - which carry out the work of genes - showed different activities in modern-day chicken and reptile embryonic development, the researchers found. "You have to understand what you're tracing before you try to trace it," Bhullar told Live Science.īhullar his doctoral advisor Arkhat Abzhanov, a developmental biologist at Harvard University and their teammates focused on two genes that are active in facial development. "It's kind of the same as fossil finding."įor their "fossil finding," the researchers needed an extensive fossil record of birds and their ancestors to see what birds looked like at different stages of their evolution. And then, the molecular work - determining exactly which developmental pathways are different, how they're different and what controls them - can take "countless hours and hundreds of experiments for a few successful ones," said the study's lead researcher, Bhart-Anjan Bhullar, a paleontologist and developmental biologist currently at the University of Chicago and cross-appointed at Yale University, where he will be starting as full-time faculty. ![]() ![]() It's difficult for scientists to get embryos of present-day animals, such as crocodiles, to compare because they have to find farms that raise them. It's likely that millions of years ago, birds and reptiles had similar developmental pathways that gave them snouts, but over time, molecular changes led to the development of beaks in birds, the researchers said. An artist rendition of the non-avian dinosaur Anchiornis (left) and a tinamou, a primitive modern bird (right), with snouts rendered transparent to show the premaxillary and palatine bones.
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