Researchers from Harvard and Yale are trying to reverse evolution by genetically engineering a chicken with a dinosaur snout. By taking this approach, they hope to learn more about the million years-old molecular process that lead dinosaurs to develop bird beaks.
The research team altered the normal molecular process, and the results were weird, but spectacular nonetheless. They managed to create chicken embryos with snouts similar to those of small feathered dinosaurs called Velociraptors.
“Our goal here was to understand the molecular underpinnings of an important evolutionary transition,” explained project co-leader Bhart-Anjan S. Bhullar, a Yale paleontologist and developmental biologist. Bhullar argued that the resulting ‘dino-chicken’ is just a funny coincidence, and not the whole purpose of the experiment.
The study was published on 12 May, in the journal Evolution. The paper’s other co-author is Harvard University’s Arhat Abzhanov.
The scientists chose to replicate how to the bird beak evolved because they believe it is a crucial moment in the evolutionary process. There are over 10,000 bird species in the world, spread across very different habitats, each one with its own distinctive anatomy, but what they all have in common is the beak.
The team believes the reversed evolutionary approach is the most effective way of understanding the mechanism behind the radical transformation. The biologists were guided by the dinosaur fossils discovered earlier to help them decide where to start from.
Before making any molecular alterations to the chicken embryos, they first tried to identify genetic patterns among the fossils, suggesting when and how the transformation began. They also compared genes of existing animal species, such as alligators, emus or turtles.
Eventually, they were able to isolate the specific cluster of genes in charge of facial development in birds, since it was the one missing from the non-beaked species. Further, the researchers managed to inhibit the proteins responsible for the development of the beak. And then, they watched.
The results were spectacular: when the chicken skeletons began to form, instead of growing a beak they had short, broad snouts, similar to those found on Velociraptors, or on the ancient bird Archaeopteryx. As far as it goes for the dino-chicken, the outcome was not intended but the researchers welcome it anyway.
“This was unexpected and demonstrates the way in which a single, simple developmental mechanism can have wide-ranging and unexpected effects,” Bhullar explained. The Yale scientist believes the new approach opens the door to study a wide range of evolutionary transformations, as the same method can be used to decipher other mechanisms.