Birds are living dinosaurs.
Despite the significant physical differences between a chicken and a velociraptor, they are genetically quite close. So close, in fact, that scientists trying to understand the evolutionary link between the two have been able to pinpoint specific genes relating them. But science does not end with mere pinpointing.
For University of Chile biologist Alexander Vargas, the next natural step was to manipulate the genes of chickens in order to understand just how much of their genetic baggage dates from a prehistoric era.
We spoke to Vargas, whose lab recently succeeded in growing a dinosaur leg on a chicken in the name of science, but odds are you will not be crushing a plate of dino-chicken drumsticks at your next backyard barbecue.
MUNCHIES: What is the evolutionary relationship between chickens and dinosaurs? Alexander Vargas: When you eat a drumstick, you will always find that bone that is almost like a spine, that some people find annoying. This spine-like fibula belongs to birds—only birds have evolved this. It's weird because these bones are also similar to what is found in dinosaurs.
How exactly are dinosaur legs different from chicken legs? Dinosaurs are the ancestors of birds—that is mainstream science—birds are living dinosaurs. But they have transformed from the fossil forms like the T. Rex. If you look at any of the old dinosaurs, like the T. Rex, for example, you can see that this bone (fibula) is tube-shaped and as long as the tibia, and reaches down to the ankle.
How did you make a dinosaur leg grow on a chicken? We inhibited a maturation gene called Indian Hedgehog (IHH), and that allowed the fibula to keep on growing and this resulted in a chicken that's like the old dinosaurs. It had a complete fibula reaching down to its ankle!
Why is this an important result? It shows that you can still get dinosaur leg traits in birds and I think it's very compelling. It demonstrates how strong the link is between dinosaurs and birds. There's a lot of dinosaur still left in the chicken.
Did you have a dino-chicken mutant running around the lab after your experiment? It was a chicken embryo. We just let them grow to a stage where we can see if it becomes different than a normal chicken. You can tell way before hatching time, about half the time of the incubation period that you would need before hatching.
Why didn't you let the dino-chicken hatch? We don't let them hatch because, firstly, the chicken might not be conformable and second, it doesn't answer any scientific questions that we are asking. We just wanted to see if we could grow a dinosaur leg.
What would the ethical issues of hatching a chicken with dinosaur legs? Well, for starters, you need a different bioethical permit from the lab to keep the live chickens. Scientists experiment with chicken embryos all over the world: chickens with one eye, chickens with several limbs, with crazy amounts of digits, chickens with no limbs, all kinds of monster chickens! But they never let them hatch. The main difference with our experiment is that there is an evolutionary significance.
When you look at a velociraptor, it's pretty menacing—chickens, not so much—but there is obviously a pretty close genetic link. The link has already been established. But our research shows just how much dinosaur potential is still there in the chicken. Many traits have gone, but we showed that it's not that hard to make them come back—their fibula is just like the one of the velociraptor. And a velociraptor definitely looks like what a chicken's ancestors would because they are in the group of dinosaurs closest to birds.
Theoretically, if this dino-chicken were to hatch, what would it look like? I don't think it would be too different externally from a normal chicken. Maybe you would see that the drumsticks are a bit thicker upon looking at them but nothing too striking, I'm afraid. I don't think it would have any consequences on how it moves and I don't think it would suffer because it's not drastically altered. But we don't know. We're satisfied enough with changing the morphology in the anatomy. Maybe some other people will want to risk the ethical debate and see how these chickens walk, but it's not our cup of tea.
Will people be eating roasted dinosaur chicken legs anytime soon? This is an experimental procedure that you can't repeat for any production purposes. We actually dipped some substance in there called cyclopamine and you would not want to eat that. At least, not at your early stages of development. It's called cyclopamine because it will make you into a cyclops. If you have it to early in your embryonic development, you will develop a horrible eye on your forehead. I would not eat chicken with cyclopamine.
Thanks for the cyclops warning and thank you for speaking with us. My pleasure.