In Jurassic Park and Jurassic World, the storylines rely on ancient amber preserving dinosaur DNA. In actuality, this isn’t possible, which means that scientists can’t use this technique to bring back the dinosaurs. But that doesn’t mean dinosaur genes went extinct. We’re actually still living in the age of the dinosaurs—they just don't look the way you might expect. Modern-day birds are offering clues as to how dinosaurs lived—and how they died.
Jurassic World’s Wrong About DNA
Published June 27, 2018
Onscreen : In Jurassic World , long-extinct reptiles are resurrected. It all hinges on a key ingredient: ancient dino DNA. But does that exist?
In the movies, it comes from dino blood preserved in ancient mosquitos, trapped in amber. In reality, scientists have found remnants of dinosaur blood in the bellies of dino-era ticks and mosquitos. But no dino DNA. They've found a chunk of dino tail preserved in amber. But no dino DNA.
Yes, scientists have extracted what may be dino protein from fossils. But where's the DNA? It comes down to chemical composition. DNA decays faster than protein.
Bhart-Anjan Bhullar : DNA, it's a fairly fragile molecule, breaking and coming back together in your body all the time. Whereas protein, it's built for resilience. That's the stuff that holds our bodies together.
Onscreen : Quality DNA seems to have an expiration date, like milk or bread. It just takes way longer to go bad. By looking at how DNA degrades over time, we can predict its shelf life—up to 6.5 million years. But dinosaurs lived at least 60 million years before that expiration date.
Bhullar : We don't have dinosaur DNA because they died out far, far too long ago.
Onscreen : So ancient DNA seems unlikely. Luckily, DNA persists by making imperfect copies of itself. Traces of dino DNA are now packaged inside birds, which are direct descendants of dinosaurs.
Bhullar : So it's still the age of dinosaurs. The structure of a bird screams, “This is something that's a heavily modified dinosaur.”
Onscreen : So to study dinos, you can study birds. Like chickens.
Anthony Russell : What do you think about a dinosaur the size of a chicken? Well, a chicken is a dinosaur the size of a chicken.
Onscreen : For instance, dino fossils often have this haunting "death pose." But we didn't know why. Arched fossil necks gave the impression of agony in death. But studying dead chickens from the supermarket suggest it may be due to anatomy.
Russell : We found there's resistance to bending downwards, but there's not a resistance to bending back.
Onscreen : Scientists are also taking a molecular approach by modifying chicken development to reconstruct ancient dinosaur anatomy.
Bhullar : The development of an embryo, it's as close as we can get to the mechanism of dinosaurs becoming a bird without a time machine.
Onscreen : Bhart-Anjan Bhullar has reverted the chicken beak into something more dino-like in the embryo. Others have done the same thing with chicken toes, fingers, and legs, supporting the idea that birds have ferocious ancestry. But turning chickens into dinos isn't likely.
Bhullar : The roadblock now is that even in humans, even in fruit flies, we don't understand how the genome itself is controlled.
Onscreen : That control determines which DNA instructions are accessible during development. So we may never dinosaur-ify birds enough. But bringing fossils and modern dinosaurs together paints a clearer portrait of a lost world, and lets us admire the dinos that survived.
PRODUCTION CREDITS Digital Production Tiffany Dill Production Assistance Ari Daniel & Aparna Nathan Editorial Review Julia Cort © WGBH Educational Foundation 2018 MEDIA CREDITS Visuals Bhart-Anjan Bhullar
Royal Saskatchewan Museum/R.C. McKellar
wikipedia Music APM POSTER IMAGE (main image: T Rex roaring) "Jurassic World" trailer