More than two decades after dinosaurs crashed the electric fences in Jurassic Park, the fourth installment in the series—Jurassic World—has once again delivered hapless tourists to the claws and jaws of genetically engineered monsters. But even though everyone knows this is science fiction, headlines and high-profile articles about de-extinction have let fiction stalk a little closer to reality.
So will we ever see a real Jurassic World?
Not like in the movie, no, but some paleontologists are exploring another way to revive dinosaur traits, by reverse-engineering birds to look more like their dinosaur ancestors.
Let’s get the fiction out of the way first. The way Jurassic World’s geneticists created their toothy attractions was close to how Michael Crichton envisioned in his original novel.
Starting with tatters of DNA extracted from prehistoric mosquitoes and biting insects, the fictional scientists plug the gaps with genes from living animals to cobble together creatures that look like real dinosaurs. (Never mind all the complicated steps to get from genes to living organisms. That’s a problem for the dinosaur breeders at Site B.)
While this fictional scheme for bringing dinosaurs back to life was ingenious, it’s never going to happen. (That's one of the facts I had to cope with as science adviser for the new movie’s official website.) The genetic material just doesn’t last long enough. DNA starts to decay at death, and, given its decay rate even under ideal conditions, there’s little hope of obtaining even a shred of DNA from fossils any older than 6.8 million years.
That’s far too recent for Tyrannosaurus and Triceratops, much less even earlier dinosaurs that flourished between 235 and 66 million years ago. Fossils can preserve the structure of collagen fibers and blood cells, but it’s unlikely that a researcher is ever going to jump up from the lab bench and shout “Bingo! Dino DNA!”
Instead of bringing ancient DNA to life, scientists are thinking about how to work backward from modern DNA. These plans are a bit closer to some of the experimentation in the new blockbuster, in which geneticists rearrange genes to create animals that better fit the local environment and visitor expectations. They’re not “pure” dinosaurs, but custom creatures rebuilt to spec.
Birds are living dinosaurs. They’re not quite like a Stegosaurus or Apatosaurus, true, but they’re another line of dinosaurs that sprouted about 150 million years ago and survived while all their relatives went extinct. And since birds' genes hold clues to their prehistoric past just as their anatomy does, some scientists are looking to these living dinosaurs to reconstruct their long-lost relatives.
Paleontologist Jack Horner, consultant on the Jurassic Park films from the outset, has received a great deal of press for presenting this idea as the “chickenosaurus” project. By tweaking the genes and development of chickens, Horner and others have proposed, researchers can create a bird that looks like a Velociraptor.
Some of the necessary changes to create a chickenosaurus are already starting to come together. In 2006 biologist Matthew Harris found that chicken embryos can grow rudimentary teeth. Then, just last month, a pair of independent studies were able to make birds more Velociraptor-like.
After discovering that the perching toe of modern birds starts to develop only once embryos start twitching their muscles, biologist João Francisco Botelho and colleagues paralyzed that toe in developing birds and found that it retained the ancestral anatomy seen in non-avian dinosaurs.
Around the same time, geneticist Bhart-Anjan S. Bhullar of Harvard and coauthors announced that they were able to create experimental chickens that lacked beaks and had jaws closer in form to those of dinosaurs like Velociraptor. With a few more changes—such as a long, balancing tail—scientists will be pretty close to making what’ll look like a Cretaceous cockerel.
This method won’t let us bring back Velociraptor or Tyrannosaurus. Those dinosaurs are long gone and are never coming back. Instead, a chickenosaurus would be closer to Jurassic World’s fictional villain Indominus rex, a hybrid of various genes from dinosaurs and other creatures, or even elephants genetically modified to look like mammoths. It wouldn’t be a moment of resurrection, but reinvention.
Whether anyone ever trots out a “chickenosaurus” on live TV isn’t really the point, though. The real goal of these studies is understanding the relationship between genetic change, development, and anatomy that underscored one of the most wonderful evolutionary transitions of all time. Taken together, they could reveal what happened to both genes and anatomy as birds emerged from their dinosaurian ancestors.
Bones provide the roadmap, but the traits of living birds may yield some of the step-by-step directions to get from point to point. And that’s what the fictional paleontologist Alan Grant knew well. We can learn so much about dinosaurs because some of them are still with us. Look outside and watch the chickadees, quail, and ravens. We still live in a Jurassic World.