Wild Things

How Impossible, Actually, Is the Dinosaur DNA Splicing in Jurassic World?

The Indominus rex is part raptor, part cuttlefish, part God knows what else.


By the time Jurassic World begins, dino-making is yesterday’s news. Brontosaurs? Boring. Triceratops? Over it. The “science” that made all the wonder in the first film possible—extracting DNA from ancient mosquitoes, filling in the gaps with frog genes, and whisking it all together to grow a real live dinosaur—it’s all been done. “Let’s be honest,” says Claire Dearing, the park operations manager in Jurassic World. “No one’s impressed by a dinosaur anymore.” 

So now what? To restore a sense of wonder to the jaded masses, we’re going to need something bigger, better, and altogether grander: a dinosaur that can transcend the pesky laws of nature. Armed with test tubes and hubris, scientists set out to design their own, tricking out the T-Rex genome with strands of cuttlefish and tree frog DNA to create a custom-made methuselah: the Indominus rex. After all, why mimic Mother Nature when you can outdo her? 

Clearly, there’s a lot here to set off your scientific BS radar. But just how implausible is it to think that we could engineer a mega-creature out of a patchwork of different animals’ DNA?

First off, the idea of designing a dino is hardly as far-fetched as it once was. In the two decades that have elapsed since Jurassic Park came out in 1993, we’ve made massive breakthroughs in dino genetics and developmental biology. Some scientists—namely Jack Horner, the paleontologist who inspired Jurassic Park’s Alan Grant and dino advisor on Jurassic World—are even talking about reverse-evolving a chicken back into a dinosaur. Theoretically, we could “turn back the evolutionary clock” by breeding a chicken backward to unlock ancient genes that control dinosaur characteristics like teeth, scales, and talons. And ta-da: a chickenosaurus!

But in this scenario, scientists are merely working with what they’ve got: a chicken genome with some evolutionary holdovers. Blending entirely different species will require a little more imagination. Just ask the scientists trying to bring back the woolly mammoth by splicing mammoth genes into the modern elephant genome or others trying to resurrect the extinct passenger pigeon by grafting its DNA onto a living pigeon’s. The good news: “It’s not impossible,” says Robert DeSalle, a geneticist at the Sackler Institute for Comparative Genomics and co-author of The Science of Jurassic Park and the Lost World or, How to Build a Dinosaur. “The technology already exists.” 

In fact, the technology for combining unlike genomes isn’t just a dream. We’ve been making mutant hybrids for years: They’re called GMOs. Scientists have created strawberries augmented with antifreeze genes from Arctic flounder fish and oranges injected with disease-fighting genes cultivated from pigs.* Outside of crops, scientists have been tinting zebra fish and leopard gecko embryos with green fluorescent proteins from jellyfish and corals so they can watch them develop for decades now. So where are the rhinosauruses? Or the Clairodactyl, that rare hybrid that can fly long distances in heels? 

Well, there’s just one problem: Dinos are not like strawberries. In the case of GMO crops, we’re talking about isolating one gene that codes for one specific trait. In the case of Jurassic World, we’re talking about traits that involve hundreds of genes. Take camouflage, the trait that (spoiler alert!) so surprises the Indominus rex’s trainers. Blending in with your surroundings requires tweaks to neural genes, skin genes, hormonal genes, and temperature sensitivity genes. “It’s likely a whole suite of genes,” says Beth Shapiro, a professor of ecology and evolutionary biology at the University of California at Santa Cruz and author of How to Clone a Mammoth: The Science of De-Extinction.

In other words, it’s not a simple matter of genetic cutting and pasting. “When genomes evolve, they don’t do so in isolation,” says Shapiro. “They do so in the background of the entire genome.” Many of the genes you’re messing with are pleiotropic—that is, they code for several different characteristics. And it’s not like all of them are located in one place; they’re distributed all over the genome. You start to appreciate the difficulty. Shapiro compares the challenge to trying to swap out an elephant’s forelegs for wings. “I can’t cut out a wing gene, insert into an elephant, and assume I’m going to get an elephant with wings,” she told me, not without a touch of exasperation. “There is no wing gene.” 

There’s a bigger reason this wouldn’t work. Though we’ve sequenced hundreds of animal genomes, we still don’t know exactly how each one functions as a whole. You might say we have the vocabulary to describe the language of biology, but we haven’t yet mastered the grammar. As DeSalle puts it: “We’ve had the chicken genome sequences for a decade now—and we still don’t know chickenshit about it.”

So Jurassic World is right: In reality, injecting a complex trait into a foreign genome would be like trying to transplant a nonnative species into a delicate island ecosystem. (Which, it turns out, is exactly the plot of Jurassic Park.) No matter how careful you are, you can never predict the complex chain of interactions that will occur. The only thing you can predict is that you’re probably going to break the entire system—and make a pretty dramatic movie while you’re at it.

“You’re talking about mixing and matching across evolutionary barriers that have been separate for hundreds of millions of years,” says David Blockstein, a senior scientist at the National Council for Science and the Environment and the head of the Passenger Pigeon Project. “It’s hard to imagine that would work.”

But Jurassic Park was never about deconstructing the science of de-extinction. It was about entertaining the impossible. To watch Jurassic World is to experience the same chills of possibility you feel when Frankenstein’s monster comes to life, or when H.G. Wells’ time traveler turns on his machine for the first time. For a moment, man is larger than himself, surveying the whole of creation, his spirit as indomitable as … well, as the Indominus rex. 

Then, of course, he gets eaten.

Read more in Slate about the Jurassic Park movies.

*Correction, June 19, 2015: This article originally misstated that most of us eat GMO strawberries and oranges. These GMOs are not yet on the market.