Jack Horner has a vision. A world-famous paleontologist who gives “an awful lot of lectures,” Horner pictures himself strolling out on stage before a crowd, just as he’s done countless times before. Instead of carrying the standard sheaf of notes or dusty slides, though, he has with him the ultimate prop: a real live dinosaur on a leash. “It’s small, but bigger than a chicken,” he writes in his new book, How to Build a Dinosaur. “Let’s say the size of a turkey, one day maybe even the size of an emu.” The emu-size dinosaur, he adds, “might have a muzzle or a couple of handlers.”
If it sounds straight out of Jurassic Park, it’s no coincidence: Horner served as scientific advisor on all three films, and is said to be an inspiration for the rugged protagonist, Alan Grant. Unlike in the movie, though, Horner thinks he can bring back a dinosaur without using its DNA—a crucial difference, because in real life, dino DNA hasn’t been recovered. Horner has a different plan. By making a few genetic tweaks to its modern-day ancestor, the bird, he wants to hatch a dinosaur straight from a chicken egg.
It’s Horner’s vision, and McGill University paleontologist Hans Larsson is working to make it happen. With Horner’s encouragement, Larsson is experimenting with chicken embryos to create the creature Horner describes: a “chickenosaurus,” they call it. If he succeeds, Larsson will have made an animal with clawed hands, teeth, a long, dinosaurian tail and ancestral plumage, one that shares characteristics with “the dinosaur we know that’s closest to birds, little raptors like the velociraptor,” Horner says.
Their quest to build a dinosaur is taking them millions of years into the past, and forward again to the very edge of science, so cutting edge it sounds more like science fiction. Beyond the ethical questions that surround their work—or even practical questions, such as how and where such a creature would live—resurrecting a dinosaur sounds too far-fetched to be true. Yet both men insist they’re almost there. “I believe it will happen,” Larsson says. It’s just a question of when. If all goes according to plan, he adds, Horner will have his pet dinosaur within five years’ time.
Reached over the phone at the T.rex Discovery Centre in Eastend, Sask. (otherwise known as “Dino Country”), Larsson has been out in the field all week, digging for bones. As part of a three-week course he teaches in paleontological fieldwork, 15 students, mostly from McGill, spend their days prospecting through the badlands, excavating fossils with anything from “dental utensils to a pickaxe and shovel.” At night, they gather round a bonfire, sharing beers and stories. There’s much to tell: one student found a velociraptor claw; another got a Tyrannosaurus rex’s tooth. “We finished [digging out] a baby T. rex skull last week,” says Larsson, 38.
Compared to his lab work with chicken embryos, digging up dusty bones seems decidedly old school. Yet Larsson, one of the very few paleontologists who also works with embryos, insists they’re intimately linked—which brings him to Saskatchewan, a great place to look for fossils. The reason why dates back about 66 million years, when a meteor “the size of Montreal island” smashed down near Mexico’s Yucatán Peninsula, sparking forest fires, tsunamis, and sending up a giant dust cloud that spread throughout the atmosphere. “Seventy-five per cent of all species went extinct,” Larsson says. “Most life ceased.” Eventually, the debris settled, creating a clay layer that’s still visible at different locations across the planet, including in Saskatchewan, where it’s a “beautiful, one-cm-thick orange clay, packed through with shocked quartz and iridium.”
Because the baby T. rex skull was found near the clay layer, it was probably one of the last dinosaurs to live before the mass extinction. According to Larsson, a creature’s evolution over millions of years—which can be traced in fossils like the T. rex skull—provides valuable insight into the individual animal’s development over its lifetime. Likewise, a chicken’s progress from embryonic blob to feathered fowl says something about evolution, and maybe even how to reverse it.
It’s a driving idea behind evolutionary developmental biology, or “evo devo” for short. A relatively new field of science, evo devo was sparked by the startling discovery that most creatures share many of the same genes. Homeobox genes (or Hox genes), which ﬂick on during development and govern which body parts go where, were first found in fruit flies in the 1980s, says Sean Carroll, an evolutionary biologist at the University of Wisconsin-Madison. (Experiments to find Hox genes were straight out of a horror movie: scientists created insects with legs where their mouths should be.)
After pinpointing these master genes, researchers “looked around the animal kingdom, and were stunned and delighted to find them everywhere,” Carroll says. Indeed, we’ve got more in common with other species than most people realize. The DNA of a person and a chimpanzee, for example, are about 99 per cent identical—meaning that, in the six million years of evolution that divide us, less than one per cent of the three billion letters in the human genome have changed. Even the sea squirt, a tube-shaped creature that clings to underwater piers, shares about 80 per cent of our genes. “If you take snakes, frogs and birds, you’re really taking the same genes and using them in different ways,” Carroll says. Not only do we share genes with other animals; we share them with distant ancestors, too. Despite evolutionary change, many of our genes have been around for more than 500 million years, Carroll says.