We asked Riley Black, a science writer specializing in evolution, paleontology and natural history, to weigh in on the film’s basic premise — that dinosaurs were cloned using DNA taken from mosquitoes.
Time is a critical factor.
The last of the non-avian dinosaurs – undeniably fearsome
that haunt museum halls and our dreams – they became extinct 66 million years ago. It’s so far away from us that we can’t even fathom how long it’s been, and we’ve lost any chance we had of cloning dinosaurs in the relatively short time since the late Cretaceous mass extinction.
This isn’t the dinosaur mix you’re looking for…
You may have heard that paleontologist Mary Schweitzer and colleagues recovered some soft-tissue remains from the Cretaceous dinosaur Tyrannosaurus and the hadrosaur Brachylophosaurus. These claims have been controversial, but cannot be dismissed. Schweitzer and others have built a stunning argument that in exceptional cases, fragments of the original dinosaur protein may have survived to the present day. But that’s not what we need to clone a dinosaur. The starting point of any dinosaur resurrection exercise is DNA. Unfortunately for paleo geeks like myself, DNA has a relatively short half-life. There is almost no chance of ever recovering the genetic material of the dinosaurs.
Looking at the bones of recently extinct bird-like dinosaurs—specifically, the 8,000- to 600-year-old bones of giant flightless birds called moas that once walked New Zealand—the geneticists calculated that DNA has a half-life of 521 years. That’s longer than researchers expected, but nowhere near long enough to allow us to ever get DNA from a Tyrannosaurus or Triceratops (much less much older dinosaurs like Brachiosaurus and Dilophosaurus). Even under ideal conditions where the bones would remain dry and chilled at -5 degrees Celsius or below, the creature’s entire genome would have been wiped out within 6.8 million years, or about 59 million years less than the last non-avian dinosaurs.
Parasaurolophus puzzle
Any ancient dinosaur DNA would show up in tiny and gray, just like the Ice Age mammoths, Neanderthals, giant sloths, and saber-toothed cats that provided the genetic minutiae. The trick is to identify those parts and figure out where they belong in the animal’s complete genome. It requires a baseline derived from a close relative – modern Asian elephants work for mammoths, and our own genome for Neanderthals.
But living bird dinosaurs are so far away Pachicephalosaurus and that their utility in revealing the genome arrangement of non-avian dinosaurs would be quite limited. And that’s not to mention pseudogenes and non-functional parts of the genome. We haven’t even fully sequenced the genome of our own species—we’re still at about 99 percent of the functional part—so we’re pretty far from completely reconstructing an extinct genome.
Raptor by any other name
So a Velociraptor or Tyrannosaurus genome would not be a feat of resurrection, but of reinvention. Even if it were possible to obtain dinosaur DNA, we would have to reverse-engineer dinosaur genomes according to our best possible estimates of their anatomy and behavior. There are more obstacles. Creating a complete DNA profile gets you nowhere if those genetic cues can’t be translated into a viable embryo that will grow to maturity. It is understandable that Michael Crichton and the film adaptations of his work completely obscured this point, especially since researchers cannot clone birds.
It’s easy enough to say – We’ll stick an artificial nucleus in an ostrich egg and the rest will take care of itself, but that ignores the intrinsically biological interactions that actually make up a living, growing organism. Since birds committed the growth of their offspring outside the body, there may not even be a way to successfully clone a bird, so there would be no method by which we could bring back the dinosaurs even if we had all the necessary raw materials.
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