By Mary Halton Science reporter, BBC News
Image copyright Universal/Tippett Studio
- In 1993, Steven Spielberg's film Jurassic Park defined dinosaurs for an entire generation.
- It has been credited with inspiring a new era of palaeontology research.
- But how much science was built into Jurassic Park, and do we now know more about its dinosaurs?
- As its 25th anniversary approaches, visual effects specialist Phil Tippett and palaeontologist Steve Brusatte look back at the making of the film, and what we've learned since.
So, first of all, what did Jurassic Park get wrong? It started off by inheriting some complications from Michael Crichton's novel, on which the film was based.
- “I guess Cretaceous Park never had that same ring to it,” laughs Brusatte.
- “Most of the dinosaurs are Cretaceous in age, that's true.”
- The Cretaceous period, which followed on from the Jurassic, was home to many of the dinosaurs which feature heavily in the film, including Tyrannosaurus rex, Velociraptor and Triceratops.
Image copyright Universal/Tippett Studio
The idea of recreating dinosaurs from preserved DNA also proves problematic.
“In order to clone a dinosaur you would need the whole genome, and nobody's ever even found a little bit of dinosaur DNA,” says Brusatte. “So we're talking about something that's pretty difficult, if not impossible.”
Quibbling about such details may seem inconsequential. But for a film that proudly treats its prehistoric cast of creatures as characters rather than monsters, Jurassic Park treads a fine line between scientific accuracy and cinematic fantasy.
How to build a dinosaur
- Case in point – building an animal that no human being has ever seen, and making it as realistic as possible.
- At the time, Jurassic Park was groundbreaking in its use of computer animation in tandem with animatronics.
- Stop motion expert Phil Tippett, who had previously worked on Star Wars, was brought in as dinosaur supervisor, a role which would later earn him fame as an internet meme.
Image copyright Tippett Studio Image caption Tippett had already directed a stop motion dinosaur short called Prehistoric Beast
In addition to the film's consulting palaeontologist Jack Horner, Tippett also had a great deal of dinosaur knowledge.
“[I] bought every book that came out on dinosaurs. So I was pretty well in tune with what the state of the science was at that point in time,” he told the BBC.
Tippett remembers having to rein in some of the descriptions from the novel.
“Crichton would have a Tyrannosaurus
Jurassic World: Can We Really Resurrect a Dinosaur?
The following essay is reprinted with permission from The Conversation, an online publication covering the latest research.
This summer, the fifth installment of the Jurassic Park franchise will be on the big screen, reinforcing a love of dinosaurs that has been with many of us since childhood. There is something awe inspiring about the biggest, fiercest, and “deadest” creatures that have ever walked the planet. But the films have had an additional benefit—they have sparked an interest in dinosaur DNA.
The “Mr DNA” sequence in the original movie is a great piece of science communication and the concept of extracting DNA from the bodies of “dino” blood-engorged mosquitoes is an outstanding piece of fiction. It is, however, just fiction.
Jurassic Park’s solution for resurrecting dinosaurs.
Quite by chance, we’ve recently identified the overall genomic structureof dinosaurs. The genomic structure is the way that genes are arranged on chromosomes in each species. Although individual animals from the same species will have a different DNA sequence, the overall genomic structure is species-specific.
Can we create a real Jurassic Park?
Sure, “Jurassic Park” is ultimately a cautionary tale about out-of-control genetic science (and equally out-of-control prehistoric carnivores), but let's face it: You still wish it was real.
You yearn to peer out the window of an SUV and watch a Tyrannosaurus rex lumber into a clearing.
Deep inside you, there's a hole that can only be filled by pointing a Canon PowerShot at a diplodocus.
Unfortunately, wanting it doesn't make it real.
Remember Michael Crichton's explanation about how prehistoric mosquitoes trapped in amber (fossilized tree resin) have dinosaur blood in their bellies? All you have to do is tap them, right? Yet as elegant as that sounds, the premise presented a few problems. For starters, even DNA preserved in amber degrades over several million years. If fragments of dinosaur DNA survived the passage of time, they might mix with insect DNA during extraction.
The scientists of “Jurassic Park” get around the problem of missing DNA by filling in the missing pieces with frog DNA. That might fill a plot hole, but the gaps in a dinosaur's genome are a different matter. Even if frog DNA were the best choice to fill the gaps, the chances of actually pulling it off are astronomical.
But let's say you actually lucked out and reconstructed the entire dino genome, and the chances of that are seriously slim. At this point, you'd have to come up with a way to transform the DNA into chromosomes.
If you pulled that off, you'd have to find a place to implant them. The ideal place would be a living dinosaur egg, which we don't have.
At a bare minimum, vertebrates require the egg and cytoplasm of a closely related species, and no living creature on Earth fits that description.
Science Behind the Fiction: Are we any closer to Jurassic Park actually being possible?
Most of us have an almost innate fascination with extinct animals. Pick a kid in your life and there's a good chance they'll happily spend an hour telling you all about their favorite dinosaurs.
There's something enticing and a little frustrating in the idea that there were once fantastic creatures roaming the earth that disappeared — either due to environmental factors or human interference — before you arrived on the scene.
The notion of reviving extinct species was popularized by Michael Crichton's 1990 novel, and subsequent film adaptation, Jurassic Park.
In that apocryphal tale, John Hammond acquires dinosaur DNA from the guts of mosquitoes trapped for millions of years in amber.
Using modern species to fill in the genetic gaps, Hammond's scientists revive a number of extinct dinosaur and pterosaur species in an effort to build a theme park.
We all know how well that effort panned out. It's a hallmark of Crichton's work for cutting-edge fictional technologies to clash with human error, ignorance, and hubris to catastrophic ends. Such it is with Jurassic Park.
At the time, the technologies posited in Crichton's novel were complete fantasy. Genetics was still a burgeoning field of biology, just getting its feet on the ground. There were promises of what the field might be able to accomplish in the future with new tools, but none of that had materialized yet.
The Human Genome Project launched the same year as Crichton's novel and was completed in 2003, 13 years later. Since then, technology in the field has improved dramatically, with genome sequencing time frames now being measured in days rather than years.
How scientists actually could bring dinosaurs back to life
On Jan. 6, 2000, a wild mountain goat named Celia was crushed to death by a falling tree on the cliffs of the Spanish Pyrenees — thus beginning her march into history.
Celia was a bucardo — a specific species of wild goat — and, as it happens, the final one.
But a group of Spanish scientists had other ideas. Ten months earlier they had taken a sample of Celia’s tissue, in the hopes of bringing her species back from extinction.
If it worked, notes science journalist Helen Pilcher in her new book “Bring Back the King: The New Science of De-extinction” (Bloomsbury Sigma), it “would mark a defining moment in the history of the Earth; an end to the finality of extinction.”
“Bring Back the King: The New Science of De-extinction” by Helen Pilcher (Bloomsbury Sigma)
Two years later, “cells with Celia’s DNA were injected into goat eggs that had been stripped of their own genetic material. After a brief electrical jolt, the eggs then began to divide.”
The embryos were implanted into the wombs of “surrogate mother goats,” and while most of the pregnancies failed, one did not.
History was made on July 30, 2003, when one of Celia’s clones was born, marking the first time a species ever came back from extinction. Sadly, her health did not hold up. Her lungs had been “grossly deformed” and she died seven minutes later — marking the first time ever a species had gone extinct twice.
- Many of us were introduced to the concept of “de-extinction” by the movie “Jurassic Park,” which resurrected the dinosaurs to horrific ends.
- But the idea behind the film wasn’t the wild invention of a Hollywood screenwriter.
- Pilcher writes that in the 1980s, John Tkach, founder of a “secretive cabal of scientists and clinicians in Bozeman, Montana” calling themselves the Extinct DNA Study Group, posed an intriguing thought experiment.
“What if, many millions of years ago, there had been a hungry mosquito that dined on a dinosaur then became trapped in amber, with its last supper still inside its stomach. If one could recover a dinosaur blood cell from inside that mosquito and then transplant it into an egg that had had its own DNA removed,” it might be possible to “grow a dinosaur.”
This theory might have been far-fetched, but it wasn’t totally crazy.
Entomologist George Poinar from the University of California at Berkeley spent his career studying million-year-old insects preserved inside tree resin that had hardened into amber.
Usually they were intact on the outside but the insides were “a disappointing mess,” but in 1980, he came across a fly that “defied expectation,” with cells still intact after 40 million years. This was exactly what Tkach had theorized about.
A modern living dinosaur is not a fantasy.
Poinar’s findings, once published, excited the scientific community, including “a tall, gangly man” who visited his lab to ask questions about “bringing back life forms in amber.
” Poinar thought nothing of it until years later, when he was informed that he’d been thanked in the back of a new book, soon to be a movie, called “Jurassic Park.
” The book’s author, Michael Crichton, had been his tall, gangly visitor and “used [his visit] as the scientific basis for his novel.”
So where does the effort to de-extinct the dinosaurs sit today, decades later?
“A modern living dinosaur is not a fantasy,” writes Pilcher in her book.
But while there are respectable scientists who believe it can be done, she also makes it clear that we shouldn’t hold our breath. After all, finding the raw material to create a dinosaur is a tremendous challenge, to say the least.
“To de-extinct an animal, you need a source of that animal’s DNA,” writes Pilcher. “But all we have for dinosaurs are their remains, cast in stone.”
In 2000, a bucardo goat named Ceila died in Spain as the last of a species. Three years later scientists brought her back to life.Courtesy Government of Aragon
- Much of our information on dinosaurs comes from fossils, and “dogma has it that when fossilization is complete, any organic trace of the animal is gone,” Pilcher writes.
- Even so, starting in 1992, paleontologist Mary Schweitzer made a series of discoveries determining, among other things, that dinosaur fossils “contain molecules that are found in red blood cells,” and that certain types of dinosaur tissue could “survive fossilization.”
- Continuing her work, she determined that protein molecules had survived as well, leading the Guardian newspaper to write that her findings “hint at the tantalizing prospect that scientists may one day be able to emulate ‘Jurassic Park’ by cloning a dinosaur.”
- Still, this is just a first step in uncovering enough dinosaur material to build them anew.
Creating dinosaurs: why Jurassic World could never work
When the first Jurassic Park movie hit the silver screens in 1993, I cried. Never before had dinosaurs, those magnificent creatures of bygone days, been brought to life so realistically. It was a palaeontologist’s dream come true.
Jurassic Park and its sequels were huge hits, and dinophiles around the world are now anxiously awaiting the release of the next instalment, Jurassic World on June 4 this year.
These films give an impression that science might be really be capable of bringing back a living dinosaur. The latest outing goes even further than the previous films, where only dinosaurs that once existed were recreated. Jurassic World is about the “genetically modified hybrid” dinosaurs.
But is this all really possible?
The answer is a kind of “yes”, but not in the same way that the Jurassic Park movies might suggest.
Can we ever find and use dinosaur DNA?
DNA is the building block of life. It’s the veritable blueprint for how cells divide, multiply and eventually build an organism’s body plan. We can clone genetically identical organisms from the DNA of a parent organism, including mammals such as Dolly the sheep.
When an organism dies, the soft tissues, including the DNA, break down and eventually are destroyed. But in some cases, parts of dead animals and plants are buried and preserved as fossils. And in very rare cases soft tissues of fossils can be preserved.
In some cases parts of the DNA can be extracted from well-preserved fossils, as in the recent case of two extinct Australian fossil kangaroos, whose DNA was dated between 40,000 to 50,000 years old.
In these cases only small sections of the extremely long DNA molecule are ever found. Although these short segments of fossil DNA can often give us valuable information about the relationships of the extinct animal to its living relatives, they are far too fragmentary to ever give us the full picture of the animal’s genome.
For example, the human genome has 23 chromosomes composed of 3.2 billion base pairs of molecules. Reconstructing the full set of chromosomes is thus an impossible task if using just a few short segments of one chromosome as reconstructed from a fossil.
In their book The Science of Jurassic Park and The Lost World, Rob Desalle and David Lindley describe how the process shown in the movies for reviving a dinosaur from fragments of fossil DNA is fundamentally flawed.
Could a 90 million year old fossil mosquito preserved in amber contain traces of its last meal’s DNA? Wikimedia/Brocken Inaglory, CC BY-SA
- The method used by the fictional genetics company, Ingen, involved finding dinosaur DNA still inside fossilised mosquitoes preserved intact in amber, which is sap that seeps from trees and often covers unwary insects.