by Matt Kaplan
Based on size alone, the average Tyrannosaurus rex was much more of a threat than the long-necked plant-eater known so well today. Yet add to it the fact that its mouth was loaded with pointed teeth the size of bananas, and the results are mind-boggling.
It is difficult to know for certain just how strong the bite of a Tyrannosaurus was, but comparisons with modern animals can give scientists a rough idea. Numerous bear and great cat species have jaws strong enough to crush a human head like a grape. With this in mind, T. rex would have been able to deal out a whole lot more damage had humans been around when it was alive.79
Aside from being fun for paleontologists, trying to work out how an ancient predator like Tyrannosaurus rex functioned is a great exercise for realizing just how small modern predators actually are. Perhaps more important, it is also an opportunity to recognize why dinosaurs have featured so prominently as monsters in stories since their identification by the scientist Sir Richard Owen in 1841. Even in the Victorian era, when Sir Richard was doing his work, he must have felt that they were frightening animals, because he chose to formally call them “deinos,” meaning “fearfully great,” and “sauros,” meaning “lizard.”
Dinosaurs have not changed since their discovery more than a century ago. Their bones are still just as big and their teeth just as sharp. Yet they have risen and fallen through the decades as monsters. There have been periods of intense interest along with some lulls. Why?
A lot of this likely has to do with believability. The waxing and waning of dinosaur popularity seem to follow trends that question whether they might “still be out there” or potentially be “resurrected.”80
Early books and films that featured dinosaurs as monsters always latched on to the idea of a “lost world” where dinosaurs had somehow evaded extinction. During the years when Arthur Conan Doyle wrote The Lost World and Jules Verne penned Journey to the Center of the Earth, there were still vast swaths of uncharted jungle on the planet. The idea of a land where great beasts still reigned supreme seemed both plausible and exhilarating. These mysterious and unexplored landscapes were perfect for early science-fiction writers to make use of because even the top scientists of the age admitted they had no idea what they expected to find there.
Yet the “lost world” genre of dinosaur monster stories lost its edge as Earth got better explored and it became obvious that the only species going unnoticed were the insects beneath the feet of native tribespeople.
Michael Crichton’s Jurassic Park dramatically changed the dinosaur monster genre by moving away from the historic “lost world” concept. Instead, Crichton, being well trained in the sciences, accepted dinosaurs as extinct and suggested that mankind had the ability to bring them back through modern genetics. Not only was this a new idea that the general public had not yet pondered, it also was one that researchers had not much considered either.
Resurrection attempted
The murky details of the science and theory behind Jurassic Park literally “resurrected” the beasts as monsters for a new generation. There were so many new unknowns in Crichton’s story that imaginations ran wild with the possibility of a terrible fiasco, like that seen in the theme park featured in the book, actually happening. Questions ran so deep that, in the wake of the book and film, people began to ponder the possibility that what Jurassic Park suggested with regard to dinosaur resurrection was actually possible.
All it would take was DNA stored in a drop of blood. In Jurassic Park, the premise is that mosquitoes collected blood from dinosaurs during the Jurassic and Cretaceous Periods, and some of these insects then became stuck in tree resin. Tree resin becomes hard over time and transforms into amber, which, according to the book, protects the insect and the dinosaur blood in its belly from decay and destruction.
Jurassic Park researchers drill into amber samples and draw out dinosaur blood from the encased insect to put together dinosaur DNA. The concept captivated imaginations because, at the time, the science seemed feasible.
The Natural History Museum in London, having no shortage of dinosaur bones, a large collection of fossilized insects in amber, and a team of capable paleontologists, became a focal point for inquiries from both the research community and patrons smitten with the concept of bringing back the dead. A team was assembled to start looking for dinosaur blood inside fossilized insects and, if found, to determine whether any genetic information on dinosaurs could be collected from it.
Upon setting out on this exploration, there was a great deal of optimism. DNA falls apart over time. Any exposure to bacteria, dramatic changes in temperature, or shifts in pressure can cause the tiny sequences of proteins making up DNA to decay, leaving the genetic code in useless tatters. Yet the idea that an amber shell might afford protection presented an exciting possibility for preservation.
The process of tree resin hardening into amber causes objects stuck in the sap to dehydrate. This is significant because water removal is well known to shield organic materials from decay. This is one reason why properly prepared Egyptian mummies buried in the desiccating sands of North Africa are still in such great condition after more than three thousand years. It was this desiccating property of amber that researchers were counting on to help DNA survive the sixty-to-eighty-million-year time capsule journey from the age of the dinosaurs to the modern world.
To add to the enthusiasm, in 1992, just two years after Jurassic Park was written, a laboratory in California reported extracting insect DNA from an ancient bee that had been encased in amber millions of years ago. Shortly thereafter, reports started cropping up describing the recovery of amber-preserved termite and beetle DNA as well. With so many cases of insect DNA being recovered, hopes were further raised that dinosaur DNA from insect blood meals would soon follow.
To start their work, the Natural History Museum team tried to repeat the Californian insect DNA capture research. They attempted to collect insect DNA from the same extinct bees stuck in amber that the Californians had worked with but were unable to do it. Using multiple extraction methods and repeating these with several different specimens got the team nowhere. And this process was intended to be just the first step. Really old, and therefore highly valuable, amber samples from the days of the dinosaurs were to be drilled into and sampled only if insects in younger amber yielded helpful data. With no useful information coming from the process, nobody could justify continuing the research and the project ended.
In theory, the failure to resurrect dinosaurs using the methods presented in Jurassic Park should once again have made dinosaurs less viable as monsters in modern media. Yet with the release of numerous film sequels, dinosaurs maintained their monster status. A reason for this probably lies in the fact that Jurassic Park used a multilayered approach to make its monsters believable. The resurrection technique was the most obvious, but there were actually two more.
Nature untamed
Chaos theory isn’t a big factor in the film, but the book develops the idea in great detail. Ian Malcolm, the mathematician in the story, relentlessly argues that biological systems, like those on display in the park, have tiny variables present in them that make their future behavior impossible to predict and, ultimately, impractical to control.
This talk of the natural world being unpredictable generates a perspective of nature that resonates with many real fears in society today. Hurricanes, tornadoes, earthquakes, and tsunamis wreak untold havoc and are extremely hard to predict. By their very nature they are chaotic and terrifying. Earthquake and tsunami detection research is advancing swiftly and, in the decades ahead, warnings of these disasters will become more common and precise. The same is true of extreme weather. Radar detection methods for predicting these dangerous events are improving, but it is still hard to work out exactly how hurricanes and tornadoes are going to behave.
Events like tornadoes and tsunamis, however, are not biological systems, and Malcolm’s argument about chaos theory and the dinosaurs in Jurassic Park is that biological
systems are uncontrollable by nature and therefore inherently threatening. Specifically, he says, “If there is one thing the history of evolution has taught us, it’s that life will not be contained. Life breaks free, expands to new territories, and crashes through barriers, painfully, maybe even dangerously.”
The chaos theory discussions are then combined with an image of dinosaurs not as extinct beasts with no real place on our planet but as living, breathing animals with a great many natural behaviors.
The attention to ecological detail runs throughout both the book and the film. The most striking example is the moment when Dennis Nedry, the corrupt computer programmer who purposely shuts down the electric fences in the park to smuggle out stolen dinosaur embryos, gets attacked.
Nedry is killed by a dinosaur, yet the mechanism for the attack is remarkably similar to the attack behaviors seen in modern predators. In both the film and the novel, the dinosaur, which is described as belonging to the genus Dilophosaurus, chirps like a bird while spitting venom from a distance to blind its prey before closing in for the kill.
There are no animals that actually spit venom, but there are a number of cobras that spray venom out of their fangs. While these real “spitting” snakes can (and do) blind other animals with their venom, they do not spray their venom for hunting; they do it as a defensive measure when threatened by larger animals. And just like the venom shown in the film, the venom sprayed by cobras does cause searing pain and blindness if it strikes animals (or people) in the eyes.
Maintaining a distance while spitting is equally well founded upon reality. Many predators go to great lengths to stay away from their prey when they attack. Komodo dragons make a single venomous bite and then back away so the toxins can do the killing for them.81 Venomous snakes do the same, allowing their venom time to take hold. The reason for these behaviors is thought to be that struggling prey can cause a lot of damage as they make their last attempts at survival. If a predator knows it has delivered a fatal or debilitating attack, there is no point in risking injury when dinner will be risk-free in just a short while.
The combination of such realistic traits in the dinosaurs along with the message that natural systems are totally unpredictable reinforces an image of the natural world as inherently dangerous to interfere with. In a sense, Jurassic Park makes Mother Nature the monster and the dinosaurs her tools for attack.
While snakes, as discussed throughout this book, certainly represent fears all on their own, a critical question to ask is whether there is any substance to Malcolm’s arguments. Is the natural world really so chaotic and fierce that any attempt to intervene is going to lead to disaster?
Even though humanity has not played God on the scale that the geneticists do in Jurassic Park, there has been a lot of ecological meddling in the past hundred years that is not really much different. One example stands out.
Shortly after colonists arrived in Australia, sugarcane started being grown in the warm and wet northeastern corner of the country. The environment was perfect for the crop and yields would have been incredibly lucrative—if it hadn’t been for the presence of a beetle. Unfortunately for the Australian farmers, the native cane beetle was fond of sugarcane. The adults of the species readily chewed up the plants while the larvae destroyed the roots.
In the early 1930s, the Australian government started considering the possibility of using nature against nature. Ideas were floated for bringing in a predator that could dramatically reduce cane beetle numbers and the government ultimately settled upon the cane toad from Hawaii, a carnivorous amphibian with a ravenous appetite for beetles.
The toads were introduced in 1935 and dismayed everyone when they were found to prefer insects other than cane beetles. Their taste for other insects was not a particularly large problem for the Australian environment, although it frustrated sugarcane farmers whose crops were still being destroyed by beetles. What proved disastrous was the fact that many Australian predators attacked the fat and slow-moving toads.
Cane toads have poison glands in their bodies, and unless they are eaten very carefully, their poison kills animals that consume them. Moreover, they were easy targets, which made matters worse since they were so readily hunted by Australia’s unique (and often rare) predatory marsupials, birds of prey, and snakes. The predators ate the toads and died in growing numbers. Having no successful enemies, the toads have today taken over the northeastern corner of Australia and continue to expand their territory. Native predator populations in the region respond by dwindling. Australians hunt the toads aggressively and scientists are working on ways to interfere with toad fertility. A solution may arise in the decades ahead, but there is no denying that playing God and installing the toads in the first place has created an ecological nightmare and cost Australia dearly.
In the Grand Canyon, human meddling with the environment has caused similar damage. Dams have been on the Colorado River for nearly a century. However, there were no dams upstream of the Grand Canyon until 1963, when the Glen Canyon Dam was built. At the time, the idea of damming the river above the canyon didn’t alarm anyone: Dams were popular, and cheap, clean hydroelectricity seemed like a good thing.
By the 1970s, serious long-term effects of the Glen Canyon Dam were becoming apparent. Downstream from the dam, the beaches that river rafters were used to camping on had eroded to half their original size and the National Park Service noticed that numerous native fish and animal species were vanishing.
Extensive analysis of the Glen Canyon Dam and many other dams around the world revealed that when dams slow water flow, they also disrupt the movement of sediment that the water is carrying. The principle behind this effect is relatively simple. When water moves slowly over bits of sediment on the river bottom, the force of the water might make the sediment roll along the bottom, but unless the sediment is very fine, like mud, it won’t get picked up. When water moves quickly, however, the situation changes, and even relatively large grains of sediment can be carried away by turbulent water flow. In raging floods, small rocks and even boulders can be swept away.
Geologists realized that in the reservoir behind the dam, water was dropping just about all the sediment it was carrying. Since the water had been unmoving for quite some time, when it was ultimately released past turbines, it carried little sediment and came out the other side of the dam crystal clear. This was a problem for fish downstream that depended upon sandy coves and rocky habitats to hide in, but, like the cane toad situation in Australia, it was the unintended consequences of introducing a foreign species that proved disastrous.
Humpback chub, a rare species of fish unique to the Grand Canyon, were not deemed impressive enough to interest fishermen. To compensate for this, the Colorado River was seeded with trout eggs and a population was enthusiastically nurtured to support fishing tourism.
Trout are voracious clear-water predators that eat other fish. Humpback chub, in contrast, depend upon cloudy water to hide from danger. By building the dam and introducing new predators, humans made it easy for trout to spot and eat humpback chub. Today the chub survive in just a few of the small undammed streams feeding into the Colorado River. Whether they will survive in the wild for very much longer is anyone’s guess, but they are now classified as just one step away from extinct.
To manage all of these problems associated with the Grand Canyon, the U.S. Geological Survey, in collaboration with numerous federal agencies, has taken something of a “nuclear” approach and, on several occasions, fully opened the Glen Canyon Dam floodgates immediately after heavy rains to bring sediment down cliffs and into streams to maximize the sediment’s spread through the Grand Canyon. A lot of questions are being raised about the effectiveness of this approach, but the fact that such desperate measures are being taken hints at the severity of the problems created by a reprehensible lack of foresight.
With these two tales of outstandingly bad environmental management in mind, Ian Malcolm’s argument of nature being an uncontrollabl
e force seems accurate. Yet as severe as these two ecological catastrophes are, humanity has not always left the natural world mangled.
Real resurrection
Yellowstone National Park in northwestern Wyoming is home to a great diversity of animals. Visiting the park is very much like taking a safari, with a drive through the Yellowstone area rarely avoiding a traffic jam created by bison, elk, moose, or bighorn sheep that have no appreciation for roads or traffic.82 Tourists often come away with the impression they have seen one of the few truly pristine wild places left in the world. Rather remarkably, they are wrong.
The story begins with pack rats, little rodents that often build their homes in rocky crevices. To construct their nests, they collect anything and everything from their habitat that piques their interest. In the modern day, this unfortunately means they frequently pick up shards of glass, bottle caps, and other bits of junk, but long before humans made a mess of things, they collected feathers, plant material, and bone. The pack rats then brought back their findings and urinated on them. Bizarre as it sounds, their urine binds their odd collection together into something of a nest.
Paleontologists have long been interested in pack rat nests, or middens, as they are called, because pack rats are nonmigratory animals that stick with the same nest location for many generations. Each new pack rat brings in new collected material, dumps it on top of old material, and solidifies it into place by urinating all over everything. Indeed, in the past few decades, paleontologists realized that some middens could literally be thousands of years old and that they represented a vast store of preserved bones unwittingly collected by pack rats. They were like little paleontological gold mines.
In the early 1990s, as paleontologists led by Elizabeth Hadly at Stanford University were surging forward with their analysis of small bones found in Yellowstone middens, ecologists were asking serious questions about the park’s ecosystem.