Medusa's Gaze and Vampire's Bite: The Science of Monsters
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Elk seemed to exist in greater numbers in Yellowstone than in many other wilderness areas in northern North America. In addition to this, coyotes, which traditionally function as scavengers in most ecosystems, were found hunting larger animals than those they would usually pursue and were behaving more aggressively than coyotes in other regions. Some researchers suggested that this behavior was due to the absence of wolves, another large predator, which until 1923 had been living in Yellowstone but were wiped out by deliberate hunting.
Controversy raged over this issue. Many argued that wolves had artificially been in the Yellowstone area only during the late 1800s and early 1900s after being pushed out of lower-elevation areas where Europeans were expanding their settlements in the Great Plains. Yet Hadly’s team disproved this theory.
Hadly found wolf bones that were thousands of years old in pack rat middens, proving that wolves had been in the Yellowstone area long before humans ever entered the picture. Her findings led ecologists to realize that wolves really were supposed to be living in the area; human activity had not artificially shoved them into the region. A recent local wolf extinction, caused by people, was the reason for coyotes functioning as predators and for the overly large populations of elk. With this in mind, the solution seemed simple: Reintroduce wolves to the park. Ultimately, to the chagrin of many ranchers and farmers in the area, they were returned to Yellowstone in 1995. Like Jurassic Park, animals driven to extinction had been brought back to the land they once roamed.
In the 1970s, Crichton’s description of an uncontrollable, dangerous natural world was a reasonable conjecture. But scientists in the fields of ecology and conservation biology are getting better at making models of the systems they are thinking of tampering with. They also are studying past ecological activity by looking at fossils of the same animal over time so they can more accurately predict the effects of their proposed actions. This improvement in modeling is comforting, since global warming will require a great deal of human intervention if the world’s diversity is going to remain intact as Earth continues to warm up. Indeed, governments are hiring paleontologists to analyze fossil ecosystems that existed during earlier times of global warming in order to work out how modern ecosystems are going to alter as climate changes.
In theory, as such environmental tinkering improves, the argument made by Ian Malcolm in Jurassic Park should weaken. This, in combination with the fact that dinosaurs cannot be resurrected using the methods outlined in the film, should make these creatures wane as monsters in popular culture during the decades ahead.
Yet resurrection of ancient beasts is not entirely out of the question. Hadly’s team was able to find intact DNA in fossils thousands of years old in North and South American ecosystems. Hadly has no interest in even considering the resurrection of extinct beasts, but there are more than a few groups keen to make a lot of money by bringing back something like a woolly mammoth. The idea has led to interest from both the research community and the general public. To some it just sounds exciting; to others it is a great challenge to be tackled. To pursue it, two avenues are being explored.
Some researchers are looking for germ cells, like sperm and eggs, in mammoths that were covered in ice in Siberia thousands of years ago. No research teams have succeeded in finding any such cells intact, but even if they were to do so, they would then need to use an elephant egg cell or sperm cell to partner with whichever mammoth germ cell they found to create a few “half mammoths.” These half mammoths would then need to be intensively inbred with one another until a “near mammoth” that was only 1 percent elephant was created.
The other option for creating a mammoth involves collecting standard DNA from a frozen fossil specimen and injecting it into an elephant egg cell that has had its own DNA removed. This was the process used to create Dolly, the cloned sheep. No mammoth DNA of good enough quality has been found to make such a process viable, but researchers keep finding better and better samples, so there is a chance that such a project might one day prove successful.
Yet hope for resurrecting species is misguided. Not only is our planet in the exactly wrong climatic period to sustain these ice age beasts, vast resources are going to be required to make a project like this work, resources that could be used to save the many critically endangered animals on the planet. “How can we justify ‘bringing back’ animals when we are at a loss to preserve the diversity on the planet today?” asks Hadly.
A resurrected mammoth would inevitably end up in a zoo, since no natural habitat exists for such a creature. In contrast, if the carnivorous marsupial the Tasmanian devil goes extinct in the decades ahead—which is likely given that devil populations are dying out from a poorly understood cancer that gives them horrendous facial tumors—resurrection technology could much more sensibly be used to help their populations remain in their environment and survive the epidemic. There are even reasonable arguments for potentially resurrecting very recently extinct animals like the passenger pigeon and the Tasmanian tiger, another carnivorous marsupial that died out in the 1930s. These animals went extinct as a direct result of recent human activity, and their habitats are still more or less intact. Indeed, their habitats, similar to that of Yellowstone, have been thrown out of whack by their absence. From the perspective of maintaining ecological balance, pouring resources into resurrecting some animals makes sense to set things right again, but only after all available resources are expended to stem the tide of destruction that is wiping out ever more species. It is, after all, much easier (not to mention cheaper) to keep an extremely rare species alive than to attempt recovering one from beyond the grave.
With moral arguments standing strong against resurrecting even mammoths, and the possibility of ever using DNA to resurrect something as old as a dinosaur looking highly unlikely, will dinosaurs forever fade from popular view as monsters? This seems doubtful.
Where there’s a will…
You can’t keep a good scientist down, and among paleontologists this tends to be particularly true. There are numerous paleontologists who would love to see a dinosaur brought back to life, and even though the methods of resurrection presented in Jurassic Park have failed with dinosaurs, there may be another way.
Traditionally, when paleontologists have looked at the bodies of animals and asked, “Now how the heck did that evolve?” they have gone looking for the fossils of the given animal’s ancestors. A classic example is the bird wing. Paleontologists know that birds evolved from animals that did not have wings initially, but the evolutionary pathway that was followed toward flight is one we do not understand very well. Did bird ancestors jump around in trees? Did they glide first and develop powered flight later? Or were feathers selected for by evolution simply because they looked sexy (to other birds) and meant that bird ancestors with more colorful feathers could mate more often?
Researchers have spent ages trying to solve the evolutionary puzzle of flight by searching extensively for fossils of very early birds and then analyzing the bones to better understand how ancient wings or, in some cases “proto-wings,” would have worked. The work is truly astounding, and a lot of theories for how flight might have evolved have been put forth.83
Intriguingly, a research lab at McGill University in Montreal led by Hans Larsson is taking the study of great evolutionary transitions, like flight, in a rather new and extraordinary direction. The lab is intensively analyzing the way modern animals grow from their state of being a single cell, into masses of cells, and then on to embryos, fetuses, babies, and ultimately adults.
Why is studying babies useful when studying evolution? Are they not two totally different processes? Well, lurking in the genes of animals are shadows of their evolutionary past. These genetic shadows usually remain shadows as the animals develop from embryos to adults, but very rarely they can become quite real in the form of atavisms (remember those from way back in “Beastly Blends”?). Humans can sometimes be born with a tail and snakes and dolphins are sometimes born w
ith the limbs that their ancestors had. What all this means is that many of the genes of the past are present in the body, but they just are not activated most of the time.
In theory, this means that instead of studying fossils to learn how a bird wing evolved, researchers can also study the embryos of birds, tweak their genes, and see for themselves which ones control the formation of wing bones from limbs. This is the sort of work Larsson and his team are doing and, as it happens, this is also the kind of work that may ultimately present another viable pathway for resurrecting dinosaurs.
By looking carefully at bird embryos and identifying the biochemical and genetic processes controlling certain parts of the bird’s development, researchers are finding it possible to deactivate feathers from forming on certain parts of the bird’s body, activate scale formation in certain areas, lengthen the tail, and, perhaps most dramatically, cause the bird to grow sharp teeth.
Now consider this: If a bird were to have its feathers removed, its skin covered with scales, its tail elongated, and its mouth littered with pointed teeth, what would we have?84
The number of genetic manipulations needed to actually create a dinosaur from a bird embryo is enormous, and it is going to be some time before anything viable is produced. But unlike finding usable dinosaur DNA in amber, there has not been much argument about whether the mechanisms for this procedure are sound.
Make no mistake, something with razor-sharp teeth is going to be hatched from a bird egg in the next hundred years. Let’s just hope it doesn’t get loose in the lab and start spitting venom.
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79 T. rex is thought to have had a bite force of roughly 3 tons; by comparison, the largest great white sharks have a bite force of around 2 tons. Lions tend to have a maximum of 0.6 tons. Puny.
80 Strictly speaking, they are still out there, they just have feathers and eat bread crumbs in your local park—but most folks don’t think about pigeons and their kin as dinosaurs, even though, from an evolutionary perspective, they are.
81 Komodo dragons were long thought to have toxic saliva that caused lethal raging infections in the animals they bit, but recent studies show that they have venom glands in their mouths.
82 Strictly speaking, this might not actually be true. A couple of recent studies suggest that large herbivorous animals are migrating toward roads to give birth specifically because they seem to realize the predators that eat their young (like grizzly bears) tend to avoid areas where humans are present in large numbers, like roads. Gives the term “human shield” a whole new meaning.
83 The theory that gliding led to powered flight looks to be utterly impossible. All early bird wings seem to have been fully mobile and flapping from the start, whereas modern gliding animals, like flying squirrels and flying snakes (yes, there are such things), just fling themselves outward from trees without moving their “wings” at all. Some nice work with bats is hinting that dropping down from branches followed by fluttering to help control the end of the drop might be how flapping flight actually evolved, but more work needs to be done.
84 Okay, yes, a really ugly chicken, but you get the idea.
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10
Extraterrestrial Threat—Aliens
“My mommy always said there were no monsters—no real ones—but there are.”
—Rebecca “Newt” Jorden, Aliens
On the night of September 19, 1961, while driving south along Route 3 in New Hampshire, two people had a close encounter with something they described as resembling a large illuminated cigar-shaped object. They woke up later with no memory of the time that had passed and found signs on their clothes and car that led them to conclude they had been abducted and studied.
Whether this was the first reported alien abduction in human history or simply the first to get wide media attention is up for debate. What is not debatable is that these were fairly normal individuals. Neither had a history of being an alien enthusiast or showed signs of being mentally unhinged when they were later psychologically evaluated. For these reasons, their story was taken seriously and the location where the abduction is said to have occurred was commemorated by the state of New Hampshire with a plaque describing the event.
Countless tales of abductions and bizarre sightings followed. Some of these reports came from people who were alien fanatics, but some were not. Yet there is something notable about the hysteria: All of it was taking place as the United States and the Soviet Union were racing into outer space. Just as the so-called space race was weighing heavily on the minds of millions, aliens were suddenly coming for a visit. The nature and timing of the alien abduction reports lend credence to the skeptics. Why were earlier abductions not reported to the press? If aliens can come to Earth with glowing cigar-shaped spacecraft, why does all the space-scanning technology that has been developed during the past decades never detect them? It is an enigma.
Regardless of all the questions, it is intriguing to note that alien life is now taken more seriously by the research community than ever before. Whether or not aliens are “somewhere out there” is a question that, scientifically, is not up for much argument anymore. In 1996, it was reported that evidence of microfossils of bacterial life were found in a Martian meteorite. The meteorite had once been part of the surface of Mars, and after the red planet was hit by another large meteor, it got blown off, and ultimately, after hurtling through space, found its way into Earth’s orbit. Scientists found an odd mix of chemicals and minerals in the meteorite that looked a lot like chemicals and minerals sometimes left behind by simple microscopic organisms on Earth. This led the researchers to propose they had found evidence of life having once existed on Mars.
It might be easy to dismiss this work as the enthusiasm of some fringe researchers and perhaps a bit of lax publishing by a second-or third-tier academic journal with poor peer review processes, but the report was written by a team at NASA and published in the journal Science. This does not, of course, indicate that the findings were bulletproof. NASA makes mistakes and Science does sometimes publish articles that are later proved to be dead wrong. Dozens of articles followed the 1996 report, poking at potential flaws and questioning the scientists’ interpretations. This is the nature of modern research, and it will take time before the greater scientific community concludes with certainty that these microfossils are actually evidence of life having once existed—or not—on Mars. Even so, scientific consensus is probably not as far off as it may seem. Evidence is mounting that liquid water was once present on Mars, indicating that conditions may have existed that could have allowed for the evolution of simple life. Furthermore, as astronomers explore the cosmos with advanced telescope technology, it is becoming apparent that there are other planets in distant locations of a similar size to Earth and a similar distance from a sun. This hints there are places where conditions much like those found on Earth can exist, and if this is true, the logic runs that life has probably taken root. It is on the question of what alien life is actually like where the wheels come off the proverbial wagon.
The shape of the unknown
In theory, if life were to evolve on a planet with conditions like those on Earth, it should follow evolutionary pathways similar to those that have happened here. Even so, some of evolution’s pivotal moments have taken place after chance events. Volcanic eruptions, extreme glaciations, severe sea level changes, and meteorite impacts are just a few of the phenomena that have affected the course of evolution. This raises the fascinating question of whether life on Earth would be substantially different today if only a few major chance events took place at different times or did not take place at all.
As an example, consider the concept of snowball Earth. Millions of years before the rise of multicellular life, geologists theorize that the planet became extremely cold, with glaciers of enormous size covering the tropics. Some experts argue that the freezing was extreme enough to create ice sheets over the entire ocean. Others maintain that the cold was not quite so sever
e and that ice did not cover absolutely everything.85 But most everyone agrees there were at least some glaciers in the tropics near the equator.
Glaciers look solid and unmoving, but they are actually rivers of ice flowing very slowly. As they move, they break pieces of sediment and rock from the land and carry these off. Many glaciers eventually flow onto the ocean, where they float out over the water. When they eventually melt, they drop the rocks they are carrying, which land among ocean sediments that are often distinctly different from them. Known as ice rafted debris, these “drop stones” provide crucial evidence of major glaciations having once taken place.
Patterns of ice rafted debris found in ocean sediments hint that there was not just one cold period, but many. The planet, for reasons that are still not well understood, seems to have gone from very warm to very cold numerous times just before multicellular life started to evolve. Some paleontologists argue that the timing of complex life’s evolution closely following these climate oscillations was not a coincidence.
When life gets isolated into small and enclosed environments, selective pressures are altered. This is why birds that find their way to places without land predators often, over time, lose the ability to fly and why animals that end up on isolated islands look so different from their mainland kin. These evolutionary effects have led to the idea that extreme glaciations isolated simple life into tiny communities for long periods of time, allowed evolution to do some very strange things since selective pressures in these isolated environments were unique, and then released the organisms that evolved in these communities to interact and compete globally for a while before isolating them again in another extreme glaciation. This scenario may have functioned as a crucible of evolution and proved essential to the development of multicellular life.