Medusa's Gaze and Vampire's Bite: The Science of Monsters (29 page)

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.

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.
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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 with 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?
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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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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.

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 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.

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 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.

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 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.

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 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.

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 Okay, yes, a really ugly chicken, but you get the idea.

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.

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 severe and that ice did not cover absolutely everything.
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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.

But what if these extreme cold and hot episodes never happened? Would life have ever moved on from being single-celled? Would it have moved in a very different direction? The same sorts of questions are asked about the meteorite impact and other catastrophic events that struck the planet sixty-six million years ago. If
Tyrannosaurus
and
Triceratops
had not died out, would mammals have ever stepped into the evolutionary spotlight? Would reptiles still rule Earth?

For all of these reasons, alien life from a planet identical to Earth could be remarkably different from life as we know it today simply due to the fact that chance events would have likely shaped biology differently. Trying to work out what life was like on a planet with subtly different characteristics really makes things interesting. Consider a planet very much like Earth but with reduced gravity. Flying and jumping would probably evolve more easily, skeletons would not need to be as robust since weight would be reduced, and winds would throw much more debris into the air, possibly leading to the evolution of visual organs quite different from the eyes used on Earth. Gravity is just a minor change, but the evolutionary effects would be major. To put it simply, Earth-like planets are probably out there, they probably sustain life, and there is a good chance that any complex life found on them is vastly different from the life found on Earth. The mysteries that surround alien life are as vast as the blackness of space itself. It is this ponderous infinity from which terror takes shape.