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05/09/2002
World-Ending Scenarios
In my opinion, we humans need to quit all this stupid fighting
among ourselves and concentrate on things that threaten our very
existence. My favorite threat is the possibility of an asteroid or
comet slamming into our planet, taking out the human race, as
happened some 65 million years ago with the dinosaurs. My
concern over our future was heightened by couple of articles in
Discover magazine. I''m ashamed to admit that I found one of
the articles in my previously untouched 20th anniversary issue of
Discover magazine dated October 2000. I''m just a tad behind!
The article, by Corey S. Powell, was entitled "Twenty Ways the
World Could End Suddenly". Now there''s a title guaranteed to
brighten one''s day! He grouped the possible catastrophic
scenarios into four categories: natural disasters, human-triggered
disasters, willful self-destruction and a greater force directed
against us. In the last category, Powell cites as threat number 20
what I would call the Bob Newhart scenario. Thanks to Brian
Trumbore, my wife and I had the pleasure of seeing Newhart
perform at a local theater a few weeks ago. You may recall that
Newhart had several different TV series. The final episode of
one series, in which Newhart was an innkeeper, ended with
Newhart waking up in bed with his wife from an earlier series!
He told that wife that he had this strange dream, which consisted
of the entire second series. Powell''s analogous version is that
we''ll wake up from all this and find that our existence was just a
dream.
Somehow, number 20 doesn''t worry me at all; nor does number
18, an alien invasion, or number 19, divine intervention.
Actually, in the divine category, Powell did include the
possibility that some group, presuming to act on God''s behalf,
might perform some dastardly act - eerily close to September 11.
Powell''s self-destruction scenarios included global war, robots
taking over and mass insanity due to an extension of our life
spans to perhaps 200 years. Under human-triggered disasters
global warming, ecological collapse, biotech disasters and a
couple of others round out the bill.
Some of these are rather disturbing possibilities, but it''s really the
natural disasters that I''m concerned about. Here, Powell''s threats
included such things as huge volcanic eruptions extending over a
prolonged period, wandering black holes headed our way, giant
solar flares and gamma ray bursts from nearby mergers of
collapsing stars, a global epidemic and at number 1, asteroid
impact - my favorite.
However, after reading an article in a more recent Discover, next
month''s June 2002 issue, I''ve decided that I should temper my
concern over an asteroid impact and pay attention to the more
immediate environmental threats. The article, "What Wiped Out
the Dinosaurs?" is by Edwin Dobb. I almost skipped over the
article, thinking that I already knew the answer, namely, the
aforementioned asteroid. Then I noticed that the article
mentioned Bozeman, Montana and Jack Horner, one of my
favorite characters. Without a formal college degree, this 55-year
old paleontologist records among his achievements the finding of
the first dinosaur egg in North America, the first evidence for
dinosaur nesting and parental care, the first dinosaur embryos,
uncovering the largest Tyrannosaurus rex, the largest duck-billed
dinosaur, etc., etc. Horner, was also technical advisor to Steven
Spielberg in the making of the movie Jurassic Park. For the past
22 years or so, Horner has been based at the Museum of the
Rockies in Bozeman, Montana.
Bozeman has a special place in my heart, possibly saving my
marriage of over 51 years. Many years ago, we drove out West
with our two young sons. We stopped in Yellowstone for a 3-
night camping experience in a tent a neighbor had insisted we
take on the trip. It was our first, and last, family tenting
experience. Aside from the grizzly bears, the fact our youngest
son was trying to set a trap for one and the three nights of severe
thunderstorms, our older son was sick and not reacting favorably
to the sulfurous odor of the bubbling springs.
I too became ill and the morning of our departure my wife,
disgusted with my ineptitude, had to figure out how to fold up
the wet tent. (I''ve always had trouble wrapping Christmas
presents, let alone tents!) She was not a happy camper, literally,
and threatened to fly home. Fortunately, there were no planes
within reach that morning and we drove to Bozeman. There we
found a very comfortable, dry motel. Everyone''s spirits, notably
my wife''s, were revived and we continued on to Canada, the tent
remaining in its carrier the rest of the trip.
Montana is also the site of the Hell Creek Formation, a treasure
trove of dinosaur fossils exposed when the last ice cap retreated.
The beauty of the site is also that the layers available for study
include the periods before, during and after the asteroid impact of
65 million years ago. Horner and others have now shifted their
attention away from the dinosaurs to the animal and plant life
present before and after the asteroid impact. Among the other
workers are William Clemens of Berkeley, Nan Crystal Arens of
Hobart and William Smith Colleges and Joseph Hartman of the
University of North Dakota. We''ll see that their studies have an
alarming message for us today.
Clemens and his coworkers were most interested in the survivors
of the asteroid impact and the recovery of life after the impact.
Many animals did survive the impact. The most important for us
were those tiny mammals about the size of a mouse that were our
ancestors. Crocodiles survived, turtles survived and birds (the
winged dinosaurs) survived. I was surprised to learn that frogs
and salamanders also survived. Today, we read and hear
repeated stories of frogs dying out all over the world. I don''t
know about you, but I''m now a bit uneasy. If frogs could survive
the asteroid impact, what''s going on today that threatens to wipe
them out? And what does it mean for our own survival?
Let''s go back millions of years before the asteroid hit. North
America looked quite different. There was the Western Interior
Seaway, a body of water that extended from the Gulf of Mexico
to Canada and that periodically advanced and retreated. A few
million years before the asteroid, the Seaway retreated and the
continent would have had pretty much the shape it has today. All
this changing of the land and seascapes must have put a good
deal of stress on the plant and animal life in the Hell Creek area.
In fact, what Arens found is that before the extinction the number
of species of flowering plants had dropped from over a hundred
to just ten!
Now consider what effect this might have had on the dinosaurs.
Take Tyrannosaurus rex, a carnivore who liked to dine on other
dinosaurs such as Triceratops. But Triceratops was a plant eater
and there were fewer plants to eat. This is not a great situation
for either animal - with fewer Triceratops and other plant eaters,
T. rex also had a problem finding a snack. Could it be that they
were set up for extinction before the asteroid came along? That''s
the scenario that''s emerging.
Enter the mollusks such as clams and snails, Joseph Hartman''s
field of expertise. While the Seaway advanced and retreated,
there were always freshwater streams and rivers with an
abundance of freshwater mollusks such as clams and snails. The
number of freshwater mollusks would multiply as the Seaway
retreated and decline as the Seaway advanced, bearing its
saltwater. Hartman found that, like the flowering plants, the
freshwater mollusks experienced a 90 percent decline in
population before the asteroid hit. This suggests that the Seaway
was still active long after it was thought to have disappeared
from the continent. Other changes in plant life indicate that a
cooling of the climate also took place around this time.
Out of these findings comes the proposal that the asteroid impact
came at a time of deep environmental stress and that the impact
of the asteroid, with its own environmental consequences, tipped
the scale to extinction for the dinosaurs. Arens suggests that
today we may be in another period of climate alteration and that
our own contributions to environmental stress might be the factor
that could tip the scale to another mass extinction.
Let''s keep a close watch on those frogs!
Allen F. Bortrum
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