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01/26/2005
A Surprising Last Meal
My last two columns celebrated the successes of the Mars rovers
and the Huygens probe that landed on Saturn’s moon Titan. But
not all went right with the Titan mission. Pity poor David
Atkinson of the University of Idaho. According to an AP report
by Nicholas Geranios posted January 21 on AOL News,
Atkinson spent 18 years designing an experiment that was to
measure the winds on Titan. The Huygens probe was to send
back data on two channels, one operating on a very stable
frequency, the other on a not so stable frequency. Someone
apparently forgot to send the order to turn on the stable
frequency channel, the channel on which the wind data were to
be sent! This may account for my statement last week that one
channel wasn’t working. The space program has had its share of
human errors.
Nevertheless, Huygens has opened up a new world on Titan and
more details were revealed at a European Space Agency press
conference on January 21. Titan is indeed a weird world on
which there are rainstorms of liquid methane that fuel the
streams and rivers that flow from the highlands down to the flat
lowlands. What intrigued me was the finding of an isotope of
argon gas that the scientists say is evidence of volcanic activity
on Titan. However, instead of ejecting molten lava, when these
volcanoes erupt(ed) they spit out water ice, very cold water ice!
I’ve mentioned before that a highlight of my life was watching
from the deck of a cruise ship at night while Kilauea in Hawaii
erupted and the molten lava flowing into the sea. Now I imagine
a tourist on Titan cruising on a sea of liquid methane watching a
volcano erupting chunks of ice tumbling down the mountain into
the methane sea – weird!
So much for Titan. Regular readers know that I’m a sucker for
anything to do with space or with our roots, whether it is the Big
Bang or our distant ancestor, a fungus. Most people, I imagine,
have trouble relating to a fungal relative and can identify more
closely with an ancestor that was a mammal. The prevailing
view of our mammalian ancestors has been that during the age of
the dinosaurs the mammals were small critters the size of a rat or
a shrew. It was assumed that to avoid the humongous dinosaurs,
the little mammals had to scurry around underfoot keeping a
wary eye out to avoid being eaten.
This view of those early mammals is bolstered by the fact that it
wasn’t until the dinosaurs became extinct around 65 million
years ago that mammals took over and evolved into the huge
variety of animals we are today. One of the exciting things about
our knowledge of evolution is that, as more fossils are found,
some of the prevailing wisdom is overturned or at least modified
significantly. For example, when we think of the age of the
dinosaurs, we think of huge creatures; some recently discovered
fossils are of even larger behemoths than known previously. But
we forget that not all dinosaurs were giants; some were relatively
small and baby dinosaurs could be even smaller.
Which brings us to what one mammal called R. robustus had for
its last meal approximately 130 million years ago. The discovery
of fossil skulls of R. robustus was reported in 2001 and, as the
name implies, R. robustus was larger than any previously known
mammals of that era. This month, in the January 13, 2005 issue
of Nature, a team of paleontologists reports the discovery in
China of a nearly complete skeleton of R. robustus, about the
size of a cat. Let’s call this critter Robbie for short. In an article
on the work in the January 14, 2005 issue of Science by Erik
Stokstad, one team member, Yaoming Hu, is quoted as saying
that Robbie resembled that lovable animal, the Tasmanian devil,
with sharp teeth and a powerful lower jaw.
OK, what about that last meal? Inside Robbie’s rib cage, likely
location of its stomach, were the scattered teeth and bones of a
dinosaur! The bones were those of a Psittacosaurus, a so-called
“parrot dinosaur” because of its horny beak. Apparently, Robbie
wasn’t able to chew his food very well but just ripped the
dinosaur apart and gulped it down. The dinosaur was just a
baby, only about five inches long, but it was a dinosaur. It would
seem that, given his sharp teeth, Robbie was capable of attacking
and devouring the little dinosaur. However, it can’t be ruled out
that Robbie might have been a scavenger like the hyena.
The Liaoning Province in northeastern China is a truly fertile
area for fossil finding. The same team reported the discovery of
another, even larger skeleton of a mammal that was also about
130 million years old. In fact, this fossil is the largest fossil of a
mammal ever found that lived during the dinosaur era. The
fossil, a relative of R. robustus, has been dubbed R. giganticus.
It was more than 3 feet long and is estimated to have weighed
more than 30 pounds, about the size of a coyote.
These latest fossil discoveries have shaken up the view of the
tiny mammals scurrying in the shadows of the dinosaurs, at least
back 130 million years ago. Were Robbie and his mammal
relatives competing with the dinos for food back in those days?
Could competition between the dinos and Robbie and his friends
have driven the evolution of the dinos into the humongous
creatures they became? If so, did the larger dinos end up eating
the larger mammals, driving them to extinction? I’m wondering
about this last possibility since I haven’t heard of any of these
large mammal fossils being found from the period some 60
million years later, just before the dinos were wiped out.
To my way of thinking, evolution starts at the Big Bang and goes
through the formation of stars and galaxies and planets such as
Earth, which contains our own local evolutionary history. It
pains me to see reports in media ranging from CNN to our Star
Ledger newspaper about the actions of school officials in Dover,
Pennsylvania. Dover is in the same area of Pennsylvania that I
grew up in and in one account was termed Pennsylvania Dutch
country. My father was Pennsylvania Dutch. Last week, Dover
school officials required that a statement be read to biology
classes stating that “intelligent design” is an alternative to the
theory of evolution. This follows on the heels of a federal
judge’s order to remove certain stickers placed in textbooks in
Cobb County Georgia. The stickers called evolution a theory,
not a fact. Both were ploys to lend credence to the creationist
view.
In this centennial year of Einstein’s theory of relativity, those
same individuals could say it’s a theory, not a fact. Tell that to
the thousands of people who died in Hiroshima and Nagasaki
because E = mc^2, derived from the “theory”! Quantum
mechanics could be called a theory, not a fact. Tell that to those
who designed the silicon chips and electronic circuits that have
changed our world based on quantum theory. The evidence for
evolution is overwhelming but, as we’ve seen in this column, we
still have not dug up enough to complete the picture. However,
if sometime in the future another theory should supplant
evolution, that theory will have to encompass evolution within it
and the dinosaurs and fungi will still have existed to marvel at
and explain. OK, I promise to get off my soapbox next week.
Allen F. Bortrum
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