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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