in Search of... with your host Leonard Nimoy.
Posted on 05/01/2006 8:29:14 AM PDT by SirLinksalot
Dinosaur Shocker
By Helen Fields
Neatly dressed in blue Capri pants and a sleeveless top, long hair flowing over her bare shoulders, Mary Schweitzer sits at a microscope in a dim lab, her face lit only by a glowing computer screen showing a network of thin, branching vessels. That’s right, blood vessels. From a dinosaur. “Ho-ho-ho, I am excite-e-e-e-d,” she chuckles. “I am, like, really excited.”
After 68 million years in the ground, a Tyrannosaurus rex found in Montana was dug up, its leg bone was broken in pieces, and fragments were dissolved in acid in Schweitzer’s laboratory at North Carolina State University in Raleigh. “Cool beans,” she says, looking at the image on the screen.
It was big news indeed last year when Schweitzer announced she had discovered blood vessels and structures that looked like whole cells inside that T. rex bone—the first observation of its kind. The finding amazed colleagues, who had never imagined that even a trace of still-soft dinosaur tissue could survive. After all, as any textbook will tell you, when an animal dies, soft tissues such as blood vessels, muscle and skin decay and disappear over time, while hard tissues like bone may gradually acquire minerals from the environment and become fossils. Schweitzer, one of the first scientists to use the tools of modern cell biology to study dinosaurs, has upended the conventional wisdom by showing that some rock-hard fossils tens of millions of years old may have remnants of soft tissues hidden away in their interiors. “The reason it hasn’t been discovered before is no right-thinking paleontologist would do what Mary did with her specimens. We don’t go to all this effort to dig this stuff out of the ground to then destroy it in acid,” says dinosaur paleontologist Thomas Holtz Jr., of the University of Maryland. “It’s great science.” The observations could shed new light on how dinosaurs evolved and how their muscles and blood vessels worked. And the new findings might help settle a long-running debate about whether dinosaurs were warmblooded, coldblooded—or both.
Meanwhile, Schweitzer’s research has been hijacked by “young earth” creationists, who insist that dinosaur soft tissue couldn’t possibly survive millions of years. They claim her discoveries support their belief, based on their interpretation of Genesis, that the earth is only a few thousand years old. Of course, it’s not unusual for a paleontologist to differ with creationists. But when creationists misrepresent Schweitzer’s data, she takes it personally: she describes herself as “a complete and total Christian.” On a shelf in her office is a plaque bearing an Old Testament verse: “For I know the plans I have for you,” declares the Lord, “plans to prosper you and not to harm you, plans to give you hope and a future.”
It may be that Schweitzer’s unorthodox approach to paleontology can be traced to her roundabout career path. Growing up in Helena, Montana, she went through a phase when, like many kids, she was fascinated by dinosaurs. In fact, at age 5 she announced she was going to be a paleontologist. But first she got a college degree in communicative disorders, married, had three children and briefly taught remedial biology to high schoolers. In 1989, a dozen years after she graduated from college, she sat in on a class at Montana State University taught by paleontologist Jack Horner, of the Museum of the Rockies, now an affiliate of the Smithsonian Institution. The lectures reignited her passion for dinosaurs. Soon after, she talked her way into a volunteer position in Horner’s lab and began to pursue a doctorate in paleontology.
She initially thought she would study how the microscopic structure of dinosaur bones differs depending on how much the animal weighs. But then came the incident with the red spots.
AdvertisementIn 1991, Schweitzer was trying to study thin slices of bones from a 65-million-year-old T. rex. She was having a hard time getting the slices to stick to a glass slide, so she sought help from a molecular biologist at the university. The biologist, Gayle Callis, happened to take the slides to a veterinary conference, where she set up the ancient samples for others to look at. One of the vets went up to Callis and said, “Do you know you have red blood cells in that bone?” Sure enough, under a microscope, it appeared that the bone was filled with red disks. Later, Schweitzer recalls, “I looked at this and I looked at this and I thought, this can’t be. Red blood cells don’t preserve.”
Schweitzer showed the slide to Horner. “When she first found the red-blood-cell-looking structures, I said, Yep, that’s what they look like,” her mentor recalls. He thought it was possible they were red blood cells, but he gave her some advice: “Now see if you can find some evidence to show that that’s not what they are.”
What she found instead was evidence of heme in the bones—additional support for the idea that they were red blood cells. Heme is a part of hemoglobin, the protein that carries oxygen in the blood and gives red blood cells their color. “It got me real curious as to exceptional preservation,” she says. If particles of that one dinosaur were able to hang around for 65 million years, maybe the textbooks were wrong about fossilization.
Schweitzer tends to be self-deprecating, claiming to be hopeless at computers, lab work and talking to strangers. But colleagues admire her, saying she’s determined and hard-working and has mastered a number of complex laboratory techniques that are beyond the skills of most paleontologists. And asking unusual questions took a lot of nerve. “If you point her in a direction and say, don’t go that way, she’s the kind of person who’ll say, Why?—and she goes and tests it herself,” says Gregory Erickson, a paleobiologist at Florida State University. Schweitzer takes risks, says Karen Chin, a University of Colorado paleontologist. “It could be a big payoff or it could just be kind of a ho-hum research project.”
In 2000, Bob Harmon, a field crew chief from the Museum of the Rockies, was eating his lunch in a remote Montana canyon when he looked up and saw a bone sticking out of a rock wall. That bone turned out to be part of what may be the best preserved T. rex in the world. Over the next three summers, workers chipped away at the dinosaur, gradually removing it from the cliff face. They called it B. rex in Harmon’s honor and nicknamed it Bob. In 2001, they encased a section of the dinosaur and the surrounding dirt in plaster to protect it. The package weighed more than 2,000 pounds, which turned out to be just above their helicopter’s capacity, so they split it in half. One of B. rex’s leg bones was broken into two big pieces and several fragments—just what Schweitzer needed for her micro-scale explorations.
It turned out Bob had been misnamed. “It’s a girl and she’s pregnant,” Schweitzer recalls telling her lab technician when she looked at the fragments. On the hollow inside surface of the femur, Schweitzer had found scraps of bone that gave a surprising amount of information about the dinosaur that made them. Bones may seem as steady as stone, but they’re actually constantly in flux. Pregnant women use calcium from their bones to build the skeleton of a developing fetus. Before female birds start to lay eggs, they form a calcium-rich structure called medullary bone on the inside of their leg and other bones; they draw on it during the breeding season to make eggshells. Schweitzer had studied birds, so she knew about medullary bone, and that’s what she figured she was seeing in that T. rex specimen.
Most paleontologists now agree that birds are the dinosaurs’ closest living relatives. In fact, they say that birds are dinosaurs—colorful, incredibly diverse, cute little feathered dinosaurs. The theropod of the Jurassic forests lives on in the goldfinch visiting the backyard feeder, the toucans of the tropics and the ostriches loping across the African savanna.
To understand her dinosaur bone, Schweitzer turned to two of the most primitive living birds: ostriches and emus. In the summer of 2004, she asked several ostrich breeders for female bones. A farmer called, months later. “Y’all still need that lady ostrich?” The dead bird had been in the farmer’s backhoe bucket for several days in the North Carolina heat. Schweitzer and two colleagues collected a leg from the fragrant carcass and drove it back to Raleigh.
AdvertisementAs far as anyone can tell, Schweitzer was right: Bob the dinosaur really did have a store of medullary bone when she died. A paper published in Science last June presents microscope pictures of medullary bone from ostrich and emu side by side with dinosaur bone, showing near-identical features.
In the course of testing a B. rex bone fragment further, Schweitzer asked her lab technician, Jennifer Wittmeyer, to put it in weak acid, which slowly dissolves bone, including fossilized bone—but not soft tissues. One Friday night in January 2004, Wittmeyer was in the lab as usual. She took out a fossil chip that had been in the acid for three days and put it under the microscope to take a picture. “[The chip] was curved so much, I couldn’t get it in focus,” Wittmeyer recalls. She used forceps to flatten it. “My forceps kind of sunk into it, made a little indentation and it curled back up. I was like, stop it!” Finally, through her irritation, she realized what she had: a fragment of dinosaur soft tissue left behind when the mineral bone around it had dissolved. Suddenly Schweitzer and Wittmeyer were dealing with something no one else had ever seen. For a couple of weeks, Wittmeyer said, it was like Christmas every day.
In the lab, Wittmeyer now takes out a dish with six compartments, each holding a little brown dab of tissue in clear liquid, and puts it under the microscope lens. Inside each specimen is a fine network of almost-clear branching vessels—the tissue of a female Tyrannosaurus rex that strode through the forests 68 million years ago, preparing to lay eggs. Close up, the blood vessels from that T. rex and her ostrich cousins look remarkably alike. Inside the dinosaur vessels are things Schweitzer diplomatically calls “round microstructures” in the journal article, out of an abundance of scientific caution, but they are red and round, and she and other scientists suspect that they are red blood cells.
Of course, what everyone wants to know is whether DNA might be lurking in that tissue. Wittmeyer, from much experience with the press since the discovery, calls this “the awful question”—whether Schweitzer’s work is paving the road to a real-life version of science fiction’s Jurassic Park, where dinosaurs were regenerated from DNA preserved in amber. But DNA, which carries the genetic script for an animal, is a very fragile molecule. It’s also ridiculously hard to study because it is so easily contaminated with modern biological material, such as microbes or skin cells, while buried or after being dug up. Instead, Schweitzer has been testing her dinosaur tissue samples for proteins, which are a bit hardier and more readily distinguished from contaminants. Specifically, she’s been looking for collagen, elastin and hemoglobin. Collagen makes up much of the bone scaffolding, elastin is wrapped around blood vessels and hemoglobin carries oxygen inside red blood cells.
Because the chemical makeup of proteins changes through evolution, scientists can study protein sequences to learn more about how dinosaurs evolved. And because proteins do all the work in the body, studying them could someday help scientists understand dinosaur physiology—how their muscles and blood vessels worked, for example.
Proteins are much too tiny to pick out with a microscope. To look for them, Schweitzer uses antibodies, immune system molecules that recognize and bind to specific sections of proteins. Schweitzer and Wittmeyer have been using antibodies to chicken collagen, cow elastin and ostrich hemoglobin to search for similar molecules in the dinosaur tissue. At an October 2005 paleontology conference, Schweitzer presented preliminary evidence that she has detected real dinosaur proteins in her specimens.
Further discoveries in the past year have shown that the discovery of soft tissue in B. rex wasn’t just a fluke. Schweitzer and Wittmeyer have now found probable blood vessels, bone-building cells and connective tissue in another T. rex, in a theropod from Argentina and in a 300,000-year-old woolly mammoth fossil. Schweitzer’s work is “showing us we really don’t understand decay,” Holtz says. “There’s a lot of really basic stuff in nature that people just make assumptions about.”
young-earth creationists also see Schweitzer’s work as revolutionary, but in an entirely different way. They first seized upon Schweitzer’s work after she wrote an article for the popular science magazine Earth in 1997 about possible red blood cells in her dinosaur specimens. Creation magazine claimed that Schweitzer’s research was “powerful testimony against the whole idea of dinosaurs living millions of years ago. It speaks volumes for the Bible’s account of a recent creation.”
This drives Schweitzer crazy. Geologists have established that the Hell Creek Formation, where B. rex was found, is 68 million years old, and so are the bones buried in it. She’s horrified that some Christians accuse her of hiding the true meaning of her data. “They treat you really bad,” she says. “They twist your words and they manipulate your data.” For her, science and religion represent two different ways of looking at the world; invoking the hand of God to explain natural phenomena breaks the rules of science. After all, she says, what God asks is faith, not evidence. “If you have all this evidence and proof positive that God exists, you don’t need faith. I think he kind of designed it so that we’d never be able to prove his existence. And I think that’s really cool.”
By definition, there is a lot that scientists don’t know, because the whole point of science is to explore the unknown. By being clear that scientists haven’t explained everything, Schweitzer leaves room for other explanations. “I think that we’re always wise to leave certain doors open,” she says.
But schweitzer’s interest in the long-term preservation of molecules and cells does have an otherworldly dimension: she’s collaborating with NASA scientists on the search for evidence of possible past life on Mars, Saturn’s moon Titan, and other heavenly bodies. (Scientists announced this spring, for instance, that Saturn’s tiny moon Enceladus appears to have liquid water, a probable precondition for life.)
Astrobiology is one of the wackier branches of biology, dealing in life that might or might not exist and might or might not take any recognizable form. “For almost everybody who works on NASA stuff, they are just in hog heaven, working on astrobiology questions,” Schweitzer says. Her NASA research involves using antibodies to probe for signs of life in unexpected places. “For me, it’s the means to an end. I really want to know about my dinosaurs.”
AdvertisementTo that purpose, Schweitzer, with Wittmeyer, spends hours in front of microscopes in dark rooms. To a fourth-generation Montanan, even the relatively laid-back Raleigh area is a big city. She reminisces wistfully about scouting for field sites on horseback in Montana. “Paleontology by microscope is not that fun,” she says. “I’d much rather be out tromping around.”
“My eyeballs are just absolutely fried,” Schweitzer says after hours of gazing through the microscope’s eyepieces at glowing vessels and blobs. You could call it the price she pays for not being typical.
There were other links posted on this thread about human and dinosaur footprints. Personally I have a heard time believing any human would want to walk down the lane next to a dinosaur but maybe they got along. I wasn't there so I can't possibly know.
Like Liberals, ID'ers seem to be both phyically and intellectually lazy and I am tired of repeating myself."Like Liberals, ID'ers seem to be both phyically and intellectually lazy and I am tired of repeating myself."
In other words, everyone who beleives in ID is a dope, and just chuck them in with the liberals...and no, I won't explain myself because I'm too intellectually superior to do so."
"Now how are you gaining scientific credence with ID? IS it through the scientific process? Nope... cause lies fall apart in front of the scientific process."
This is a ridiculous statement....It completely contradicts itself.....
I love these threads, you get to see how God-fearing Christians like myself are just simply too stupid to grasp the concept that science holds all the answers to the universe.....silly me.......
No, you're wrong about the definition of trolling. Trolling is not posting to one topic only. Trolling is "fishing" for responses. When you pick fights, such as calling people ACLU allies, you're trolling. You're using fighting words. You're not showing interest in the topic, you're interest seems to be to get a rise out of people who are interested in the topic. That's trolling.
No one here demands that you change your faith, just that you not tar good folks like Mary Schweitzer who, according to the article, has passages from the Proverbs on her office door. Maybe to you she doesn't believe the "right" things, but that doesn't make her a heathen or atheist.
in Search of... with your host Leonard Nimoy.
Oh, funny. Just make fun of everyone who doesn't fall in line with evolution. And you wonder why so many people reject evolution. People like you. Have you called anyone a Bible-thumper today?
Hehehe... why would I home-school my kids...they teach evolution in school here.
Oh and don't take it that I don't want you to post. I never said or at least I didn't mean for it to come out that way. You actually do seem like a nice person so by all means you are certainly welcomed to respond to me on any post I make and I hope that you do in the future. Please...let's not fight all the time, ok? I didn't mean it like that at all. I just take an attack on science in our schools as an attack on the future of the competitiveness of the US. It does upset me very much and I really do feel it is an important thing to fight for. When you made the statement it "entertained you" I got real angry because of how serious I think the issue is.
Well, then this could be true, right?
God created the heavens and the Earth over 4.5 Billion years. He created various plants and animals by using a process debated here as "evolution". He created humans as humans by having them evolve from other life forms over millions of years.
Why is that so incompatible with your beliefs?
I love science. Why, I even look forward to the astronomy pic of the day on here! LOL
What I have a problem with is people who refuse for anything else to be considered. I wonder if they feel the same about other subjects? Doubtful.
And yes, I am a very nice person.:)
Have a nice afternoon.
OK - public school is good in your opinion b/c they teach evolution. How do you feel about the homosexual agenda in public schools? And are you aware that government-controlled schools are one of the 10 planks of communism?
Just asking...
Because Adam and Eve were humans. No problem with the rest, though the Bible says say "created after their own kind" so I think dogs were dogs and were able to become different kinds of dogs, etc.
Humans are something special, though.
Threads like this just exhibit one of many reasons for the downfall of scientific knowledge among most in the US. Science is an interplay between theory and experimental evidence. If the data contradicts a theory, the theory is modified. You can't take something like Intelligent Design and force the data to fit your theory. It's the same phenomenon that happens when people try to disprove the moon landing or something equally absurd.
Facts prove a theory, not vice versa.
With reasoning skills like that, I can see why you think evolution is 'true'.
Actually not, first you test for putrescin and that it is actually present and not something else. If it is a fact it will either be explained or the origin remain unknown until a explanation is possible!! You do not assume it is putrescin as a fact and that it is x amount of years and therefore cannot be tested. That would be your logic and reasoning.
Further it would not accepted as a fact until tested except by those of opinion that would have a agenda.
One may be horrified without being surprised.
If humans are "special" how come we share 98% of our genes with Chimpanzees?
I admit... that was probably wrong for me to say. I did say it however out of frustration for constantly having to answer the "same questions" over and over again. That is why I made the statement and instead of attempting to offend, I was simply trying to get the ID'ers to do some dang searching for answers on the net instead of making me do it. I went out of my way to read the Creationists/ID web sites... they could do the same if they tried. If you look back at some of my posts... I have to constantly repeat myself over...and over... and over again... often to the same people. So if you took it that I was calling them/you stupid, I apologize.
"Now how are you gaining scientific credence with ID? IS it through the scientific process? Nope... cause lies fall apart in front of the scientific process." This is a ridiculous statement....It completely contradicts itself.....
Now here I have nothing to apologize for. Please look at the next statements I make in the post. I state that since ID cannot be held up to scientific scrutiny, it continues to push itself onto the public schools to win proponents. Now... where am incorrect? That is exactly what it's proponents are doing, right? I then continue to talk about the dangers of using "invisible intelligences" to answer natural phenomena (or was that in another post...). So... where am I wrong?
I love these threads, you get to see how God-fearing Christians like myself are just simply too stupid to grasp the concept that science holds all the answers to the universe.....silly me.......
See... I don't think science currently has all the answers... as a matter of fact it is the job of science to answer the unknown is it not? Now... I don't really care what you believe and what you don't. What I do care about is one thing, that science not be subverted to push a religious belief. That is what ID is... it isn't science and has no place in a science class. Disagree?
So you don't believe humans are any better than chimps? BTW, what is the DNA difference between humans and pigs?
If humans share 98% of their genes with chimps, why can't that suggest a common Creator rather than a common ancestor?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.