Ask a Scientist

Dr. Niles Eldredge is a paleontologist at the American Museum of Natural History.

On October 27, 2005, students and teachers interviewed Dr. Niles Eldredge, a paleontologist at the American Museum of Natural History. To learn about trilobites, what it’s like to be a paleontologist, and what Dr. Eldredge does in his free time, read the transcript below.
Welcome to our Science Explorations chat with Dr. Niles Eldredge.

What exactly do Paleontologists do?
Paleontologists study fossils and that tells them the history of life on the planet. Fossils are the remains of organisms that lived in the past. The oldest fossils are 3.5 billion years old. They are bacteria almost as old as the Earth itself.

We read that you used to be a mediocre science student. What made science easier for you — other than that you found an area that made you passionate about it?
I was not actually that bad of a science student but I was more interested in French and Latin when I was a grammar student. And music. But I fell in love with the romance of studying ancient life by collecting fossils. Passion is everything! If you have a flair for something and that usually involves having a passion for it, it will be easier for you.

What makes the Galápagos so special?
The Galápagos Islands are right on the Equator and they also have a cold water current going past them so it’s possible to see flamingos and penguins in the same place. When Charles Darwin arrived there in 1835, he saw that there were different species on each of the different islands and he also realized that the tortoises were shaped differently on the different islands. These were some of his first clues that species were not stable but that new species could evolve from old ones.

What technology is used to find fossils?
The old-fashioned way still works best. You walk around an area where rock is exposed and look down on the ground for telltale bits and pieces and those are your main clues that there’s something up on the cliff that’s just beginning to be exposed by erosion. For example, if you see pieces of bones on the ground and then you look up the cliff face and see where the bone fell off and if you are lucky you’ll see the skeleton of an entire dinosaur look down at you. There are some modern technologies of using sound waves mostly in archeology that gives an idea of what lies below the surface. There are some remote-sensing techniques in this digital age, but the old-fashioned way is still the best.

In the introduction it says you study trilobites. What are they and why do you find them interesting?
Trilobites are extinct types of arthropods, which are a huge group of animals that include shrimp, insects, spiders, and horseshoe crabs. Trilobites are some of the oldest known complex animal fossils. They first showed up 535 million years ago and became extinct 245 million years ago in the greatest extinction of all time.

Do you think all of the fossils have been discovered?
Oh no! By no means. There are many places in the United States where the whole hillside is full of rocks that contain millions of fossils — for example, the Catskills in New York. All of the limestone quarries in the Midwestern United States are formed from mud and limey mud that were deposited in ancient seas and they’ve left a very rich fossil record. There are dinosaurs to be discovered in the Rocky Mountain States, tons more.

My son is in first grade and wants to be a paleontologist. How can I foster his interest now?
There are many things that you can do. One obvious one is to go to your local museum, if you have one. Now, you can also go to the museum’s Web site and have almost the same experience. There are also books you can read. I wrote one with my kids called The Fossil Factory that has many activities and tells you places you can go to find fossils in your state.

Have you discovered any bones recently? Where is the most likely place to find dinosaur bones?
I still go out and find trilobites all the time. I collected some just this last summer in upstate New York. The most likely place in the United States to find dinosaur bones is in the Rocky Mountain States like Colorado, Utah, South Dakota, and Wyoming.

Are all paleontologists employed by museums or are they independent workers?
Paleontologists tend to be employed by universities, museums, and oil companies. Oil companies need experts in fossils that help decipher the layers of rocks and help them find oil.

Do you see evidence of waste from cruise ships causing problems for the animals in the Galápagos Islands?
Yes, I have heard about it. When I was in the Galápagos just this last spring, an expert told me that pollution is terrible in the ocean and on land. More people are living on the Galápagos than ever before and fishing has started to deplete the local reserves of fish and other ocean life.

Do you believe in evolution? How about intelligent design or creationism? I have studied a lot about these theories and why there is such a conflict over them. What do you think?
I think that life has evolved. There’s so much evidence for that that it’s a fact. Life has evolved. If you look at the human fossil record of our lineage, our ancestors living four million years ago had brains more like those of chimpanzees than us. It’s not a theory, it’s a fact. Intelligent Design simply says that a designer made life the way we see it. It doesn’t tell us anything about how we can investigate the biological world. We couldn’t understand why some diseases become drug resistant unless we understand how evolution works.

What do you think about cloning? Is human cloning a good idea? How would it affect the way that the human species evolves in the future?
Cloning is a modern technological version of selective breeding, the way humans have been changing the characters of animals and plants like dogs and foods. There’s no way that cloning can change the evolution of humans because there are six billion humans on the planet and we would need to change the genes of every person or nearly every person. But human cloning does raise ethical questions. I’m in favor of stem cell research but I’m not in favor of making new humans as clones of existing people.

How are animals faring with the recent volcanic eruptions? Have the eruptions affected your research?
Volcanic eruptions are a fact of life ever since the earth was formed. The major volcanic eruptions like Krakatoa sent so much ash and vapor that sunsets were colored all over the world and temperatures dropped. When even greater eruptions occur, they can even cause mass extinctions. Even if a local eruption kills some local animals, they’re usually not enough to kill off entire species. So, it shouldn't be a problem right now in the Galápagos.

How do you feel when you look at fossils?
Fossils thrill me. Trilobites have eyes and sometimes I think they’re looking at me.

What other kinds of animals live in the Galápagos besides tortoises?
Iguanas; many kinds of birds, the famous Darwin Finches that have 13 species — some with big beaks to crush big seeds and others with tiny beaks — and the Woodpecker Finch that uses twigs to get insects from inside tree bark. There’re many species of seabirds like the Laysan Albatross and the Blue-Footed and the Red-Footed Boobies; the Galápagos Hawk; and the Flightless Cormorant, which has small wings and cannot fly. There are no bigger animals except for goats, pigs, and dogs that humans have brought in that’ve caused problems for the other animals. I think there’s a non-poisonous, native Galápagos snake.

How long does it take for a dinosaur bone to get from the dig site to the museum?
It depends on many things. Many dinosaurs are known to be in the ground in the Western United States but have not been dug up because it costs millions of dollars to excavate a dinosaur. But for unusual or rare types of dinosaurs, people hurry up and try to excavate in one or two summer seasons. They wrap the bones in plaster to keep them safe, haul them out in trucks, and get to the lab in the museum as fast as they can. Then it takes much longer to put them on display. Most fossils don’t go on display but stay in the research collections — because we have many more fossils than we can put on display — and these fossils are collected for scientific study.

Who influenced you growing up? Did you have a favorite teacher?
I enjoyed many of my teachers. I had a favorite English teacher in high school, but I liked school, so I liked many of my teachers. I was influenced by my parents. When I got to college, I kept my eyes open and tried many fields like Latin and Anthropology. But there was one faculty member at Columbia, Marvin Harris, who was a famous anthropologist and influenced me.

What do you think happened to the dinosaurs?
I agree with most scientists that there was a mass extinction 65 million years ago caused by an extraterrestrial body — probably a comet, maybe an asteroid – [colliding] with the Earth. The explosion would’ve sent a tremendous amount of ash, dust, and water vapor into the upper atmosphere, dimming sunlight on Earth and reducing photosynthesis in plants. Plants are the base of the food chain on both land and in the sea. Once the plants went, then plant-eating animals would have nothing to eat and [soon neither would] the animals that eat the plant eaters like Tyrannosaurus eating Triceratops. So, the dinosaurs became extinct but some animals, like birds, managed to get enough to eat and survive.

What if someone's land has a bed of fossils and they do not want to give permission for digging? Would anyone be able to override their decision for the scientific finds?
That is an interesting question, I think the basic answer is no because we have respect for property rights. If the fossil is found on government lands, permits can be obtained for the excavation, but private property is private property.

Are there many job openings in the field of paleontology and what is the income range?
People should follow their passions to become paleontologists. All my students have managed to find jobs. The salary range is like a normal university range, like $40,000 a year for an assistant professor to $140,000 for older professors.

Do you think humans are on their way to evolving into something else? Into what?
Humans have evolved, but most species — if they are successful — don’t change much once they’ve evolved. New species come when an existing group of animals become isolated from the rest of the animals in the species. Because there are six billion humans on the planet, isolation to form a new species is very unlikely.

What discovery made you well-known?
I worked on trilobites my whole career and the trilobites led me to the idea of “punctuated equilibria.” I’m better known for that idea than any particular fossil that I discovered. “Punctuated equilibria” is the idea that species don’t change much — sometimes not for millions of years — and when evolution happens, it happens relatively rapidly — as populations are isolated and new species evolve.

If you could nominate a national fossil what would it be?
(Laughs) I know most kids would pick Tyrannosaurus Rex, but I would pick Phacopus rana, the frog trilobite that led me to my ideas about “punctuated equilibria.” Phacopus trilobites are found in many states of the U.S., so they’re truly a national trilobite.

What do you do in your free time?
I love to play trumpet and coronet — mostly jazz — and I collect old coronets as a hobby. I also love to play with my grandchildren.

What is the most common evidence you use to infer about the previous life of a fossil?
It depends. If it’s a trilobite, I look at the eyes to get a sense of how the trilobite was able to walk using its eyesight. If the eyes point down, you know they’re a swimmer. If they look ahead, you know that they walk. And if they’re blind, you know that they swam in water that was so deep that sunlight didn’t reach the sea bottom.

Does the Museum really get things to identify like the shell in a crate in the “Solve the Mystery” activity?
Yes, all the time. People bring fossils in and they want to identify them. Sometimes if the fossil is rare, they’ll donate it to the museum and the scientists will study it and publish an article about it. I’ve done that myself. It was a horseshoe crab from Bolivia.

What special skills do paleontologists need?
I would say passion for living things and a desire to bring dead things back to life by understanding fossils as living creatures; also, the ability to travel and collect fossils — though if you can’t travel, you can also work in the lab — and a deep knowledge of biology and geology.

What would you like to study next?
I’ve been working on Charles Darwin for the last two years and how he came to his ideas. Now, I’m interested in how man-made objects like musical instruments, watches, cars, computers, etc. have changed through time.

What's the most interesting fossil you've ever found?
The most interesting fossil I ever found was actually brought to me by an amateur collector from Bolivia. It was a fossil horseshoe crab. It was very rare and it showed that 400 million years ago horseshoe crabs had flexible parts in their bodies and not the single shield they have today.

Thank you so much for your interesting questions and I hope some of you go on to become paleontologists some day.