Tracey Peake:Welcome to North Carolina State University's Audio Abstracts, a podcast that explores both innovative research and the people behind it at NC State.Mary Schweitzer is a paleontologist at NC State. In 2004, she discovered soft tissues preserved inside the leg bone of a 65 million year old Tyrannosaurus rex. This discovery launched a new approach to paleontology, molecular paleontology, which aims to prove that original molecules can preserve inside fossils for millions of years.Dr. Schweitzer is here to tell us what molecular paleontology is, what she's found so far, and what the future holds.Let's start simply. What is molecular paleontology and how is different from what we consider mainstream paleo?Mary Schweitzer:Regular paleontology seeks to get all the information it can out of vertebrate remains, well if you were doing vertebrate paleo. For molecular paleontology, it's kind of the same thing, except instead of mining for bones, we're mining for molecules.One of those things is a molecule called collagen, and dinosaurs had to have collagen to make the bones that they leave behind for us to find. So, for example, in molecular paleontology, we target a molecule, like collagen, and see number one, does it persist. Number two, can we get it out of the bone, and number three, can we interpret it and study it the way we do modern collagen.Peake:What have you found in these fossils, and what is the oldest thing you've been able to extract?Schweitzer:Well, we've actually found evidence for the soft tissues in pretty old bone, in a bunch of bones, triceratops, hadrosaurs of different types, different types of theropods which are the meat-eating dinosaurs show evidence for it. We have not chemically characterized anything other than two dinosaurs: A theropod T-rex and a hadrosaurid which is [inaudible 00:01:53] because what we do is destructive. It's time consuming. It's very, very expensive, and it's very controversial. So, we have limited our total character analysis, if you would, or characterization, molecular characterization of these bones to those two specimens.When we're looking at bone, the ultimate goal is to get protein sequence because if you have sequence, you can ask questions like, who's related to who. You can ask questions like when did this particular adaptation to a molecule arise. You can look at what kind of things, how is a molecule altered from the living state that might inform us on why it's preserved.So all of those things we can ask of the proteins and the tissues that we pull out of the bone.Peake:So we can find these ancient proteins, which leads us to the inevitable Jurassic Park question of DNA. If we can't resurrect the dinosaurs from this information, then what can these findings tell us? What can we learn from these findings?Schweitzer:Well I wouldn't rule out DNA. I would rule out resurrecting a dinosaur because that's a whole different ball of wax, but I personally think we'll probably eventually get some kind of DNA.We can ask questions like how are the molecules of these dinosaurs different from those in living animals, and did those differences confer adaptive advantage to dinosaurs? Something had to make them more successful than anything we've seen really in terms of vertebrates. So, that's the molecules. We can ask questions like, okay feathers are made of a particular kind of keratin. It turns out that the keratin family diversified, so different keratin makes up claw than makes up skin than makes up beak than makes up feather. Now looking at the feather really, really closely, it turns out there's a small region in the protein, in the feather, that gives it the flexibility to allow flight. That's a molecular question. When did flight occur? We know feathers occurred before flight. T-rex had feathers or at least it's relatives did, and it couldn't fly. They had little bitty arms, but when were feathers physically, in terms of physics physically capable of flight? That's a molecular question, and it has to do with a very small region of a very small protein that we know persists in some kinds of feathers. We can ask those questions directly now.Peake:So why are you excited about where this field is heading?Schweitzer:There's so much potential. There is so much potential, and it's not just because I love my dinosaurs, and I want to understand more about them and how they interacted with their world, but it's things like, if we could understand the modifications to molecules that allow them to persist, can we use that to better our own world in terms of things like organoelectronics?So for example, we know that DNA makes really good computers, and it's a great way to store data, except that it degrades. What if we had a molecule that didn't?So here's a question. Sauropod dinosaurs were massive. They were about the size of 14 elephants. How did they get that big? That's a molecular question. How were they able to grow from an egg that's about 18 inches in diameter to 80 tons in the space of about maximum 20 years?We don't have an animal today that is a model for that, but their ability to grow that way has to do with their molecules and their molecule interaction, so the other thing is, they grew to that and maintained that body mass on a plant diet. Plants today are notoriously non-nutritive. Elephants have to eat pretty much every waking moment to maintain their body mass. How did those guys do it? My guess is it's the interactions between the molecules of the dinosaur and the molecules of their gut microbes that allowed them to extract nutrition out of the plant that we can't today.So if we can get that kind of information out of a molecule from a dinosaur, maybe you can use it to better our own world.I guess the one thing that I would say to future students is don't let anybody tell you it's already been done or it's not relevant or you can't do that. The way our world is changing, new technology has opened doors that even five years ago were not possible, so I think that one of the best things we can do in the scientific community is challenge the foundations of what we assume about every ten years. Double check, and don't ever think you can't contribute to a field that's been around for a while because you can. You just have to think outside the box to do it.It's an exciting time to be a scientist in general and a paleontologist in particular.Peake:We've been speaking with Dr. Mary Schweitzer, paleontologist at North Carolina State University.This is Tracey Peake. Thanks for listening to Audio Abstracts.