Clever Apes #27: Breaking the fossil record
Dinosaurs loom large in our imaginations not just because they were in fact enormous, but also they are so ridiculously old. There has always been a big, impenetrable curtain separating us from prehistoric life. Sure, we have some ancient bones, but those had long since turned to stone. Any actual tissue, the stuff of flesh-and-blood creatures, is irrevocably lost, lasting only a few tens of thousands of years in most cases. Maybe a few stray organic molecules could persist for a few million if, say, they were frozen deep within primeval ice.
So, needless to say, it came as something of a shock when Mary Schweitzer discovered that she had some 68-million-year-old dinosaur tissue on her hands.
The find was and is controversial. Many scientists are skeptical or outright dismissive of the idea that tissue could have persisted inside the partially fossilized thigh bone of a T. rex. But since then Schweitzer and her collaborators have gradually built up evidence that the find is real. And most recently, Joseph Orgel of the Illinois Institute of Technology has begun to understand how mummified dino-flesh could possibly have survived a thousand times longer than was thought possible.
Orgel used x-ray diffraction, a kind of molecular imaging technique, to understand how the dinosaur tissue is structured in detail. The particular stuff they have in hand is collagen, a material found in our bones, tendons, blood vessels and skin. It is itself a hardy molecule, and Orgel found that the protein sequences preserved in their fossils came from the innermost, protected part of the collagen fiber. So it’s possible that collagen’s tough, ropelike structure preserved a tender bit of dinosaur jerky inside.
Keep in mind, this is not DNA. We will not be cloning Barney from this stuff. But understanding how these proteins can be shielded from decay for so long could hold practical lessons for modern medicine. If you’re repairing, say, a bone or cartilage, you might be able to leverage or mimic nature’s ability to make durable organic materials that don’t degrade, in effect, forever.
Also in today’s episode, we consider another example of design inspired by biology. Dr. Phillip Messersmith’s muse is the blue mussel – a bivalve that secretes a unique adhesive to stick itself to rocks or boat hulls or wherever it feels like sticking. (They form their connective threads and tacky pads through a kind of shellfish injection-molding process. The video below, provided by the Messersmith lab, captures an amazing example.) This stuff turns out to have some key qualities that a surgeon would envy. It starts as a liquid and solidifies quickly, it functions well under water and it’s sticky as hell.
That’s a big advantage over the medical glues out there that doctors use to attach or repair tissues. The safest ones are too weak. The strongest ones (basically, super glue) are toxic. Messersmith and his lab-mates at Northwestern University are using the fundamentals of the mussel glue to design their own version, which they demonstrated for us on some sausage casing.
So someday, maybe they’ll be able to install a dino-inspired bone patch in your body, and lock it down with some mussel glue. Until then, don’t forget to subscribe to our podcast, follow us on Twitter, and find us on Facebook.