Exploring the Ancient DNA of Fossil Mammals

From the Collections posts

The Museum’s Fossil Mammal Collection, one of the world’s largest and most important, has more than 400,000 specimens. There are ancient animals like Paraceratherium, thought to be the largest land mammal that ever lived, and more familiar animals, like mammoths, musk oxen, bison, foxes, and coyotes. All in all, the collection’s shelves, cabinets, and drawers, hold fossils representing an estimated 2,800 genera.  

 

Otto stands next to a table holding an enormous mammal skull (complete with teeth).

Preparator Otto Falkenbach stands next to a Paraceratherium skull from the Museum’s collections (AMNH 18650).

© AMNH


What’s more, some specimens are not fully fossilized yet, meaning they may still carry traces of organic material. These not-quite-there fossils offer researchers the chance to study the genetic makeup of animals that died tens or even hundreds of thousands of years ago.

In 2003, a large-scale study based on extinct bison specimens from the Museum’s collection, along with specimens from the Yukon and Russia, pioneered an approach that used ancient DNA to analyze the dynamics of populations in deep time. 

 

Warehouse type room with aisles of heavy-duty metal shelving housing hundreds of large fossils;  a researcher sits at a table.

The Museum’s collections house hundreds of thousands of fossil mammal specimens.

© AMNH/R. Mickens


In cases where ancient DNA cannot be extracted in enough quantity, or when it’s damaged beyond usefulness, researchers have sometimes been able to pull more limited genetic information from collagen, a protein found in bones. Unlike more fragile DNA, collagen can survive for more than a million years under the right conditions.

Thanks to new techniques, the Museum’s fossil mammal specimens have seen a surge in popularity among researchers around the world, from evolutionary biologists, paleontologists, and even geochemists who are turning to fossils to learn how ancient populations responded to climate changes. 

“In the past 10 years, we have been getting more and more requests for sampling our collections,” says Curator Meng Jin, who is curator-in-charge of fossils mammals in the Division of Paleontology and studies early mammalian evolution. 

 

Dr. West is seated at a table and lifts a fossil from a shallow box containing six specimens in total.

Dr. Abby West conducting research in the fossil mammal collections. 

© AMNH/R. Mickens


Access to the collection is a special boon to the Museum’s graduate students. Last year, Abby West, a paleontologist who received her Ph.D. degree from Columbia University and studied as a graduate fellow at the Richard Gilder Graduate School with Frick Curator of Fossil Mammals Dr. John Flynn, bored tiny samples from 20 specimens of extinct musk oxen in hopes of extracting ancient DNA. West was working to tease out evolutionary relationships and migration histories by making comparisons to the genomes of living relatives.

“You can get the whole genome now from something the size of a fingernail,” says Dr. West. “The techniques are so good, we’re able to work on a finer molecular scale. We don’t need that much material, which allows us to study collections once off-limits for sampling.”

“Twenty years ago, no one would have envisioned this fascinating study,” says Dr. Flynn, “These collections become very important because they allow us to look back in time.”

 

Tags: Fossils