How can we know the color of the birds that filled the ancient skies, the daily diet of extinct creatures, or when the ancestors of today’s penguins became used to the cold? Clues to these mysteries—and many more—are buried deep in the chemical labels that outlast the lives of animals and persist into their fossil records.

Using spectroscopy, Smithsonian scientist Daniel B. Thomas becomes a time-travelling detective, uncovering the chemical secrets that tell long-lost animal stories. Tonight, he explores how the chemistry locked in fossils can reveal the diet, lifestyle, habitat, physiology, and even the color of creatures, allowing us to reconstruct ancient life in exquisite and fascinating detail.

6:45 to 7:45 p.m. Atoms, Isotopes, and Molecules

Extracting chemical evidence from fossils reveals a wide range of ecological information.

8 to 8:45 p.m. The Color of Birds

Birds use color—probably inherited from their dinosaur ancestors—for many functions, from the covert disguise of nightjars, whose feathers are patterned like leaf litter, to the overt and outlandish display of the peacock, whose patterns are a lure for females.

Thomas is a research fellow at the Natural History Museum.