Bruce S. Lieberman is Dean's Professor of Evolutionary Biology and senior curator of invertebrate paleontology at the University of Kansas, where he also directs the Paleontological Institute and is editor in chief of the Treatise on Invertebrate Paleontology. His research focuses on patterns and processes of evolution and extinction using the fossil record.

Niles Eldredge is an invertebrate paleontologist, an evolutionary biologist, and an emeritus curator of invertebrates at the American Museum of Natural History. He discovered punctuated equilibria with Stephen Jay Gould and played a leading role in developing the field of macroevolution. His work has also emphasized understanding the biodiversity crisis and documenting Darwin's discovery of natural selection and evolution.