Prof. Emeritus James Hopson receives award for seminal work on mammalian evolution

Kevin Jiang
Science Writer and Media Relations SpecialistUniversity of Chicago Medicine and Biological Sciences

Prof. Emeritus James Allen “Jim” Hopson, a distinguished educator and paleontologist whose seminal work on the earliest forerunners to mammals shaped our understanding of mammalian evolutionary history, was awarded the prestigious Romer-Simpson Medal at the Society of Vertebrate Paleontology’s annual meeting in October.

The society’s highest honor is a lifetime achievement award given each year to a scientist for “sustained and outstanding scholarly excellence in the discipline of vertebrate paleontology." It is named, in part, after Alfred Sherwood Romer—a “father figure” in the field of vertebrate paleontology, who spent his early career as a professor in the Geology Department and curator of the Walker Museum at the University of Chicago.

Hopson, professor emeritus of organismal biology and anatomy and a member of the Committee on Evolutionary Biology, has focused his research on the evolutionary history of the earliest relatives to mammals, the synapsids—a group of mammal-like reptiles that arose about 300 million years ago. His contributions in interpreting the synapsid fossil record, which spans nearly 100 million years, helped lay the foundation for the study of the origins of mammals.

“I feel extraordinarily honored to be recognized by the Society of Vertebrate Paleontology for lifetime achievement in the field to which I have devoted my research career,” Hopson said. “In addition, Al Romer and George Gaylord Simpson, for whom the award was named, were the two greatest vertebrate paleontologists of the 20th century and my intellectual heroes, so it has that much more significance to me.”

Early in Hopson’s career, the prevailing hypothesis was mammals originated from several different groups of mammal-like reptiles. But his work suggested that mammals descended from a single lineage of mammal-like reptiles. This has been verified by subsequent studies and has shaped modern phylogenetic analyses of mammalian evolution.

‘an immeasurable impact’

Hopson’s research has been fundamental in establishing concepts used to interpret mammalian fossils. His work on tooth replacement in mammal-like reptiles was one of the first to show that growth patterns and dental anatomy can be used to study these extinct species. Largely because of Hopson’s contributions to the field, the stunning series of ancient mammal and mammal-like species currently being discovered in China, much of it led by Zhe-Xi Luo, professor organismal biology and anatomy, can be accurately placed on the mammalian family tree.

He also made seminal contributions to the study of dinosaur brain evolution and behavior—including being among the first to suggest peculiar features in duckbill dinosaurs could be a result of sexual selection, and that dinosaurs likely possessed a wide range of metabolic levels.

“Jim has had an immeasurable impact on our understanding of the early evolutionary history of mammals, and has also trained many, perhaps most, of the stream of brilliant vertebrate paleontology PhDs that have emerged from the University of Chicago over the past few decades,” said Michael Coates, professor of organismal biology and anatomy and chair of the Committee on Evolutionary Biology. “Jim is a hugely respected figure, and his achievement is more than well-deserved.”

The Connecticut native earned an undergraduate degree in geology from Yale University in 1957, and later carried out his graduate work at the University of Chicago under the mentorship of famed paleontologist Everett Olson in what is now known as the Committee on Evolutionary Biology.

After working on vertebrate paleontology collections at Yale’s Peabody Museum, while simultaneously finishing his thesis, Hopson returned to the University of Chicago in 1967 as a faculty member in what is now the Department of Organismal Biology and Anatomy.

Hopson spent the rest of his career at UChicago and made frequent trips to South Africa, the “heartland” of synapsid evolution that became his de facto second home. Hopson helped make the department and the University’s evolutionary biology and paleontology programs among the strongest in the world.

Inspiring students

For decades, Hopson taught popular classes on comparative vertebrate anatomy and vertebrate paleobiology, and received a Quantrell teaching award in 1996. He mentored and inspired graduate students who went on to have fruitful careers in paleontology.

“Jim’s honor is well deserved for an esteemed scholar whose career was spent at the University and who was my colleague and mentor for 25 years,” said Paul Sereno, professor of organismal biology and anatomy and director of the Fossil Lab. “He was an integral part of an effort in the 1960s at the University of Chicago, in both organismal biology and anatomy and geosciences, that resulted in the launch of the premiere journal Paleobiology.”

“Jim Hopson is simply the best paleontologist I know,” said Jim Clark, professor of biology at George Washington University and a former graduate student of Hopson. “His knowledge is immense and his experience vast, and all of this is rolled up into an incredibly likeable person.”

Although continuing to do research in retirement, Hopson is as passionate a teacher as ever and still has plenty of advice to give. “Young paleontologists need to know the anatomy of fossils extremely well, but they also need to know genetics, development, behavior, ecology and other areas that help us to interpret the fossils,” Hopson said. “Paleontology is now primarily a biological science. Some knowledge of geology is important, of course, but the major advances in paleontology are being made in the context of biology.

“And if they get the opportunity to go into the field to collect fossils, they should take it. New fossils are the life blood of paleontology!”