David Raup became one of the world’s most renowned paleontologists not by excavating dinosaur bones but by using computers, math and statistics to study evolution and extinction.
The former University of Chicago professor and Field Museum of Natural History scientist theorized about the unseen and the why behind the way things are.
“Before Dave, paleontologists tended to just describe what was there, like a T. rex or a trilobite or a wooly mammoth,” said Charles Marshall, director of the University of California Museum of Paleontology. “Dave really transformed the discipline so that people began to ask the question, ‘Why did things exist? Was there a pattern there?’. . . .it just opened up this huge intellectual space.’’
Marshall, a former student of Mr. Raup, called him ‘‘arguably the most influential paleontologist of the late 20th century. I don’t think there’s anybody who really comes close.”
The late Harvard University paleontologist Stephen Jay Gould dubbed him “the world’s most brilliant paleontologist.”
Mr. Raup, 82, who called science “just pure joy,” died of pneumonia July 9 at a hospital in Sturgeon Bay, Wisconsin.
He and a colleague, the late J. John Sepkoski Jr., discovered extinction patterns when they used computer analysis on 27,000 species that died off during the past 300 million years. They theorized that cataclysmic extinctions occur about every 26 million years or so and that one led to the demise of the dinosaurs.
“He detected a 26-million-year periodicity in extinction pulses that continues to intrigue paleontologists and astrophysicists alike,” said David Jablonski, a geophysical sciences professor at the University of Chicago.
Their theory raised the question of whether the reptiles died off because of catastrophic asteroids or comet showers, rather than disease, ungainliness or more resourceful mammals that ate their eggs.
One of Mr. Raup’s books was called “Extinction: Bad Genes or Bad Luck?”
His 1971 work “Principles of Paleontology” was a leading textbook, translated into Chinese, Polish, Russian and Spanish, according to the University of Chicago, where he taught starting in 1980 and from which he retired in 1995. He chaired U. of C.’s department of geophysical sciences from 1982 to 1985.
Some of his most innovative research examined snails, clams and ammonites. He produced computer models of how they might have turned out differently, based on alternative evolutionary circumstances.
In a 1986 Chicago Sun-Times interview, Mr. Raup described science as “a game: chase, exploration, discovery and a little gambling. You have to be able to tolerate losing because you lose most of the time.”
David Raup was born in Boston on April 24, 1933, to botanist parents. As a toddler, he went tromping around the Arctic with them while they collected plants.
“I spent endless hours sitting around campfires, listening to other scientists. I was saturated with science,” he said in the 1986 interview.
After getting his bachelor’s degree from the University of Chicago in 1953, Mr. Raup received a master’s and doctorate in paleontology from Harvard University. He taught at the California Institute of Technology, Johns Hopkins University and the University of Rochester before returning to Chicago.
He oversaw geology and was dean of sciences at the Field Museum from 1978 to 1982 and came back to the U. of C. as a visiting professor in 1977 before joining the faculty there in 1980. He served as president of the Paleontological Society in 1976-1977.
Mr. Raup was a popular co-worker and mentor.
“He lacked the tendency to self-promotion and aggrandizement that often accompanies those who rise to prominence,” Marshall said. “He consciously eschewed being placed on a pedestal, which generated a deep respect in his students and colleagues.”
He enjoyed sailing, camping and golf. Marshall said that, in retirement, Mr. Raup wrote code to program patterns on an automated loom for his wife, fiber artist Judith Yamamoto. They lived on Door County’s Washington Island.
In addition to his wife, Mr. Raup is survived by a son, Mitchell D. Raup; a stepson, David P. Topaz; and a grandson. Funeral arrangements, still pending, are being made through Casperson Funeral Home in Sister Bay, Wisconsin.