Whole-Earth Professor

By Heidi Aspaturian

It’s a bright winter day in Pasadena and up on the second floor of Caltech’s Arms Laboratory of the Geological Sciences, Joe Kirschvink ’75, MS ’75, is embracing a half-billion years of evolutionary history tightly enough to compress them into a 10-minute paleontology quiz. “All right, gang, what is it?” he asks a dozen students, holding up a fist-sized fossil. “Weird, floating plantlike things—anybody remember?” Everybody does—this is a Caltech crowd after all. Even the fossil has a faintly sapient air. “Okay, okay this one?” waving a new specimen. It turns out to be a casualty of the Permian extinction—the greatest mass dying in the history of life on Earth. Next comes a creature that unaccountably survived that catastrophe to become, as Kirschvink puts it, our “ancestral mammal.” It proves harder to identify, so Kirschvink helps out with a bit of show and tell.

“Imagine your vertebrate column coming down like this,” he urges his listeners, slinging his right arm across his left shoulder and wrestling it halfway down his back. “You can see . . .” The Caltech professor of geobiology seems to be hugging himself with delight.

Well, why not? Joe Kirschvink is on a roll. Nearly everyone who heard his American Geophysical Union (AGU) lecture suggesting that we are all descended from meteorite-hitching Martian bacteria wants to talk to him about it. He’s about to start a sabbatical at the University of Tokyo, joining his family who have lived in Japan for four years while he’s commuted regularly across the Pacific. He’s working with a group of “incredibly bright” graduate and undergraduate students on a host of topics whose names sound like the titles of lost novels by H. G. Wells: “True Polar Wander,” “Cambrian Explosion,” “Snowball Earth,” “Martian Panspermia.” To top it off, he’s just received Caltech’s most highly publicized salary increase, otherwise known as the Feynman Prize for Excellence in Teaching.

The eighth Feynman winner, Kirschvink was awarded $3,500 and will have a like amount immediately added to his base salary, in recognition of “his innovative teaching style and outstanding mentorship that have inspired a generation of Caltech students.” The Feynman Prize was endowed in 1992 by Caltech Associates Robert and Ione Paradise and has also benefited from the contributions of William and Sally Hurt.

“Professor Kirschvink’s classes attract a wide following of undergraduate and graduate students from all parts of campus,” said Caltech provost Steve Koonin ’72, who surprised Kirschvink with the announcement and check at an Institute faculty meeting in January. “These students are inspired by his unabashed enthusiasm for the Earth sciences, embraced by his sincerity and dedication to education, and challenged by the depth and breadth of his knowledge. The courses are a mix of fundamentals with state-of-the-art research and offer ample opportunity for fieldwork with outings in the U.S. and abroad. In addition, he has provided countless undergraduates with their first opportunities to do research and has patiently guided and developed them into first-rate scientists.”

Kirschvink is Caltech’s first undergraduate alum to win the Feynman Prize (Professor of Electrical Engineering and Computer Science Yaser Abu Mustafa, PhD ’83, received it in 1996), and he also has the distinction of being the first winner actually to have been taught by Feynman. As a sophomore, he attended the informal “Physics X” classes that the maestro held for undergraduates one evening a week in his Caltech office. Channeling physics through Feynman was of course exhilarating—“Oh, my God, he had the ability to make you think you understood it!”—but when the time came to choose his own major, Kirschvink opted for geology, influenced by the multidisciplinary directions the field was taking at Caltech and inspired by the diverse research agendas and classroom styles of professors like the late paleoecologist Heinz Lowenstam and geologist Robert Sharp ’34, MS ’35, his current colleague, mineralogist George Rossman, PhD ’71, and the late planetary scientist Eugene Shoemaker ’47, MS ’48. He earned his PhD at Princeton, then returned to campus in 1981 as the Institute’s first professor of geobiology.

Like his mentors, Kirschvink has cast a wide net in his research, which focuses on the interrelationship between biological evolution and geologic events on Earth and in the early solar system. He has carried out studies in paleomagnetism and biomagnetism, mass extinctions, evolutionary theory, continental tectonics, and microbial genetics, to name a few areas of interest. He is particularly well known for his research into the magnetic sensing abilities of animals ranging from honeybees to birds to whales, for the discovery that humans possess minute amounts of magnetic material in their brain tissues, and, more recently, for his “Snowball Earth” theory, which holds that Earth’s surface has frozen over several times in its history, with major consequences for the evolution of the biosphere. Originally considered highly controversial, if not downright odd, the theory has gained increasing acceptance and opened several new avenues of research. Kirschvink extended the model with his doctoral student David Evans, PhD ’98 (now a professor at Yale), one of numerous graduate and undergraduate students who have played an integral role in his research over the years.

“The bottom line is, Joe treats his students like colleagues,” says graduate student in planetary science Ben Weiss, who cowrote the letter nominating Kirschvink for the Feynman Prize with geobiology senior Tim Raub. “He involves them fully in his research, he gives them the confidence and the tools to recognize and attack original research problems on their own, and when they make discoveries, he stands aside to make sure they get the credit.”

As telling as this praise, says Weiss, was the enthusiastic response of the several former students—grad and undergrad—whom he and Raub enlisted to write letters supporting the nominee. “Everyone wanted to do it,” he says. “People were traveling, they were in the middle of research, and they all made time to do this for Joe.”

With such students and such subjects, says Kirschvink, who wouldn’t be a great teacher? “Science should be fun, it should be enjoyable,” he says, and the emergence of innovative multidis-ciplinary approaches to tackling “some of the really big questions that are out there” is a lure for students and professors alike. “Nature isn’t compartmentalized,” he says, echoing sentiments he expressed in a recent Japanese-language article, whose title he “loosely” translates as “Science is not a lunch box.”

“Nature didn’t create separate disciplines, or six divisions, or what have you. And science in the 21st century doesn’t need to either.”

Which brings us to “Mars, Panspermia, and the Origin of Life: Where Did It All Begin?” the talk that Kirschvink presented to a packed house when he delivered the Carl Sagan Memorial Lecture at the fall meeting of the American Geophysical Union last December. The talk is based on a paper of the same title that he and Weiss recently published in the online journal Palaeontologia Electronica. Using geo-chemical, thermal, and biological data drawn from such varied sources as Martian space missions, genome-sequence studies of microbial DNA, and the Martian meteorite ALH84001, which was recovered in Antarctica in 1984, the two conclude that conditions on the early earth may have been far less hospitable to the emergence of life than conditions on early Mars, and propose that primitive bacteria migrated via meteorites to Earth from the Red Planet.

The idea of panspermia as a solution to the vexing question of how life arose on Earth is not a new one—Nobel Laureate Francis Crick, among others, has advocated it, although Crick speaks in terms of sentient higher beings from who-knows-where deliberately seeding our planet. But only now, says Kirschvink, are investigative techniques into life’s origins advancing to the point where it’s possible to put forward plausible and testable scenarios—and right now the data point to Mars.

“So you see,” he says with a gleam in his eye, “that would explain our constant fascination with Mars. It’s our point of origin, our home planet.”

Joe Kirschvink, teacher, Feynman Prize winner, Martian. It has a ring.

Kirschvink’s Carl Sagan Memorial Lecture may be viewed online at http://jupiter.agu.org/webcast/kirsh.html, and will be presented again on the Caltech campus on June 3rd; see http://www.gps.caltech.edu/seminars/gps_seminars.html.