Nov. 9, 1995
Vol. 15, No. 5

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    Kidwell wins top paleontology award

    for studies on decaying organisms Plus sidebar: U of C leader in Schuchert Award When Susan Kidwell, Professor in Geophysical Sciences, is asked about her research, she smiles. "When I tell people what I do, there's a wide variety of reactions -- some people are intrigued, some people laugh, and the rest are really grossed out," she said. "The truth is, I study post-mortem processes, what happens to an organism after it dies."

    As unusual as it may sound, Kidwell's research, in the field known as "taphonomy," is critically important to paleontology. In recognition of her innovative contributions to the field, Kidwell has been presented with the 1995 Schuchert Award of the Paleontological Society. This international award is given annually to an outstanding young paleontologist; Kidwell is the sixth Chicago faculty member to receive the prize (see sidebar).

    Post-mortem processes -- the decomposition of soft parts, or the transport of skeletal remains out of the habitat in which the organism lived (the washing of bones down a stream, for example) -- affect what appears in the fossil record, Kidwell explained. Knowing more about what happens to an organism as it dies, decomposes and is fossilized helps scientists gauge the validity of patterns detected in the fossil record.

    "Taphonomists develop methods to estimate how paleontologic data might be biased by the process of fossilization," Kidwell said. "For example, selective destruction of various groups of organisms -- jellyfish are not as preservable as clams, for example -- determines their ultimate distribution and abundance as fossils.

    "More insidious is bias due to the mixing of remains of different ages," she added. "The bones and shells from different generations of organisms can come to lie in a single geological stratum -- just as in human graveyards many generations of people can be buried at the same level even though they didn't all live at the same time. A paleontologist doesn't have a gravestone to tell the time of death, so we have to reconstruct this from indirect clues."

    The methods of a taphonomist are diverse. Kidwell conducts comparative studies both in the field and in the lab to find out how bias is actually distributed and therefore how it might be factored out.

    "I like taphonomy because it is the paleontological equivalent of historiography -- rather than history itself, it's how history is recorded. We look between the lines of history to find out to what extent we can take the fossil record at face value," she said. "I also like it because it spans so many fields -- biology, geology, geochemistry."

    Experiments by Kidwell and students include sea urchins rotting in her lab, bones bleaching on the roof of Hinds Laboratory and strings of clam shells buried in the shifting coastal sands of Panama to determine the rate and sequence of post-mortem processes. With the Panama experiment, for example, Kidwell and graduate student Mairi Best are tracking the rate of shell breakdown in tropical seas and patterns of shell accumulation. These studies of modern organisms will provide a baseline for biodiversity patterns across latitudinal zones over geologic time.

    Kidwell also goes directly to the geologic record to examine systematically such variables as total elapsed geologic time, geochemical environment and climate. She has focused on a relatively recent slice of time, the last 25 million years, but is now testing for patterns over a much larger span, the last 600 million years. Somewhat counterintuitively, at least some aspects of the fossil record actually improve as you go further back in time, she said.

    "There has been tremendous evolution on the supply side of the equation -- the organisms that produce potential fossils -- but also among agents of destruction, those organisms that destroy bones and shells," she said. "The bottom line turns out to be that life after death has gotten more difficult over geologic time. Half a billion years ago, post-mortem processes were less severe but shells were also less durable, with the result that the mixing of multiple generations is less of a problem."

    Kidwell received her B.S. in geology in 1976 from the College of William and Mary and received her Ph.D. in 1982 in geology from Yale. She was assistant professor at the University of Arizona from 1981 to 1985, when she joined the Chicago faculty as Assistant Professor in Geophysical Sciences and the Committee on Evolutionary Biology. She became Associate Professor in 1988 and Professor in 1994.

    In addition to teaching and conducting research, Kidwell serves as chair of the Provost's Task Force on the Quality of Student Experience. She also is a member of the Earth Sciences Board of the National Research Council, which advises the federal government on science and science policy.

    Because taphonomy is such a young and growing field, and because it draws on so many other disciplines, Kidwell finds Chicago an especially stimulating environment in which to work.

    "What I love about Chicago is the interaction with people doing such a wide variety of work -- paleobiologists, paleogeographers, paleoclimatologists, atmospheric scientists and chemical oceanographers."

    Kidwell also cited the diversity of research in the interdisciplinary Committee on Evolutionary Biology, which spans not only departments but divisions (Physical Sciences, Biological Sciences and Social Sciences) and institutions (the University, the Field Museum and Brookfield Zoo).

    "All of these interactions combine to make this the foremost paleontology program in the country," Kidwell said. "That's why so many superb students vote with their feet to come to Chicago.

    "In fact, more than the number of Schuchert awardees on our faculty, the best measure of the program is the success our students have met with professionally," Kidwell added. "They go on to great jobs and are having a real impact on the field. Being involved in this program gives rewards every day."

    -- Diana Steele U of C leader in Schuchert Award The Nobel Prize isn't the only award that has become nearly synonymous with the University -- the Schuchert Award of the Paleontological Society has been awarded to more faculty members at Chicago than at any other institution in the country.

    Given annually to recognize excellence by a young paleontologist, usually under age 40, the award is the premier international prize of the Paleontological Society. In its 22-year history, the award has been presented to a faculty member at Chicago six times -- more times than to faculty members of the other major paleontology programs at Harvard, Yale, Berkeley and the University of Michigan combined.

    The first Schuchert Award was presented in 1973 to David Raup, the Sewell L. Avery Distinguished Service Professor Emeritus in Geophysical Sciences. In 1976, the award went to Thomas Schopf, Professor in Geophysical Sciences, who died in 1984. Chicago also has four recipients -- also more than any of the other top-ranked paleontology programs in the country -- who currently teach on the faculty: J. John "Jack" Sepkoski Jr. (1983), David Jablonski (1988), Peter Crane, who is also vice president of the Field Museum (1993), and this year's recipient, Susan Kidwell. All four faculty members are Professors in Geophysical Sciences and also teach in the Committee on Evolutionary Biology and in the College.