Last modified: Wednesday, March 30, 2011
Curtis M. Lively
Distinguished Professor of Biology
Department of Biology
College of Arts and Sciences
University Graduate School
Indiana University Bloomington
Appointed to IU faculty, 1990
B.S., Arizona State University, 1977
Ph.D., University of Arizona, 1984
". . . it takes all the running you can do to stay in the same place."
—The Red Queen in Through the Looking Glass by Lewis Carroll
Why there should be two sexes in humans, three sexes in some plants, and dozens of sexes in certain fungus species is an important question in evolutionary biology. A dozen explanations have come and gone. One perseveres—the Red Queen Hypothesis. IU Bloomington evolutionary biologist Curtis Lively was the first to provide hard, scientific evidence in support of the University of Chicago's Leigh Van Valen's 1973 hypothesis, which argues that in a changing and challenging environment, species must continually evolve and adapt if the members of that species are merely to maintain their present evolutionary fitness.
As a postdoctoral fellow at the University of Canterbury in Christchurch, New Zealand, Lively reported in a 1987 letter to the journal Nature that parasitism can maintain the usefulness of sexual reproduction in a species of New Zealand snail. The snail, Potamopyrgus antipodarum, can reproduce sexually or asexually. Lively found that the frequency of the production of males (the variant sex) was tightly tied to the strength of parasitism, with highly infected populations producing the most males. The implication was that the existence of two sexes presents parasite species with a sort of moving target—parasites tend to specialize in infecting one physiology, and adapt to the everchanging defenses of one type of physiology. Both host and parasite must continually adapt—continually run alongside the Red Queen—to survive.
In 1990, Lively wrote another letter to Nature, this time with Rutgers University colleagues Clark Craddock and Robert Vrijenhoek, reporting that parasite infection tends to be highest in clonal populations, rather than in sexual populations where genetic diversity is highest. "Curt has also made important theoretical contributions to our understanding of genetic interactions between hosts and their pathogens," says former president of the American Society of Naturalists and University of Virginia Lewis and Clark Professor of Biology Janis Antonovics. "In a field that has been excessively dominated by theory or qualitative arguments, his rigorous empirical studies shine through and have become the examples that textbooks use to illustrate the role of pathogens in the evolution of sex."
Professor Paul B. Rainey of the New Zealand Institute for Advanced Study at Massey University agrees, saying, "In all regards and in all respects, Curt's contributions are outstanding: his work is published in the most esteemed journals, it is highly cited, it is of broad significance. . . . It is inspirational."
Lively, who combines his faculty position at IU with duties as a senior adjunct researcher at the New Zealand Institute for Advanced Study in Auckland, has authored or co-authored more than 100 peer-reviewed publications on a wide variety of subjects in evolutionary biology, a common theme being the ecology and evolutionary implications of host-parasite interactions.
Lively's study of Potamopyrgus and its trematode parasite now spans nearly 30 years. In 2009, he, IU Professor of Biology Lynda Delph, and ETH-Zurich biologist (and former Lively lab postdoctoral fellow) Jukka Jokela oversaw a project by IU Ph.D. student Kayla King, who showed that Potamopyrgus females were choosing asexual reproduction within a few meters of females choosing sexual reproduction. King, lead author of the paper and a member of Lively's lab, reported that the tension between sexual and asexual reproduction is vibrant and dynamic, and can be manifest as "hot spots" of sexual reproduction where parasites are common, or cold spots of asexual reproduction where parasites are rare, across a depth gradient within a single population of snails.
Because he is such a dedicated educator, spots in Lively's lab are in demand. He has been an advisor to ten Ph.D. and five M.S. graduates, and currently advises four Ph.D. candidates, including King. Lively has also overseen projects by more than three dozen undergraduates as part of the Department of Biology's Independent Research Program. He received Teaching Excellence Recognition Awards in 1997, 1999, and 2000; the Senior Class Award for Teaching Excellence and Dedication to Undergraduates in 2000 and 2002; and the IU Trustees' Award for Outstanding Teaching in 2002. He received the Mercer Award from the Ecological Society of America in 1987, was a Jack Gill Fellow from 1997 to 2001, and was elected a fellow of the American Association for the Advancement of Science (AAAS) in 2004 and an honorary fellow of the Royal Society of New Zealand in 2007. Lively served as vice president for the Society for the Study of Evolution (SSE) in 2003. Dieter Ebert, professor of biology at the Zoological Institute of the University of Basel, Switzerland, notes that Lively has "had a lasting impact on the entire field, and his works in the field have become classics."