1. Exobiology Pioneer Carl Woese: 1928-2012

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    Biophysicist and evolutionary microbiologist Carl R. Woese died December 30 following complications from pancreatic cancer. He was 84.

    Dr. Woese – a professor of microbiology with the School of Molecular and Cellular Biology and the Institute for Genomic Biology at the University of Illinois-Urbana at the time of his death – is as well known outside the astrobiology community as he is inside it for his identification of a previously unknown “third domain” of life, the archaea, which he and his colleagues reported in the Proceedings of the National Academy of Sciences in 1977 1. NASA’s Exobiology Program issued its first grant to Woese in 1975.

    Historians have called Woese et al’s finding “one of the most remarkable discoveries of 20th century biology.” 2

    The Institute for Genomic Biology said in an announcement of his death:

    Carl was truly a man of vision, creativity and passion, with a deep love of this university. He enjoyed deep respect from all who were fortunate to interact with him. He not only rewrote the textbook in evolutionary biology, but his discovery has given us the tools today to study the human microbiome…in ways that we’re only beginning to understand. Carl Woese was one of the most significant biologists of the 20th century…

    Dr. Woese received a B.A. in math and physics from Amherst College (1950) and a Ph.D. in Biophysics from Yale University (1953). He conducted postdoctoral research in biophysics at Yale from 1953-1960, continued his research at General Electric Research Laboratory from 1960-1963, and in 1964 joined the faculty of the University of Illinois-Urbana, where he remained for the rest of his career.

    On his Web site, Dr. Woese identified his research interests as archaea, genomics, and molecular evolution and his teaching interests as the molecular evolution of prokaryotes and the structure-function of protein translation apparatus. “I am a molecular biologist turned evolutionist,” Woese wrote:

    My evolutionary concerns center on the bacteria and the archaea, whose evolutions cover most of the planet’s 4.5-billion-year history. Using ribosomal RNA sequence as an evolutionary measure, my laboratory has reconstructed the phylogeny of both groups, and thereby provided a phylogenetically valid system of classification for prokaryotes. The discovery of the archaea was in fact a product of these studies.

    The archaea are unique organisms. While prokaryotes in the cytological sense, they are actually more closely related to eukaryotes than to the bacteria. They are of particular interest for this reason alone – they are simple organisms whose study should provide insights into the nature and evolution of the eukaryotic cell. Their study is also central to an understanding of the nature of the ancestor common to all life. The archaea are, of course, interesting in their own right. The group contains both the methanogens and numerous organisms that grow at extremely high temperatures (in some cases above 100°C). As such, they provide potential insights into mechanisms of thermophilia and methanogenesis.

    My [recent] work…has centered on genomic analysis, with an emphasis on understanding the evolutionary significance of the phenomenon of horizontal gene transfer (HGT)…. The ultimate goal is to construct a model (theory) of how the primary cell types (the archaeal, eubacterial, and eukaryotic) have evolved, from some ancestral state in the RNA-world.

    In the later years of his career Dr. Woese grew passionate about the future of microbiology, offering his views on the subject in a variety of venues, including Microbiology and Molecular Biology Reviews3:

    Biology today is at a crossroads. The molecular paradigm, which so successfully guided the discipline throughout most of the 20th century, is no longer a reliable guide. Its vision of biology now realized, the molecular paradigm has run its course. Biology, therefore, has a choice to make, between the comfortable path of continuing to follow molecular biology’s lead or the more invigorating one of seeking a new and inspiring vision of the living world, one that addresses the major problems in biology that 20th century biology, molecular biology, could not handle and, so, avoided. The former course, though highly productive, is certain to turn biology into an engineering discipline. The latter holds the promise of making biology an even more fundamental science, one that, along with physics, probes and defines the nature of reality. This is a choice between a biology that solely does society’s bidding and a biology that is society’s teacher.

    Dr. Woese was the author or co-author of 191 papers in molecular biology and biophysics. He received a MacArthur Foundation Fellowship in 1984, the Leeuwenhoek Medal in 1992, the Selman A. Waksman Award in Microbiology in 1995, and the National Medal of Science and the Crafoord Prize in Biosciences in 2003. He was elected to the National Academy of Sciences in 1988 and to The Royal Society (as a foreign member) in 2006.

    (1) C.R. Woese and G.E. Fox, Phylogenetic structure of the prokaryotic domains: the primary kingdoms, PNAS 74 (11), November 2007.
    (2) Steven Dick and James Strick, The Living Universe: NASA and the Development of Astrobiology, Rutgers University Press, 2004.
    (3) C.R. Woese, A New Biology for a New Century, MMBR., June 68(2):173–86, 2004.