We were saddened to learn of the passing of Carl Woese, world-renowned microbiologist and professor at the University of Illinois. He died at the age of 84, following a battle with Pancreatic cancer.

Woese was best known for his identification of the third domain of life, the Archaea (Woese and Fox, 1977; Balch et al., 1977; Woese et al., 1978; Woese et al., 1990). It was Carl Woese who first introduced phylogenetic taxonomy of 16S ribosomal RNA (Fox et al., 1977). He was also the first to propose, in his 1967 book The Genetic Code, RNA as the original genetic material, owing to its information-storage and catalytic properties — although the term “RNA world” was first coined in 1986 by Nobel laureate Walter Gilbert (Gilbert, 1986).

In 1997, the journal Science described him as “Microbiology’s Scarred Revolutionary.” Woese’s classification of life’s three domains was slow to be accepted, and it received criticism from prominent biologists such as Ernst Mayr (Mayr, 1998). As data supporting Woese’s classification mounted, however, the view of a unified Prokarya was virtually unanimously rejected.

Carl Woese also recognized the ubiquity of phylogenetic conflict across the tree of life, noting that “No consistent organismal phylogeny has emerged from the many individual protein phylogenies so far produced,” and that “Phylogenetic incongruities can be seen everywhere in the universal tree, from its root to the major branchings within and among the various taxa to the makeup of the primary groupings themselves” (Woese, 1998).

Like so many of science’s great pioneers, Carl Woese’s persistence in the face of criticism (which eventually won him the day) deserves to be emulated by aspiring young scientists. Never be afraid to think outside the paradigm, and be truly innovative.