According to the New York Times Carl Woese (1928-2012) died at home in Urbana Illinois on Sunday.
Although I imagine that many if not most of you will have never heard of Prof. Woese he made perhaps the most important discoveries concerning the diversity and history of life on earth of the last century. Follow below the fold to learn a bit more.
The description on his web page (at least at the time I worked at the U of I) said he was a microbiologist turned evolutionist. Woese took a faculty position at the University of Illinois almost 50 years ago. He developed an interest in working out the evolutionary relationships among different groups of prokaryotic organisms (i.e. bacteria). This was very much a black box at the time as bacteria could be classified by shape (cocci, bacilli, etc.) and by their reaction to certain chemicals. Information was simply not available to develop an idea about the evolutionary relationships among different types of bacteria.
Woese, using the relatively primitive techniques of the era collected molecular data on a range of bacterial species. What he discovered was surprising and, at least for a time, quite controversial. Up to that time, cellular organisms had been classified as prokaryotes (cells without nuclei) and eukaryotes (cells with nuclei). Woese discovered that the prokaryotes formed two distinct groups which eventually were named the Bacteria and Archaea. The Archaea are more closely related to to eukaryotic life (e.g. animals, plants, fungi) than they are to Bacteria.
Woese used his discovery to develop the concept of the Three Domains of Life. These domains are the Bacteria, Archaea, and Eukarya. This was a dramatic change from the predominant five kingdom classification scheme of the time which recognized four kingdoms of eukaryotic life and lumped all the prokaryotes into a single kingdom. The Three Domains were introduced in the 1970s and remained controversial until around 1990 or so. Woese went from a fringe figure to someone whose work was prominently featured in major textbooks and who won the Crafoord Prize which is often referred to as the Nobel for Ecology and Evolutionary Biology.
The switch to three domains from five kingdoms is a switch from a progressive view of evolution in which microorganisms are primitive sidelines to one in which they are the primary players in the history of life on earth.
In addition to this discovery Woese was one of, if not the first to use molecular data in systematic research (the study of evolutionary relationships). In the late 1980s the use of DNA data to work on phylogenies (evolutionary trees) became widespread. Our understanding of evolutionary history has expanded exponentially as a result.
I never spoke to Woese when I worked at the U of I. He was in a different academic unit. His home was on my way to work and I would occasionally see him walking ahead of me in one of his ubiquitous flannel shirts.