Carl Woese - WikiHQ

Carl Richard Woese ( ; July 15, 1928 – December 30, 2012) was an American microbiologist and biophysicist. Woese is famous for defining the Archaea (a new domain of life) in 1977 through a pioneering phylogenetic taxonomy of 16S ribosomal RNA, a technique that has revolutionized microbiology. Woese held the Stanley O. Ikenberry Chair and was professor of microbiology at the University of Illinois Urbana–Champaign.

Life and education

Woese was born in Syracuse, New York on July 15, 1928. His family was German American. Woese attended Deerfield Academy in Massachusetts. He received a bachelor's degree in mathematics and physics from Amherst College in 1950. During his time at Amherst, Woese took only one biology course (Biochemistry, in his senior year) and had "no scientific interest in plants and animals" until advised by William M. Fairbank, then an assistant professor of physics at Amherst, to pursue biophysics at Yale.

In 1953, he completed a PhD in biophysics at Yale University, where his doctoral research focused on the inactivation of viruses by heat and ionizing radiation. Then he became a postdoctoral researcher in biophysics at Yale University investigating bacterial spores. From 1960 to 1963, he worked as a biophysicist at the General Electric Research Laboratory in Schenectady, New York. In 1964, Woese joined the microbiology faculty of the University of Illinois Urbana–Champaign, where he focused on Archaea, genomics, and molecular evolution as his areas of expertise.

Work and discoveries

Early work on the genetic code

Woese turned his attention to the genetic code while setting up his lab at General Electric's Knolls Laboratory in the fall of 1960. He then re-evaluated experimental data associated with the hypothesis that viruses used one base, rather than a triplet, to encode each amino acid, and suggested 18 codons, correctly predicting one for proline. Other work established the mechanistic basis of protein translation, but in Woese's view, largely overlooked the genetic code's evolutionary origins as an afterthought.

Discovery of the third domain

For much of the 20th century, prokaryotes were regarded as a single group of organisms and classified based on their biochemistry, morphology and metabolism. In a highly influential 1962 paper, Roger Stanier and C. B. van Niel first established the division of cellular organization into prokaryotes and eukaryotes, defining prokaryotes as those organisms lacking a cell nucleus. Adapted from Édouard Chatton's generalization, Stanier and Van Niel's concept was quickly accepted as the most important distinction among organisms; yet they were nevertheless skeptical of microbiologists' attempts to construct a natural phylogenetic classification of bacteria. However, it became generally assumed that all life shared a common prokaryotic (implied by the Greek root πρό (pro-), before, in front of) ancestor.

In 1977, Woese and George E. Fox experimentally disproved this universally held hypothesis about the basic structure of the tree of life. Not all criticism of him was restricted to the scientific level. A decade of labor-intensive oligonucleotide cataloging left him with a reputation as "a crank," and Woese would go on to be dubbed as "Microbiology's Scarred Revolutionary" by a news article printed in the journal Science. The growing body of supporting data led the scientific community to accept the Archaea by the mid-1980s. Organisms similar to those archaea that exist in extreme environments may have developed on other planets, some of which harbor conditions conducive to extremophile life.

Notably, Woese's elucidation of the tree of life shows the diversity of microbial lineages: single-celled organisms represent the vast majority of the biosphere's genetic, metabolic, and ecologic niche diversity. As microbes are crucial for biogeochemical cycles and to the continued function of the biosphere, Woese's research on how microbes evolve and their different types has provided data used by ecologists and conservationists. It was a major contribution to the theory of evolution and to our knowledge of the history of life.

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". First described by Woese and Fox in a 1977 paper and explored further with microbiologist Jane Gibson in a 1980 paper, these organisms, or progenotes, were imagined as protocells with very low complexity due to their error-prone translation apparatus ("noisy genetic transmission channel"), which produced high mutation rates that limited the specificity of cellular interaction and the size of the genome. This early translation apparatus would have produced a group of structurally similar, functionally equivalent proteins, rather than a single protein.

The transition to modern cells (the "Darwinian Threshold") occurred when organisms evolved translation mechanisms with modern levels of fidelity: improved performance allowed cellular organization to reach a level of complexity and connectedness that made genes from other organisms much less able to displace an individual's own genes. He worked on detailed analyses of the phylogenies of the aminoacyl-tRNA synthetases and on the effect of horizontal gene transfer on the distribution of those key enzymes among organisms. The goal of the research was to explain how the primary cell types (the archaeal, eubacterial, and eukaryotic) evolved from an ancestral state in the RNA world. and was a National Medal of Science recipient in 2000. In 2003, he received the Crafoord Prize from the Royal Swedish Academy of Sciences "for his discovery of a third domain of life". He was elected to the American Philosophical Society in 2004. In 2006, he was made a foreign member of the Royal Society. Methanobrevibacter woesei, and Conexibacter woesei, are named in his honor.

Microbiologist Justin Sonnenburg of Stanford University said "The 1977 paper is one of the most influential in microbiology and arguably, all of biology. It ranks with the works of Watson and Crick and Darwin, providing an evolutionary framework for the incredible diversity of the microbial world".

Selected publications

Books

Selected articles

References

External links

Carl Woese papers at the University of Illinois, Champaign
The Carl R. Woese Institute for Genomic Biology, University of Illinois
Woese's Homepage, Carl R. Woese Institute for Genomic Biology, November 30, 2017
Carl R. Woese Guestbook, Carl R. Woese Institute for Genomic Biology, November 30, 2017
Excerpts from a documentary on Woese's Tree of Life