Who is carl woese

Until that time, biologists had taken for granted that all life on Earth belonged to one of two primary lineages, the eukaryotes which include animals, plants, fungi and certain unicellular organisms such as paramecium and the prokaryotes all remaining microscopic organisms. Woese discovered that there were actually three primary lineages. Within what had previously been called prokaryotes, there exist two distinct groups of organisms no more related to one another than they were to eukaryotes. The new group of organisms — the Archaea — was initially thought to exist only in extreme environments, niches devoid of oxygen and whose temperatures can be near or above the normal boiling point of water.

Microbiologists later realized that Archaea are a large and diverse group of organisms that are widely distributed in nature and are common in much less extreme habitats, such as soils and oceans. As such, they are significant contributors to the global carbon and nitrogen cycles. These techniques have also revolutionized ecology, because it is now possible to survey an ecosystem by collecting ribosomal DNA from the environment, thus sidestepping the often impossible task of culturing the organisms that are there.

These microorganisms and the revolutionary methods that Woese introduced into science can offer insights into the nature and evolution of cells. In , Woese and colleagues University of Illinois professor Gary Olsen and researchers from the Institute for Genomic Research published in the journal Science the first complete genome structure of an archaeon, Methanococcus jannaschii.

Based on this work, they concluded that the Archaea are more closely related to humans than to bacteria. At such a time, the standard population genetics theory of evolution would not be applicable. Woese articulated early clear proposals about the nature of what has come to be known as the last universal common ancestor, concluding for a variety of reasons that the universal ancestor was not a single organism, but rather groupings of loosely structured cells that existed together during a time when genetic mutation rates were high and the transfer of genes between cells occurred more frequently than in the present day.

This created a Piet Mondrian-esque masterpiece of black bands on a white background. Each different organism left its own mark. After developing each image, Woese and Fox returned to the gel and neatly cut out each individual blotch that contained fragments of a certain length.

They then chopped up these fragments with another set of enzymes until they were about five to 15 nucleotides long, a length that made sequencing easier. For some of the longer fragments, it took several iterations of the process before they were successfully sequenced. The sequences were then recorded on a set of column IBM punch cards.

The cards were then run through a large computer to compare band patterns and RNA sequences among different organisms to determine evolutionary relationships. At the time, the field was just a total disaster area. Nobody knew what the hell was going on. RNA is so fundamental to life that some scientists think it's the spark that started it all. By the spring of , Woese and Fox had created fingerprints of a variety of bacterial species when they turned to an oddball group of prokaryotes: methanogens.

These microbes produce methane when they break down food for energy. Because even tiny amounts of oxygen are toxic to these prokaryotes, Woese and Fox had to grow them under special conditions.

After months of trial and error, the two scientists were finally able to obtain an RNA fingerprint of one type of methanogen. When they finally analyzed its fingerprint, however, it looked nothing like any of the other bacteria Woese and Fox had previously analyzed. All of the previous bacterial gels contained two large splotches at the bottom. They were entirely absent from these new gels.

Woese knew instantly what this meant. He dropped the full bombshell on Fox. The methanogens Woese and Fox had analyzed looked superficially like other bacteria, yet their RNA told a different story, sharing more in common with nucleus-containing eukaryotes than with other bacteria. To prove to their critics that these prokaryotes really were a separate domain on the tree of life, Woese and Fox knew the branch needed more than just methanogens.

For one thing, their cell walls lacked a mesh-like outer layer made of peptidoglycan. Nearly every other bacterium Fox could think of contained peptidoglycan in its cell wall—until he recalled a strange fact he had learned as a graduate student—another group of prokaryotes, the salt-loving halophiles, also lacked peptidoglycan. Fox turned to the research literature to search for other references to prokaryotes that lack peptidoglycan. He found two additional examples: Thermoplasma and Sulfolobus.

Other than the missing peptidoglycan, these organisms and the methanogens seemed nothing alike. Methanogens were found everywhere from wetlands to the digestive tracts, halophiles flourished in salt, Thermoplasma liked things really hot, and Sulfolobus are often found in volcanoes and hot, acidic springs. Despite their apparent differences, they all metabolized food in the same, unusual way—unlike anything seen in other bacteria—and the fats in the cell membrane were alike, too.

Woese, who died on 30 December, was born in Syracuse in New York in His undergraduate education was in physics and mathematics at Amherst College in Massachusetts. After taking up a research position at the General Electric Research Laboratory in Schenectady, New York, Woese began thinking about the evolution of the genetic code.

In , the molecular biologist Sol Spiegelman recruited him to the microbiology department at the University of Illinois in Urbana, where he spent his entire academic career. At Illinois, Woese examined the nucleotide sequences of 5S ribosomal RNA a component of ribosomes, which build proteins from different organisms. He quickly realized that ribosomal RNA is an ideal chronometer for measuring evolutionary distances between living things. It has a slow mutation rate, performs an identical function in all organisms and, because ribosomal RNA interacts specifically with a multitude of proteins, the genes encoding it are unlikely to jump between individuals of different species.

Woese had discovered a window into microbial phylogeny. Until this point, the field had been hopelessly muddy, with identifications of microorganisms based on qualitative characteristics such as differences in shape. In the early s, Woese realized that the sequence of 5S ribosomal RNA contained too few nucleotides to provide a way to classify thousands of organisms.

This led him to take on the daunting task of analysing 16S ribosomal RNA, which contains more than 1, nucleotides. Woese began sequencing fragments of 16S ribosomal RNA from every microorganism that he could get his hands on, using RNA 'fingerprinting' — a method developed by British biochemist Fred Sanger. The technique involves separating fragments of RNA in an electric field according to their nucleotide compositions. Woese's enormous undertaking, which involved analysing more than organisms and spanned many years, paid off richly.

One day, the analysis of 16S RNA from a methane-producing organism gave an astonishing result. Woese, presented a novel tool to use molecular data for the reconstruction of microbial relationships. By using ribosomal RNA — an essential component of a cell's protein making machinery — they demonstrated that it was possible to identify and classify microbes by intrinsic characteristics of their biological sequences.

The paper marked the birth of molecular phylogeny, a technique that would soon revolutionize studies in the realms of microbiology and evolution. A result of this first analysis was the discovery of a third domain of life — the Archaea — which are no less different to Bacteria than to the Eucarya, the branch that includes all "higher" forms of life such as plants or animals.