The Woeseian revolution was the progression of the phylogenetic

tree of life The tree of life is a fundamental archetype in many of the world's mythological, religious, and philosophical traditions. It is closely related to the concept of the sacred tree.Giovino, Mariana (2007). ''The Assyrian Sacred Tree: A Hist ...

concept from two main divisions, known as the Prokarya and

Eukarya Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bact ...

, into three domains now classified as

Bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

Archaea Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...

, and Eukaryotes. The discovery of the new domain stemmed from the work of biophysicist

Carl Woese 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, ...

in 1977 from a principle of evolutionary biology designated as Woese's dogma. It states that the evolution of

ribosomal RNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosom ...

(rRNA) was a necessary precursor to the evolution of modern life forms. Although the three-domain system has been widely accepted, the initial introduction of Woese’s discovery received criticism from the scientific community.

Phylogenetic implications

The basis of

phylogenetics In biology, phylogenetics (; from Greek language, Greek wikt:φυλή, φυλή/wikt:φῦλον, φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary his ...

was limited by the technology of the time, which led to a greater dependence on phenotypic classification prior to advances that would allow for molecular methods of organization. This was a major reason why the dichotomy of all living things, being either animal or plant in nature, was deemed as an acceptable theory. Without truly understanding the genetic implication of each organismal classification in phylogenies via nucleic acid sequencing of shared molecular material, the phylogenetic tree of life and other such phylogenies would no doubt be incorrect. Woese’s advances in molecular sequencing and phylogenetic organization allowed for a better understanding of the three domains of life - the Bacteria, Archaea, and Eukaryotes. In regards to their varying types of shared rRNA, that of the small subunit rRNA was deemed as the best molecules to sequence in order to distinguish phylogenetic relationships because of its relatively small size, ease of isolation, and universal distribution.

Controversy

This reorganization caused an initial pushback: it wasn't accepted until nearly a decade after its publication. Possible factors that led to initial criticisms of his discovery included Woese's

oligonucleotide Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics. Commonly made in the laboratory by solid-phase chemical synthesis, these small bits of nucleic acids ...

cataloging, of which he was one of "only two or three people in the world" to be able to execute this method, let alone read the films. Further, Woese's background was in physics, whereas most of the research was being done in the realm of microbiology.

Phylogenetic implications

Controversy

References

Further reading