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The RNA world is a hypothetical stage in the evolutionary history of life on Earth in which self-replicating RNA molecules proliferated before the evolution of DNA and proteins. [ 1 ] The term also refers to the hypothesis that posits the existence of this stage. Alexander Rich first proposed the concept of the RNA world in 1962, [ 2 ] and ...
In the late 1960s, Orgel proposed that life was based on RNA before it was based on DNA or proteins. His theory included genes based on RNA and RNA enzymes. [17] This view would be developed and shaped into the now widely accepted RNA world hypothesis. Almost thirty years later, Orgel wrote a lengthy review of the RNA World hypothesis. [18]
Last universal common ancestor. The last universal common ancestor (LUCA) is the hypothesized common ancestral cell from which the three domains of life, the Bacteria, the Archaea, and the Eukarya originated. The cell had a lipid bilayer; it possessed the genetic code and ribosomes which translated from DNA or RNA to proteins.
RNA can also act as a hereditary molecule, which encouraged Walter Gilbert to propose that in the distant past, the cell used RNA as both the genetic material and the structural and catalytic molecule rather than dividing these functions between DNA and protein as they are today; this hypothesis is known as the "RNA world hypothesis" of the ...
The RNA world hypothesis describes an early Earth with self-replicating and catalytic RNA but no DNA or proteins. [172] Many researchers concur that an RNA world must have preceded the DNA-based life that now dominates. [173] However, RNA-based life may not have been the first to exist.
RNP world. The RNP world is a hypothesized intermediate period in the origin of life characterized by the existence of ribonucleoproteins. [1] The period followed the hypothesized RNA world and ended with the formation of DNA and contemporary proteins. [2] In the RNP world, RNA molecules began to synthesize peptides.
Carl Richard Dick Woese (/ ˈwoʊz /; [3] 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. [4][5][6][7] He also originated ...
Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyribonucleic acid (DNA) are nucleic acids. The nucleic acids constitute one of the four major ...