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The structure of the ribosome has been called the "smoking gun", with a central core of RNA and no amino acid side chains within 18 Å of the active site that catalyzes peptide bond formation. [189] [184] [190] The concept of the RNA world was proposed in 1962 by Alexander Rich, [191] and the term was coined by Walter Gilbert in 1986.
A scenario is a set of related concepts pertinent to the origin of life (abiogenesis), such as the iron-sulfur world. Many alternative abiogenesis scenarios have been proposed by scientists in a variety of fields from the 1950s onwards in an attempt to explain how the complex mechanisms of life could have come into existence. These include ...
UV exposure has also been shown to promote the synthesis of stable biomolecules like nucleotides. [55] [56] In the origin of chemiosmosis, if early cells originated at alkaline hydrothermal vents, proton gradients can be maintained by the acidic ocean and alkaline water from white smokers while an inorganic membranous structure is in a rock cavity.
Bernal called this idea biopoiesis or biopoesis, the process of living matter evolving from self-replicating but non-living molecules, [17] [31] and proposed that biopoiesis passes through a number of intermediate stages. Robert Shapiro has summarized the "primordial soup" theory of Oparin and Haldane in its "mature form" as follows: [32]
The eukaryotic cell seems to have evolved from a symbiotic community of prokaryotic cells. DNA-bearing organelles like mitochondria and chloroplasts are remnants of ancient symbiotic oxygen-breathing bacteria and cyanobacteria, respectively, where at least part of the rest of the cell may have been derived from an ancestral archaean prokaryote ...
Kidney and nerve tissue cells can form memories much like brain cells, one new study has found. Another recent study says that memories of obesity stored in fat tissue may be partly responsible ...
A proto-metabolism is a series of linked chemical reactions in a prebiotic environment that preceded and eventually turned into modern metabolism.Combining ongoing research in astrobiology and prebiotic chemistry, work in this area focuses on reconstructing the connections between potential metabolic processes that may have occurred in early Earth conditions. [1]
Pasteur's claim followed the German physician Rudolf Virchow's doctrine Omnis cellula e cellula ("all cells from cells"), [49] itself derived from the work of Robert Remak. [50] [38] After Pasteur's 1859 experiment, the term "spontaneous generation" fell out of favor. Experimentalists used a variety of terms for the study of the origin of life ...