Search results
Results from the WOW.Com Content Network
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 ...
[5] [6] The challenge for abiogenesis (origin of life) [7] [8] [9] researchers is to explain how such a complex and tightly interlinked system could develop by evolutionary steps, as at first sight all its parts are necessary to enable it to function. For example, a cell, whether the LUCA or in a modern organism, copies its DNA with the DNA ...
The junkyard tornado, sometimes known as Hoyle's fallacy, is a fallacious argument formulated by Fred Hoyle against Earth-based abiogenesis and in favor of panspermia.The junkyard tornado argument has been taken out of its original context by theists to argue for intelligent design, and has since become a mainstay in the rejection of evolution by religious groups, even though Fred Hoyle ...
According to one definition, a turn is a structural motif where the C α atoms of two residues separated by a few (usually 1 to 5) peptide bonds are close (less than 7 Å [0.70 nm]). [1] The proximity of the terminal C α atoms often correlates with formation of an inter main chain hydrogen bond between the corresponding residues. Such hydrogen ...
An RNA with a synthase or a synthetase activity could be critical for building compartments and providing building blocks for growing RNA and protein chains as well as other types of molecules. Many examples of this kind of ribozyme are currently known, including a peptidyl transferase ribozyme, [ 35 ] a ligase, [ 36 ] [ 37 ] and a nucleotide ...
One example is the acidophilic bacterial genus, A. ferrooxidans, that use iron(II) sulfide (FeS 2) to generate sulfuric acid. [29] The acidic product of these specific lithotrophs has the potential to drain from the mining area via water run-off and enter the environment.
Evidence of possibly the oldest forms of life on Earth has been found in hydrothermal vent precipitates. [1]The earliest known life forms on Earth may be as old as 4.1 billion years (or Ga) according to biologically fractionated graphite inside a single zircon grain in the Jack Hills range of Australia. [2]
In trying to uncover the intermediate stages of abiogenesis, scientist Sidney W. Fox in the 1950s and 1960s, studied the spontaneous formation of peptide structures under conditions that might plausibly have existed early in Earth's history. [3]: 199–201 He demonstrated that amino acids could spontaneously form small chains called peptides ...