In On the Origin of Species, he had referred to life having been "created", by which he "really meant 'appeared' by some wholly unknown process", but had soon regretted using the Old Testament term "creation". The term biogenesis is usually credited to either Henry Bastian or to Thomas Huxley.

The choice seems simple: either show how a structured, regular world could arise out of undirected processes, or inject intelligence into the system. [211] The variables of the Drake equation are used to discuss the conditions in planetary systems where civilization is most likely to exist. [221] Hence, fossils range in age from the youngest at the start of the Holocene Epoch to the oldest from the Archaean Eon, up to 3.4 billion years old. "[363] The data suggest that viruses originated from ancient cells that co-existed with the ancestors of modern cells. Specifically, he identified the "nonfractionability of components in an organism" as the fundamental difference between living systems and "biological machines. England’s theoretical results are generally considered valid. Such systems are also error correcting[337] and chiroselective.[338]. Iron-sulfur surfaces, which are abundant near hydrothermal vents, are also capable of producing small amounts of amino acids and other biological metabolites.[47]. Onsager, L. (1931) Reciprocal Relations in Irreversible Processes I and II, Prigogine, I. As England put it, “A great way of dissipating more is to make more copies of yourself.” In a September paper in the Journal of Chemical Physics, he reported the theoretical minimum amount of dissipation that can occur during the self-replication of RNA molecules and bacterial cells, and showed that it is very close to the actual amounts these systems dissipate when replicating. [165], There is no single generally accepted model for the origin of life. In more complex organisms, coordination of activities can occur through a dedicated nervous system.[204].

“This connects very much to what Jeremy is saying,” Brenner said. Furthermore, the polymerization of the amino acid thioesters into polypeptides preceded the directed polymerization of amino acid esters by polynucleotides. In Rhythmic and Synthetic Processes in Growth, ed. [32][33] Thermodynamically, life has been described as an open system which makes use of gradients in its surroundings to create imperfect copies of itself. Aristotle is considered to be the first person to classify organisms. The other primary type of cells are the eukaryotes, which have distinct nuclei bound by a nuclear membrane and membrane-bound organelles, including mitochondria, chloroplasts, lysosomes, rough and smooth endoplasmic reticulum, and vacuoles.

[64], whereas according to Neil Campbell and Jane Reece, The phenomenon we call life defies a simple, one-sentence definition.[65]. It is his interpretation — that his formula represents the driving force behind a class of phenomena in nature that includes life — that remains unproven. DNA stores biological information. In 2010, based on spectral analysis of sea and hot mineral water, Ignat Ignatov and Oleg Mosin demonstrated that life may have predominantly originated in hot mineral water.

[95][96][97] Evidence suggests that life on Earth has existed for at least 3.5 billion years,[98][99][100][101][102][103][104][105][106] with the oldest physical traces of life dating back 3.7 billion years;[107][108][109] however, some theories, such as the Late Heavy Bombardment theory, suggest that life on Earth may have started even earlier, as early as 4.1–4.4 billion years ago,[98][99][100][101][102] and the chemistry leading to life may have begun shortly after the Big Bang, 13.8 billion years ago, during an epoch when the universe was only 10–17 million years old. Life, particularly simple forms, spontaneously and readily arises from nonliving matter in short periods of time, today as in the past. Under the oxygen depleted, CO2-dominated primordial atmosphere, the chemistry of water condensates and exhalations near geothermal fields would resemble the internal milieu of modern cells. [195] Cells contain hereditary information that is carried forward as a genetic code during cell division. But the behavior of systems that are far from equilibrium, which are connected to the outside environment and strongly driven by external sources of energy, could not be predicted. They are also logical precursors in the synthesis of such key biochemical compounds as adenosine triphosphate (ATP). [137][138][139][140], In March 2015, NASA scientists reported that, for the first time, complex DNA and RNA organic compounds of life, including uracil, cytosine and thymine, have been formed in the laboratory under outer space conditions, using starting chemicals, such as pyrimidine, found in meteorites. [48], Computer simulations also suggest that cavitation in primordial water reservoirs such as breaking sea waves, streams and oceans can potentially lead to the synthesis of biogenic compounds. But if (and oh! This Second Law of thermodynamics needs to be considered when self-organization of matter to higher complexity happens. [241] The researchers used the term "cyanosulfidic" to describe this network of reactions. For example, heat (such as from geothermal processes) is a standard energy source for chemistry. [67], Albert Lehninger has stated around 1970 that fermentation, including glycolysis, is a suitable primitive energy source for the origin of life.[68]. The individual members of a colony are capable of surviving on their own, whereas the members of a true multi-cellular organism have developed specializations, making them dependent on the remainder of the organism for survival. Stars in regions with a greater abundance of heavier elements that can form planets, in combination with a low rate of potentially habitat-damaging supernova events, are predicted to have a higher probability of hosting planets with complex life.

Photosynthesizing, porous edifices built of hydrothermally precipitated zinc sulfide as cradles of life on Earth", "Before Enzymes and Templates: Theory of Surface Metabolism", "On the origin of life in the zinc world. He also showed that RNA, the nucleic acid that many scientists believe served as the precursor to DNA-based life, is a particularly cheap building material.

Such phenomena are an experience of our daily life when we observe the growth of plants and animals. [215][216] It can occur as a result of an accident, medical conditions, biological interaction, malnutrition, poisoning, senescence, or suicide. Since living organisms probably first arose in an atmosphere lacking oxygen, anaerobic fermentation is the simplest and most primitive type of biological mechanism for obtaining energy from nutrient molecules. [278], The deep sea vent, or alkaline hydrothermal vent, theory posits that life may have begun at submarine hydrothermal vents,[279][280] Martin and Russell have suggested, that life evolved in structured iron monosulphide precipitates in a seepage site hydrothermal mound at a redox, pH, and temperature gradient between sulphide-rich hydrothermal fluid and iron(II)-containing waters of the Hadean ocean floor. [62] He argues that an ecosystemic definition of life is preferable to a strictly biochemical or physical one. Polyphosphates cause polymerization of amino acids into peptides. Jarzynski and Crooks showed that the entropy produced by a thermodynamic process, such as the cooling of a cup of coffee, corresponds to a simple ratio: the probability that the atoms will undergo that process divided by their probability of undergoing the reverse process (that is, spontaneously interacting in such a way that the coffee warms up). Origin of Life. Life forms live in every part of the Earth's biosphere, including soil, hot springs, inside rocks at least 19 km (12 mi) deep underground, the deepest parts of the ocean, and at least 64 km (40 mi) high in the atmosphere.

As Fermentation had around 1970 been elucidated, whereas the mechanism of oxidative phosphorylation had not and some controversies still existed, fermentation may have looked too complex for investigators of the origin of life at that time. These heavier elements allowed for the formation of new objects, including rocky planets and other bodies.[107]. Pyrimidine, like polycyclic aromatic hydrocarbons (PAHs), the most carbon-rich chemical found in the universe, may have been formed in red giants or in interstellar dust and gas clouds, according to the scientists. In 2004, a team detected traces of PAHs in a nebula. Extinction is the term describing the dying out of a group or taxon, usually a species. This formalism became known as Classical Irreversible Thermodynamics and Prigogine was awarded the Nobel Prize in Chemistry in 1977 "for his contributions to non-equilibrium thermodynamics, particularly the theory of dissipative structures". A Principle of Natural Self-Organization. Emily Singer contributed reporting. By Natalie Wolchover. The origin of life is a result of a supernatural event—that is, one irretrievably beyond the descriptive powers of physics, chemistry, and other science. [18][19] This conclusion is drawn from many independent lines of evidence, such as the observations that RNA is central to the translation process and that small RNAs can catalyze all of the chemical groups and information transfers required for life.

[94], The age of the Earth is about 4.54 billion years.

[130], One issue with the RNA world hypothesis is that synthesis of RNA from simple inorganic precursors is more difficult than for other organic molecules. Their microscopic compartments "provide a natural means of concentrating organic molecules," composed of iron-sulfur minerals such as mackinawite, endowed these mineral cells with the catalytic properties envisaged by Günter Wächtershäuser. [8][9] The classic 1952 Miller–Urey experiment and similar research demonstrated that most amino acids, the chemical constituents of the proteins used in all living organisms, can be synthesized from inorganic compounds under conditions intended to replicate those of the early Earth. Other locations within the Solar System that may host microbial life include the subsurface of Mars, the upper atmosphere of Venus,[207] and subsurface oceans on some of the moons of the giant planets. Part C: The Realistic Hypercycle", International Journal of Molecular Sciences, "The Emergence of Cells During the Origin of Life", "Coupled Phases and Combinatorial Selection in Fluctuating Hydrothermal Pools: A Scenario to Guide Experimental Approaches to the Origin of Cellular Life", "Histochemical localisation of RNA-like material in photochemically formed self-sustaining, abiogenic supramolecular assemblies 'Jeewanu, "Peptide glue may have held first protocell components together", "Electrostatic Localization of RNA to Protocell Membranes by Cationic Hydrophobic Peptides", "Letter no. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037, and weighs 50 billion tonnes. [234] Other scientific research has focused on two other potential reducing environments: outer space and deep-sea thermal vents.