Origin of life Origin of life Abiogenesis ( Greek a-bio-genesis, "non biological origins") is, in its most general sense, the generation of life from non-living matter. Today the term is primarily used to refer to theories about the chemical origin of life, such as from a primordial soup. Earlier notions of abiogenesis, now more commonly known as spontaneous generation, held that living organisms are generated by decaying organic substances, e.g. that mice spontaneously appear in stored grain or maggots spontaneously appear in meat. (That idea, which has long been known to be incorrect, will be called "Aristotelian abiogenesis" in this article.) ...more on Wikipedia about "Abiogenesis"
Akilia island is in West Greenland, about 22 kilometers south of Nuuk (Godthab), at . Akilia is the location of a controversial rock outcropping that some geologists believe is the oldest known sedimentary rocks, and perhaps the oldest evidence of life on Earth or anywhere else. ==Geology== The formation in question, at the southern tip of the island has been dated as no younger than 3.85 Ga ( Hadean), based on the age of an igneous band that cuts the rock. As a result, they may be older. It has been claimed that the Akilia sediments include banded iron beds, thought to be the result of oxygen released by photosynthetic organisms combining with dissolved iron to form insoluble iron oxides. Carbon deposits in the rock show low levels of Carbon-13. Kerogen deposits (derived from organic matter) are isotopically light (i.e. more negative δ13C values) which is indicative of photosynthesis (see Schidlowski, 1988). However, this interpretation is under doubt as the Akilia rocks have undergone high-temperature metamorphosis which is known to be fractionating itself (Gilmour & Wright, 1997). There is also a lack of corroborating sulfur isotope fractionation (Nisbet, 2000). Both the sedimentary origin and the carbon content of the rocks have been questioned (Lepland et al, 2005). If the Akilia rocks do show evidence of life at 3.85Ga, the time available for life to organize itself on Earth would be tightly limited, since other evidence suggests the Earth would not be hospitable to life before 3.9Ga. Research is continuing. ==See also== * Origin of life * Panspermia ==Papers== *Gilmour I, Wright I, Wright J, Origins of Earth and Life, The Open University, 1997, ISBN 0749281820 ...more on Wikipedia about "Akilia island"
An aromatic hydrocarbon (abbreviated as AH), or arene is a hydrocarbon, the molecular structure of which incorporates one or more planar sets of six carbon atoms that are connected by delocalised electrons numbering the same as if they consisted of alternating single and double covalent bonds. ...more on Wikipedia about "Aromatic hydrocarbon"
An autocatalytic set is a collection of entities, each of which is able to catalyze the creation of others within the set, such that as a whole, the set is able to catalyze its own replication. In this way the set as a whole is said to be autocatalytic. Autocatalytic sets were originally and most concretely defined in terms of entities which are replicating molecules, but have more recently been metaphorically extended to the study of systems in sociology and economics. ...more on Wikipedia about "Autocatalytic set"
Biogenesis has two meanings. On one hand it is the process of lifeforms producing other lifeforms, e.g. a spider lays eggs, which form into spiders. A second meaning was given by the French Jesuit priest, scientist and philosopher Pierre Teilhard de Chardin to mean the origin of life itself. ...more on Wikipedia about "Biogenesis"
Biopoiesis or biopoesis is the process of living matter evolving from self-replicating but nonliving molecules. This theory describes the origin of life on Earth, the earliest evidence of which points to life arising 3.87 billion years ago. ...more on Wikipedia about "Biopoiesis"
Chemical evolution has two meanings and uses. The first refers to the theories of evolution of the chemical elements in the universe following the Big Bang and through nucleosynthesis in stars and supernovas. ...more on Wikipedia about "Chemical evolution"
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The iron-sulfur world theory is a hypothesis for the origin of life advanced by Günter Wächtershäuser involving forms of iron and sulfur. Wächtershäuser claims that an early form of metabolism predated genetics. Metabolism here means a cycle of chemical reactions that produce energy in a form that can be harnessed by other processes. The idea is that once a primitive metabolic cycle was established, it began to produce ever more complex compounds. ...more on Wikipedia about "Iron-sulfur world theory"
Description: Henry Gray's Anatomy of the Human Body, commonly known as Gray's Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. The book was first published under the title Gray's Anatomy: Descriptive and Surgical in Great Britain in 1858, and the following year in the United States. The book's British author died after the publication of the 1860 second edition, at the age of 34, but his much-praised book was continued by others and on November 24, 2004, the 39th British edition was released. ...more on Wikipedia about "List of publications in biology"
The Miller-Urey experiment (or Urey-Miller experiment) was an experiment that simulated hypothetical conditions present on the early Earth and tested for the occurrence of chemical evolution (the Oparin and Haldane hypothesis stated that conditions on the primitive Earth favored chemical reactions that synthesized organic compounds from inorganic precursors; the Miller-Urey tested this hypothesis). The experiment is considered to be the classic experiment on the origin of life. It was conducted in 1953 by Stanley L. Miller and Harold C. Urey at the University of Chicago. ...more on Wikipedia about "Miller-Urey experiment"
The Murchison meteorite is named after Murchison, Victoria in Australia. Fragments of the meteorite fell near the village on 28 September 1969. The meteorite, a type II carbonaceous chondrite, was found to contain common amino acids such as glycine, alanine and glutamic acid but also unusual ones like isovaline and pseudoleucine [1]. The initial report stated that the amino acids were racemic supporting a theory that the source is extraterrestrial. A complex mixture of alkanes was isolated as well which was similar to that found in the Miller-Urey experiment. Serine and threonine are usually considered earthly contaminants and these compounds were conspicuously absent in the samples. ...more on Wikipedia about "Murchison meteorite"
Research into the origin of life is a limited field of research despite its profound impact on biology and human understanding of the natural world. Progress in this field is generally slow and sporadic, though it still draws the attention of many due to the gravity of the question being investigated. ...more on Wikipedia about "Origin of life"
Panspermia is the hypothesis that the seeds of life are ubiquitous in the universe, that they may have delivered life to Earth, and that they may deliver or have delivered life to other habitable bodies; also the process of such delivery. ...more on Wikipedia about "Panspermia"
The primordial sea, or primordial ocean, is a term applied collectively to the oceans of the earth at a time early in its history. The term generally implies either the time before or during the development of multi-cellular life forms (i.e., during the Precambrian), or alternatively before the development of the first land-based life forms (i.e. during the early Paleozoic). ...more on Wikipedia about "Primordial sea"
The RNA world hypothesis proposes that RNA was actually the first life-form on earth, later developing a cell membrane around it and becoming the first prokaryotic cell. ...more on Wikipedia about "RNA world hypothesis"
The Urantia Book (TUB or UB), is a spiritual or religious tome that covers an in-depth portrayal of God, the universe, the planet, evolution, history, philosophy, religion, and destiny. Sometimes it is referred to as "The Urantia Papers" (TUP), or " The Fifth Epochal Revelation" (FER). ...more on Wikipedia about "The Urantia Book"
Thioesters are compounds resulting from the bonding of sulfur with an acyl group (an alkyl group attached to a carbon-oxygen double bond), with the general formula R-S-CO-R'. ...more on Wikipedia about "Thioester"
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