Theory of Intelligent Design, the best explanation of Origins

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Theory of Intelligent Design, the best explanation of Origins » Origin of life » Current origin of life proposals

Current origin of life proposals

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1 Current origin of life proposals on Sun Mar 26, 2017 6:54 am


Current origin of life proposals

Regularly science journals and papers come up with new OOL ( origin of life ) scenarios. Here I will analyze them.

Serpentinization is a process whereby rock (usually ultramafic) is changed, with the addition of water into the crystal structure of the minerals found in the rock.

Transition metal sulfides
From the biological side, many phylogenomic studies conclude that clades exclusive to hydrothermal vents are the deepest branches in the tree of life. Further, most metabolic enzymes that catalyze anaerobic reactions with small gas molecules depend on transition metal sulfide clusters that have been noted to resemble minerals common to vents

The emergence of life from iron monosulphide bubbles at a submarine hydrothermal redox and pH front

Life on Earth may have begun as dividing droplets
In a primordial soup on ancient Earth, droplets of chemicals may have paved the way for the first cells. Shape-shifting droplets split, grow and split again in new computer simulations. The result indicates that simple chemical blobs can exhibit replication, one of the most basic properties of life, physicist Rabea Seyboldt of the Max Planck Institute for the Physics of Complex Systems in Dresden, Germany, reported March 16 at a meeting of the American Physical Society.

Universal ancestor of all life on Earth was only half alive
One characteristic of almost all living cells is that they pump ions across a membrane to generate an electrochemical gradient, then use that gradient to make the energy-rich molecule ATP. Martin’s results suggest LUCA could not generate such a gradient but could harness an existing one to make ATP.

That fits in beautifully with the idea that the first life got its energy from the natural gradient between vent water and seawater, and so was bound to these vents. Only later did the ability to generate gradients evolve, allowing life to break away from the vents on at least two occasions – one giving rise to the first archaea, the other to bacteria.

The Emergence of Life as a First-Order Phase Transition
March 1, 2017
Here we present a model for the emergence of life in which replicators are explicitly coupled to their environment through the recycling of a finite supply of resources. The model exhibits a dynamic, first-order phase transition from nonlife to life, where the life phase is distinguished by selection on replicators. We show that environmental coupling plays an important role in the dynamics of the transition. The transition corresponds to a redistribution of matter in replicators and their environment, driven by selection on replicators, exhibiting an explosive growth in diversity as replicators are selected.

Molecules assemble in water, hint at origins of life
February 20, 2013
Researchers are exploring an alternate theory for the origin of RNA: they think the RNA bases may have evolved from a pair of molecules distinct from the bases we have today. This theory looks increasingly attractive, as researchers were able to achieve efficient, highly ordered self-assembly in water with small molecules that are similar to the bases of RNA.

Meteorite Chemicals May Have Started Life on Earth—and Space
April 16, 2015
The molecules that kick-started life on primordial Earth could have been made in space and delivered by meteorites, according to researchers in Italy. The group synthesised sugars, amino acids and nucleobases with nothing more than formamide, meteorite material and the power of a simulated solar wind, replicating a process they believe cooked up a prebiotic soup long before life existed on Earth.

NASA Has Found The Ingredients For Life On Saturn’s Moon Enceladus
(Reuters) – Ice plumes shooting into space from Saturn’s ocean-bearing moon Enceladus contain hydrogen from hydrothermal vents, an environment that some scientists believe led to the rise of life on Earth, research published on Thursday showed.The discovery makes Enceladus the only place beyond Earth where scientists have found direct evidence of a possible energy source for life, according to the findings in the journal Science.Similar conditions, in which hot rocks meet ocean water, may have been the cradle for the appearance of microbial life on Earth more than 4 billion years ago.

Thermodynamic origin of life
9 September 2010
Understanding the thermodynamic function of life may shed light on its origin. Life, as are all irreversible processes, is contingent on entropy production. Entropy production is a measure of the rate of the tendency of Nature to explore available microstates. The most important irreversible process generating entropy in the biosphere, and thus facilitating this exploration, is the absorption and transformation of sunlight into heat. Here we hypothesize that life began, and persists today, as a catalyst for the absorption and dissipation of sunlight at the surface of shallow seas. The resulting heat is then efficiently harvested by other irreversible processes such as the water cycle, hurricanes, and ocean and wind currents. RNA and DNA are the most efficient of all known molecules for absorbing the intense ultraviolet light that could have penetrated the dense early atmosphere, and are remarkably rapid in transforming this light into heat in the presence of liquid water. From this perspective, the origin and evolution of life, inseparable from water and the water cycle, can be understood as resulting from the natural thermodynamic imperative of increasing the entropy production of the Earth in its interaction with its solar environment. A mechanism is proposed for the reproduction of RNA and DNA without the need for enzymes, promoted instead through UV light dissipation and the ambient conditions of prebiotic Earth.

The Emergence of Cells During the Origin of Life
Science  08 Dec 2006:
simple physicochemical properties of elementary protocells can give rise to essential cellular behaviors, including primitive forms of Darwinian competition and energy storage. Such preexisting, cooperative interactions between the membrane and encapsulated contents could greatly simplify the transition from replicating molecules to true cells. They also suggest intriguing possibilities for further investigation. For example, a corollary of vesicle competition is that a charged genetic polymer, such as nucleic acid, would be much more effective at driving membrane uptake than an electrically neutral polymer, because most of the osmotic pressure is due to counterions associated with the charged polymer. Could this influence the natural selection of the genetic material itself? Furthermore, competition for membrane molecules would favor stabilized membranes, suggesting a selective advantage for the evolution of cross-linked fatty acids (e.g., di- and triglycerides) and even the phospholipids of today. Greater membrane stability leads to decreased dynamics, however, and the evolutionary solutions to this problem (e.g., permeases, synthetic enzymes) could cause a “snowball” effect on the complexity of early life (16). Exploration of these minimal systems promises to lead to more exciting insights into the origins of biological complexity.

Chemists may be zeroing in on chemical reactions that sparked the first life
By Robert F. ServiceMay. 19, 2017 , 6:00 AM
DNA is better known, but many researchers today believe that life on Earth got started with its cousin RNA, because that nucleic acid can act as both a repository of genetic information and a catalyst to speed up biochemical reactions. But those favoring this “RNA world” hypothesis have struggled for decades to explain how the molecule’s four building blocks could have arisen from the simpler compounds present during our planet’s early days. Now, chemists have identified simple reactions that, using the raw materials on early Earth, can synthesize close cousins of all four building blocks. The resemblance isn’t perfect, but it suggests scientists may be closing in on a plausible scenario for how life on Earth began.

RNA’s four building blocks are called nucleotides. Each is composed of ribose, a ring-shaped sugar molecule, connected to one of four different ring-shaped “bases,” adenine (A), guanine (G), cytosine (C), and uracil (U). C and U are structurally similar to each other and collectively known as pyrimidines, whereas A and G resemble each other and are known as purines. In 2009, researchers led by Matthew Powner and John Sutherland at the Medical Research Council in Cambridge, U.K., came up with the first plausible chemical reactions that could have synthesized pyrimidines on early Earth. But very different reactions, in different conditions, seemed necessary to make purines. That begged the question of how all four nucleotides could have wound up in the same place to give rise to the first “living” RNA molecules.

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