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Topic: Chemical evolution


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In the News (Thu 23 Nov 17)

  
  Evolution - Wikipedia, the free encyclopedia
The belief in a telelogical evolution of this sort is known as orthogenesis, and is not supported by the scientific understanding of evolution.
The claim that evolution results in moral progress is not part of modern evolutionary theory – that claim is associated with Social Darwinism, which held that the subjugation of the poor, and of minority groups, was favored by evolution.
Here is the "tree of life" showing the evolution by reassortment of H5N1 that created the Z genotype in 2002 and here is evolution by antigenic drift that created dozens of highly pathogenic varieties of the Z genotype of avian flu virus H5N1, some of which are increasingly adopted to mammals.
en.wikipedia.org /wiki/Evolution   (9058 words)

  
 Chemical evolution 1 - Wikipedia, the free encyclopedia   (Site not responding. Last check: 2007-10-20)
Start the Chemical evolution 1 article or add a request for it.
Look for Chemical evolution 1 in Wiktionary, our sister dictionary project.
Look for Chemical evolution 1 in the Commons, our repository for free images, music, sound, and video.
www.sciencedaily.com /encyclopedia/chemical_evolution_1   (157 words)

  
 Bubble Genesis of Life
Speaking before a joint meeting of the International Society for the Study of the Origin of Life and the International Conference on the Origin of Life, Lerman described a geophysical framework for the chemical evolution that is thought to have set the stage for biogenesis.
From the spontaneous generation theory, in which life was thought to arise from nonliving matter, to the theory of panspermia, which maintained that life arrived in spores from outer space, the origins of life on earth has been a source of great debate.
When chemical evolution was first proposed, the assumption was that the process took place during the first one or even two billion years of earth's history.
www.lbl.gov /Science-Articles/Archive/bubble-genesis-of-life.html   (995 words)

  
 Evard, R. & Schrodetzki, D. --- Chemical Evolution
The chemical investigations that have developed from efforts to support the ideas set forth in Darwin's The Origin of Species (1) have given rise to a biochemical hypothesis which attempts to explain the origin of life as an evolutionary progression from simple prebiotic molecules to the complex and integrate biomolecules of today's living organisms.
Considering the thermodynamics of chemical evolution, especially the equilibrium concentrations of synthesized organic compounds, Hull demonstrated that the accumulation of amino acids on a primitive earth would result in a concentration hopelessly low and totally unsuitable as a starting material (18).
Chemical evolution; the amino acids released on hydrolysis of HCN oligomers.
www.grisda.org /origins/03009.htm   (7527 words)

  
 Chemical Evolution - Elemental Discoveries - 07/02   (Site not responding. Last check: 2007-10-20)
There is an element of truth in both perspectives where biological evolution proceeds through chemical changes - mutations, deletions and transpositions in the coils of nucleic acid - and living things respond blindly by altering their environment so that only those with chemistry suited to that environment survive intact to perpetuate the story.
The presence of a mere twenty or so chemical elements and how they interact in ways far more complex than the simple stoichiometric reactions of the average test-tube are available to life and have been since the time of its inception.
Chemical affinities, electronic configurations at the fundamental level forced some elements out of the emerging picture while others were placed in optimum states for further reactions including those involved in life.
www.sciencebase.com /jul02_iss.html   (1517 words)

  
 Chemical evolution models
Models of Galactic chemical evolution are nowadays able to reproduce the vast majority of the observed characteristics of our Galaxy.
In 2003, we have proceeded in the effort of accurately analysing the feedback between stellar and chemical evolution, the evolution of the abundance gradients and the impact of Galactic chemical evolution models on cosmology.
All the Galactic chemical evolution models able to reproduce the largest set of observational constraints have shown that the primordial abundance of
www.bo.astro.it /report03/node4.html   (342 words)

  
 TRANSPORT AND CHEMICAL EVOLUTION OVER THE PACIFIC (TRACE-P): A NASA/GTE AIRCRAFT MISSION
Different patterns of evolution are expected depending on the direction of outflow (tropics vs. high latitudes); the altitude (boundary layer vs. free troposphere); the presence of soil dust, soot, or other chemically active aerosols in the outflow; and the contributions from natural sources including lightning and stratospheric intrusions.
Fly in the same period as in PEM-West B (January 25-March 16, 1994) and concentrate on studies of the chemical evolution of pollution off the coast and to the south of China.
Chemical and aerosol forecasts using 3-D model simulations with forecast weather would be of considerable value for guiding the aircraft towards outflow regions and for planning chemical aging flights.
www-gte.larc.nasa.gov /trace/tracep.html   (5213 words)

  
 sciforums.com - Chemical Evolution in the Early Ocean
Continuing with the subject of early evolution, light absorbing porphyrin rings became encased in molecules that are hydrophobic on one end and hydrophilic on the other.
Continuing on the subject of chemical evolution in the early ocean: When the ocean was at the stage of having a popuation of porphyrin rings, it was populated not by one species of porphyrin, but many.
Billions of trillions of chemicals that sparked billions of times over where a pool of DNA type cjemicals were formed and, to make a story short, we look like mpmkeys, not from a common ancestral train, but from a long parallel but incompatible for mixing chain.
www.sciforums.com /showthread.php?t=42725   (2474 words)

  
 Carnegie Observatories Research: Andrew McWilliam   (Site not responding. Last check: 2007-10-20)
Andrew McWilliam studies red giant stars because they provide a useful probe to study chemical evolution in the local universe: they are bright enough to be studied at great distances, and they arise from young and old populations.
Additionally, since the chemical composition of their surface has remained largely unchanged, they form a fossil record of chemical evolution in the universe.
McWilliam, A. Abundance ratios and galactic chemical evolution, ARAA 35, 503.
www.ociw.edu /research/mcwilliam.html   (553 words)

  
 Life in the universe takes orders from space
According to Pizzarello, who studies meteorites from the collection at ASU (which has the largest university-owned collection in the world) the meteorites are the only evidence of chemical evolution scientists have in hand today.
The paper addresses what has been a basic difficulty in relating the chemical evolution represented by meteorites and the origin of terrestrial life on Earth.
According to Pizzarello, this problem is that chemical evolution - what we see in meteorites - is characterized by randomness, while terrestrial life relies on specificity and selection.
www.eurekalert.org /pub_releases/2004-02/asu-lit021804.php   (782 words)

  
 The Myth of Chemical Evolution [Free Republic]
Chemically they are NH2CH(R)COOH, where R is H in the simplest case, glycine, but can also be a variety of organic groups such as CH3 in alanine.
Certainly the tiniest of pathogens, viruses and prions, inhabit a very gray area in which it is debatable whether they are alive or not, yet even if one dismisses them as simply clever chemicals, one cannot deny their close similarity in behavior to aknowledged life forms of only slightly larger size.
In the limited scale uf human experience, it may seem improbable that these chemicals would chance to form somethign that is alive, until you consider that oceans full of such amino acids provide quintillions of trial and error combinations every single second.
www.freerepublic.com /forum/a3925c4466186.htm   (7603 words)

  
 Chemical Evolution (Stephen Mason) - book review
Chemical Evolution has made me reconsider this, although in a curious way it also confirms my prejudices.
The chapter on genealogy and reproduction is fairly standard stuff and the chapter on the origins of life could have been extended, but the overall presentation is good.
All round Chemical Evolution is a fascinating book, which goes into much more detail than is found in popular accounts while maintaining an approachable presentation.
www.dannyreviews.com /h/Chemical_Evolution.html   (435 words)

  
 Creation and Evolution Controversy
Chance is frequently seen as the bogey man in evolution, but the scripture indicates otherwise.
From a scientific point of view we have to distinguish between evolution as it can be scientifically observed such as bacteria mutations etc and the processes that led to the origin of man which cannot be observed directly and are therefore subject to speculation.
Ones belief in evolution or creation is determined by ones world view and not by the evidence which is not so compelling as to force one to believe in evolution.
ourworld.compuserve.com /homepages/rossuk/creation.htm   (898 words)

  
 Science Shorts - Articles and Explorations - Chemical Evolution
One of the explanations put forward to explain the origin of life is the Chemical Evolution theory.
The theory of chemical evolution involves a list of unlikely conditions, including that somehow the special coded order in DNA had to happen.
There may be some surprises round the corner, but at present chemical evolution can only be defended as a philosophical viewpoint, and not a conclusion of science.
www.scienceshorts.com /articles/ce.htm   (1125 words)

  
 The National Academies
While the mechanisms of evolution are still under investigation, scientists universally accept that the cosmos, our planet, and life evolved and continue to evolve.
The study of planetary biology and chemical evolution draws together experts in astronomy, paleobiology, biochemistry, and space science who work together to understand the evolution of living systems.
The volume examines early cellular evolution, explores changes in the tempo of evolution between the Precambrian and Phanerozoic periods, and reconstructs the Cambrian evolutionary burst.
www.nationalacademies.org /evolution   (1174 words)

  
 Cosmic Evolution - Epoch 5 - Chemical Evolution
Having encountered many of the astronomical and physical (or “astrophysical”) concepts needed to appreciate the origin and evolution of matter, we now consider some of the biological and chemical (or “biochemical”) ideas central to the origin and evolution of life.
In this, the fifth, CHEMICAL EPOCH, we explore the ways and means that the building blocks of life eventually became life.
Both of these choices, sketched diagrammatically in Figure 5.1, are consistent with the basic ideas of cosmic evolution, yet the chances for life elsewhere in the Universe depend critically on which of these two cases pertain.
www.tufts.edu /as/wright_center/cosmic_evolution/docs/text/text_chem_1.html   (1899 words)

  
 Space Studies Board
As is apparent from the preceding chapters, research in chemical evolution and planetary biology extends over many "classical" scientific disciplines and brings together investigators from seemingly disparate areas.
One aspect of this issue is that investigators interested in chemical evolution and planetary biology are often precluded from making serious proposals for space-borne experiments because specific hardware or even concepts for flight instrumentation are not available for evaluation at the time of payload selection.
Because of the essential role of space technology in many aspects of research in chemical evolution and planetary biology, almost all of the support for this field, and for integration of its various elements, is now borne by a single federal agency, NASA, through its grants and in-house activities.
www7.nationalacademies.org /ssb/lifeoriginsch8.html   (953 words)

  
 Major galactic mystery solved by CU astronomers
Researchers at the University of Colorado at Boulder have solved a major galactic mystery that may help astronomers in their quest to develop a detailed picture of the chemical evolution of the Milky Way galaxy.
It could indicate a much smaller amount of chemical evolution in our galaxy, a much higher value for the assumed infall of near primordial gas to the Milky Way galaxy, some as yet unknown process or a combination of these effects.
"Astronomers are developing a detailed picture of galactic chemical evolution, but the abundance of deuterium, one of the key tracers of this evolution, has been highly uncertain until now," Linsky said.
www.eurekalert.org /pub_releases/2004-06/uoca-mgm060104.php   (739 words)

  
 Open Directory - Science: Biology: Evolution   (Site not responding. Last check: 2007-10-20)
Evolution by Natural Selection - An introduction to how the appearance of design in the living world arose from a mindless process.
Evolution of Evolvability - This paper shows how evolution tunes the content and frequency of genetic variation to enhance its evolvability, organising genetic systems into hierarchies.
Evolution's Arrow - Web version of a book written by John Stewart about the direction of evolution and the future of humanity.
www.dmoz.org /Science/Biology/Evolution   (725 words)

  
 Chemical evolution   (Site not responding. Last check: 2007-10-20)
A chemical is a either a chemical element or a material with a defined composition of such elements: a chemical compound.
Chemicals is the industry or trade of producing or manipulating such chemicals.
The patrons gather to discuss evolutionary theory, critique the claims of the antievolution movement, defend the integrity of both science and science education, and share good conversation.
www.serebella.com /encyclopedia/article-Chemical_evolution.html   (525 words)

  
 Chemical evolution bibliography
Calvin, M., 1969, Chemical Evolution: Oxford, Oxford University Press, 278 p.
Dickerson, R. E., 1978, Chemical evolution and the origin of life: Scientific American, v.
Gish, D. T., 1976, Origin of life: critique of early stage chemical evolution theories: ICR Impact Series, v.
www.talkorigins.org /origins/biblio/chemical_evolution.html   (114 words)

  
 Chemical Evolution - Free Christian Internet Articles   (Site not responding. Last check: 2007-10-20)
To prove Chemical Evolution was possible, the duo combined the gases they believed present on primitive Earth (hydrogen, methane, ammonia, and water vapor) with liquid water in a sterile glass container.
Like it or not, Evolution Experts are just a bug's hair away from concluding that life originated via a purposeful implantation of tiny Alien organisms by advanced Aliens who began evolving perhaps a billion years prior to homo sapiens.
Evolution Experts may not know it yet, but they are dangerously close to endorsing the concept of creators.
www.volunteersforchrist.com /articles/EvolutionChemical.htm   (2197 words)

  
 The Hindu : Major galactic chemical mystery solved
It could indicate a smaller amount of chemical evolution in our galaxy, a higher value for the assumed in-fall of near primordial gas to the Milky Way galaxy, some as yet unknown process or a combination of these effects.
The ability to measure it today will allow astronomers to have a better understanding of the chemical evolution of the Milky Way and other galaxies since most of the deuterium present in the universe was created at the time of the Big Bang.
It is believed that over time the abundance of deuterium in the universe has decreased as it is converted to helium and other heavier elements by nuclear reactions in the hot interiors of stars.
www.hindu.com /seta/2004/06/17/stories/2004061700271500.htm   (515 words)

  
 Research
  We recently applied a chemical evolution model to damped Lyman alpha systems and showed that it is plausible to account for the recent measurements of a variation in the fine-structure constant.
  Besides Galactic chemical evolution and nucleosynthesis, I am interested in models of stellar evolution and population synthesis, chaotic dynamics and statistical analysis, effects of nuclear reaction rate uncertainties on nucleosynthesis, gravitational microlensing, formation of globular cluster and its metal dispersions, and hydrodynamical models.
Some of the general questions involving chemical evolution, dynamical evolution, and population synthesis for which I hope to contribute to are:
www.nd.edu /~tashenfe/research.html   (672 words)

  
 Chemical Evolution New, Used Books, Cheap Prices, ISBN 0792341112   (Site not responding. Last check: 2007-10-20)
Chemical Evolution of the Galaxy (By Francesca Matteucci)
Nucleosynthesis and Chemical Evolution of Galaxies (By Bernard E.J. Pagel)
Chemical Evolution of the Early Precambrian (By Cyril Ponnamperuma (Editor))
www.bookfinder4u.com /detail/0792341112.html   (387 words)

  
 Chemical Evolution of Galaxies
This group is investigating the time evolution of chemical abundances in the universe, including QSO (quasi-stellar objects) absorption and spectra.
We are also carrying out theoretical studies of the chemical evolution of galaxies, particularly the effects of gas flows, and determination of chemical abundances from spectra of HII regions and stars.
We have recently been investigating the evolution of the dust cycle in galaxies, particularly in the origin of dust.
www.astro.cf.ac.uk /groups/chemevol   (229 words)

  
 Matteucci, Francesca (dept. Of Astronomy) (ed.) - The Chemical Evolution Of The Galaxy (isbn 0792365526) - new and used ...
Alibris - The Chemical Evolution of the Galaxy
Matteucci, Francesca - The Chemical Evolution of the Galaxy
Matteucci, Francesca - CHEMICAL EVOLUTION OF THE GALA
www.isbn.pl /I-0792365526/The-Chemical-Evolution-of-the-Galaxy-Astrophysics-Space-Science-Library.html   (722 words)

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