Thank God none of this crap is true. You Fail again Dave.
Origin of Life: the Early Atmosphere
Our current atmosphere consists primarily of oxygen (21%) and nitrogen (78%) and is called oxidizing because of chemical reactions produced by oxygen. For example, iron is oxidized to form iron oxide or rust.
The presence of oxygen in a hypothetical primordial atmosphere poses a difficult problem for notions of self-assembling molecules. If oxygen is present, there would be no amino acids, sugars, purines, etc. Amino acids and sugars react with oxygen to form carbon dioxide (CO2) and water.
Because it is impossible for life to evolve with oxygen, evolutionists theorize an early atmosphere without oxygen. This departs from the usual evolutionary theorizing where a uniformistic view is held (i.e. where processes remain constant over vast stretches of time). In this case the present is NOT the key to the past.
Instead, they propose a "reducing" (called thus because of the chemical reactions) atmosphere which contains free hydrogen. Originally, they postulated an atmosphere consisting of carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), ammonia (NH3), free hydrogen and water vapor. Newer schemes exclude ammonia and methane.
There is a problem if you consider the ozone (O3) layer which protects the earth from ultraviolet rays. Without this layer, organic molecules would be broken down and life would soon be eliminated. But if you have oxygen, it prevents life from starting. A "catch-22" situation (Denton 1985, 261-262):
Atmosphere with oxygen => No amino acids => No life possible!
Atmosphere without oxygen => No ozone => No life possible!
In must be noted at this point that the existence of a reducing atmosphere is theoretical and does not rely on physical evidence. To the contrary, there are geological evidences for the existence of an oxidizing atmosphere as far back as can be determined. Among these are: the precipitation of limestone (calcium carbonate) in great quantities, the oxidation of ferrous iron in early rocks (Gish 1972, 8 ) and the distribution of minerals in early sedimentary rocks (Gish 1984T).
This contains so much errors I don't really know where do I start...
Well, let's start with the idea that without ozone there is no life possible because the lack of ozone would have broken down organic molecules. It's actually the exact opposite as studies have pointed out. UV light helped the generation of the building blocks of life:
A key event in the origin of life on this planet has been formation of self-replicating RNA-type molecules, which were complex enough to undergo a Darwinian-type evolution (origin of the "RNA world"). However, so far there has been no explanation of how the first RNA-like biopolymers could originate and survive on the primordial Earth.
As condensation of sugar phosphates and nitrogenous bases is thermodynamically unfavorable, these compounds, if ever formed, should have undergone rapid hydrolysis. Thus, formation of oligonucleotide-like structures could have happened only if and when these structures had some selective advantage over simpler compounds. It is well known that nitrogenous bases are powerful quenchers of UV quanta and effectively protect the pentose-phosphate backbones of RNA and DNA from UV cleavage. To check if such a protection could play a role in abiogenic evolution on the primordial Earth (in the absence of the UV-protecting ozone layer), we simulated, by using Monte Carlo approach, the formation of the first oligonucleotides under continuous UV illumination. The simulations confirmed that UV irradiation could have worked as a selective factor leading to a relative enrichment of the system in longer sugar-phosphate polymers carrying nitrogenous bases as UV-protectors. Partial funneling of the UV energy into the condensation reactions could provide a further boost for the oligomerization.
These results suggest that accumulation of the first polynucleotides could be explained by their abiogenic selection as the most UV-resistant biopolymers.
Shining Light on Life's Origin
By: Leslie Mullen
A 3D structure of RNA.
Doctors urge us to wear sunscreen and try to stay out of the sun. The sun's ultraviolet (UV) rays damage our skin and are a leading cause of skin cancer.
UV light has been just as shunned in theories on the origin of life. The early Earth did not have an ozone layer, so UV radiation would have been 100 times today's levels. It is generally believed that the delicate molecules of life's beginning would have deteriorated under this light intensity.
Many scientists say that life's origin most likely occurred in places sheltered from UV light, such as the hydrothermal vents deep under the sea. But a new study, published in BioMed Central journal Evolutionary Biology, says rather than hinder the origin of life, UV rays helped and may even have been a necessary ingredient for life's formation.
Armen Mulkidjanian, with his colleagues from Osnabrück University, Germany and the National Institutes of Health, USA, used computer models to test RNA's ability to form from sugar, phosphates, and nitrogenous bases in the presence of high levels of UV light.
While the researchers acknowledge that UV can be damaging to RNA, they discovered that some parts of the molecule act as a protective shield for other parts. The nitrogenous bases absorb and disperse UV radiation, protecting the RNA's pentose-phosphate backbone.
This 3D hammerhead ribozyme structure (in red, green, and purple) is shown bound to an all-DNA substrate inhibitor (in blue).
Credit: Pley, Flaherty and McKay/Nature
"Apparently, the backbones of DNA and RNA can be rescued by the partial "victimization" of the nitrogenous bases," the scientists write. "One can assume that these bases had been selected to perform the UV-protecting function before they became involved in the maintenance and transfer of genetic information."
Since double strands provide more UV protection to the RNA backbone than single-strands, the scientists suggest that base-pairing may have originated as a trait to provide greater UV protection. Only later did these bases evolve to perform their current functions.
In the computer simulation, the stability of RNA under UV radiation gave the molecules a selective advantage, allowing the number of RNA molecules to increase under natural selection.
"In the UV-illuminated primordial world, the probability of a UV-breakage was more than real for any compound," the scientists write. "Those that succeeded to bind a UV-quencher got a selective advantage."
RNA is thought to be one of the most important molecules in the origin of life on Earth. The discovery of ribozymes led to the "RNA world" theory, in which RNA both stored genetic information and catalyzed its own replication. This presumably led to the contemporary DNA and protein world, where DNA acts as genetic storage and proteins are needed to catalyze replication.
"I believe that UV radiation has often gotten a "bad rap" in the origins community, which has led many researchers to dismiss its importance," says William Hagan, an associate scientist with the New York Center for Studies on the Origin of Life.
Hagan says we should recognize ultraviolet light as not only an incinerator of the organic precursors of life, but also as a fuel for creating those same materials. UV's simultaneous destructive and creative properties seem to create a paradox, but Hagan says the solution is to identify protected environments on the early Earth where the higher-energy "bad" rays were dispersed through seawater or minerals.
"I just don't think that we can ignore the tremendous power of solar energy as the most abundant fuel on the early Earth." -William Hagan
Charles Darwin thought that life could have originated "in some warm little pond, with all sorts of ammonia and phosphoric salts, light, electricity, etc. present." Researchers have reflected upon Darwin's sunlit shallow pool ever since. John Desmond Bernal, for instance, said that life could have begun in tidal regions, where molecules faced alternating wet and dry periods. The wet period would dissolve chemicals and allow them to react with each other, while the dry periods would allow the chemicals to condense, spurring further reactions.
Yet the danger of UV damage prompted other scientists to suggest that a protective water layer would be necessary. Such an environment, however, would eliminate the possibility of the condensation reactions. But if Mulkidjanian's study is correct, then the UV exposure of tidal regions would not prevent the origin of an RNA world.
Hagan says that he, too, favors surface environments like the tidal lagoons for the origin of life. He thinks that while hydrothermal vents may have contributed to the concentration of organic chemicals, the sun provided a more widespread and intense energy source.
"I just don't think that we can ignore the tremendous power of solar energy as the most abundant fuel on the early Earth," Says Hagan.
Mulkidjanian and his colleagues suggest that their hypothesis could be tested further. A reactor system could be set up to enable nucleotides to form from simpler molecules under conditions of UV-irradiation, with aluminosilicate clays added to catalyze the nucleotide formation.
"If confirmed by experiment, this would provide an exciting new role for UV light in the selective formation of biopolymers," says Hagan.
Here's another experiment on the generation of life, that included radiation to create the first building blocks of life:http://www.wired.com/wiredscience/2009/05/ribonucleotides/
Life’s First Spark Re-Created in the Laboratory
A fundamental but elusive step in the early evolution of life on Earth has been replicated in a laboratory.
Researchers synthesized the basic ingredients of RNA, a molecule from which the simplest self-replicating structures are made. Until now, they couldn’t explain how these ingredients might have formed.
“It’s like molecular choreography, where the molecules choreograph their own behavior,” said organic chemist John Sutherland of the University of Manchester, co-author of a study in Nature Wednesday.
RNA is now found in living cells, where it carries information between genes and protein-manufacturing cellular components. Scientists think RNA existed early in Earth’s history, providing a necessary intermediate platform between pre-biotic chemicals and DNA, its double-stranded, more-stable descendant.
However, though researchers have been able to show how RNA’s component molecules, called ribonucleotides, could assemble into RNA, their many attempts to synthesize these ribonucleotides have failed. No matter how they combined the ingredients — a sugar, a phosphate, and one of four different nitrogenous molecules, or nucleobases — ribonucleotides just wouldn’t form.
Sutherland’s team took a different approach in what Harvard molecular biologist Jack Szostak called a “synthetic tour de force” in an accompanying commentary in Nature.
“By changing the way we mix the ingredients together, we managed to make ribonucleotides,” said Sutherland. “The chemistry works very effectively from simple precursors, and the conditions required are not distinct from what one might imagine took place on the early Earth.”
Like other would-be nucleotide synthesizers, Sutherland’s team included phosphate in their mix, but rather than adding it to sugars and nucleobases, they started with an array of even simpler molecules that were probably also in Earth’s primordial ooze.
They mixed the molecules in water, heated the solution, then allowed it to evaporate, leaving behind a residue of hybrid, half-sugar, half-nucleobase molecules. To this residue they again added water, heated it, allowed it evaporate, and then irradiated it.
At each stage of the cycle, the resulting molecules were more complex. At the final stage, Sutherland’s team added phosphate. “Remarkably, it transformed into the ribonucleotide!” said Sutherland.
According to Sutherland, these laboratory conditions resembled those of the life-originating “warm little pond” hypothesized by Charles Darwin if the pond “evaporated, got heated, and then it rained and the sun shone.”
Such conditions are plausible, and Szostak imagined the ongoing cycle of evaporation, heating and condensation providing “a kind of organic snow which could accumulate as a reservoir of material ready for the next step in RNA synthesis.”
Intriguingly, the precursor molecules used by Sutherland’s team have been identified in interstellar dust clouds and on meteorites.
“Ribonucleotides are simply an expression of the fundamental principles of organic chemistry,” said Sutherland. “They’re doing it unwittingly. The instructions for them to do it are inherent in the structure of the precursor materials. And if they can self-assemble so easily, perhaps they shouldn’t be viewed as complicated.”