THE POSTS MOSTLY BY GEOGRAPHICAL DISTRIBUTION

THE POSTS MOSTLY BY GEOGRAPHICAL DISTRIBUTION

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Boston artist Steve Mills - realistic painting

Thursday, June 17, 2010

Did DNA-Based Life Begin in Nebula & Interstellar Clouds?


Did DNA-Based Life Begin in Nebula & Interstellar Clouds?



Stellar debris, nebulae such as the Bubble (image above) and Orion Nebula, and interstellar clouds contain hydrogen, oxygen, carbon, sulfur, nitrogen, phosphorus, water vapour, methanol, ethanol, cyanide, ammonia, formaldehyde, and complex organic molecules. A spectral line survey of Orion nebular clouds has identified 40 different molecular species, including several organic compounds such as methyl cyanide, methanol, and dimethyl ether. An examination of a nebular cloud within 3 astronomical units of AA Tauri revealed the presence of an abundance of simple organic molecules (HCN, C2H2, and CO2), water vapor, and OH. Water was particularly abundant throughout the inner disk which is a strong indication of active organic chemistry.
There is an abundance of organic molecules, water, and polycyclic aromatic hydrocarbons within interstellar clouds, which indicates either the presence of life, and serve as important ingredients for creating life.
Based on results from the European Space Agency's infrared space observatory, the Spitzer and other space telescopes, the chemical synthesis of complex organic molecules occurs rapidly in different stellar environments. A comparative analysis of infrared spectra, indicates that small organic molecules can evolve into complex organic molecules. This includes inducing chiral asymmetry in interstellar organic molecules leading, possibly to an excess of L-amino acids. Amino acids appear to be generated and synthesized in these stellar environments. Sixty amino acids have been detected, including eight of the twenty amino acids necessary for life. In fact, the UV irradiation of interstellar ice analogs is known to lead to the formation and synthesis of organic compounds (Troop and Baily 2009) such as amino acids and what may be nucleobases. 
A wide-field and deep near-infrared study of the Orion nebula, revealed a high circular polarization region is patially extended around the massive star-forming region, the BN/KL nebula, and which is being irradiated by polarized radiation inducing a asymmetric photochemistry and thus what appears to be homochirality, i.e. the production of left handed amino acids . Amino acids lead to proteins and DNA.
Interstellar molecular clouds appear to serve as stellar nurseries for building complex molecules, producing sugars, alcohols, ethers and quinons which also absorb UV and other types of radiation which would be destructive to amino acids. However, at the same time, hydrogen, oxygen, carbon, sulfur, nitrogen and phosphorus are continually irradiated by ions, and which could generate complex organic molecules, carbon grains, oxides, and even proteins
Within a nebular cloud, complex organic molecules can be provided all the ingredients necessary for building more complex molecular structures, including amino acids and proteins which can be combined to create additional life-related structures, including DNA. Even energy is supplied. 
The combination of hydrogen, carbon, oxygen and nitrogen, cyanide and several other elements, could possibly create adenine, which is a DNA base, whereas oxygen and phosphorus could ladder DNA base pairs together. Therefore, the building blocks for DNA may have also been generated within interstellar clouds.

Thus, DNA would become part of this molecular-protein-amino acid complex.

Further, these combinations would be buffeted by cosmic shock waves from additional supernova which in turn could provide these coalescing organic molecules and strands of DNA with heat and additional sources of energy. This energize DNA-molecular-protein complex could then begin to function as a proto-organism with all its needs provided by the nebular environment. The next step would be: microbial life.

Therefore, interstellar environments may have served as nuclear wombs of life (Joseph and Schild 2010). Thus, after several billion years within nebular environments which are constantly being resupplied with energy and all the necessary ingredients for life, self-replicating proto-cellular organisms, equipped with DNA, would likely be fashioned, giving rise to life. Therefore, it can be predicted that the generation of life may be an ongoing phenomenon in the oldest of nebular clouds.

However, only one replicon had to be jumbled together and energized. Once it became functional it would have immediately began replicating and creating variable copies of itself and its DNA.

At some point in the history of life, these replicons and their genomes became increasingly complex and they evolved into single celled organisms; and this evolutionary step may have also taken place in space. In fact it has been repeatedly demonstrated that microbes can survive conditions in space, including ejection from and the crash landing onto a planet, the frigid temperatures and vacuum of an interstellar environment, and the UV rays, cosmic rays, gamma rays, and ionizing radiation they would encounter (Burchell et al. 2004; Burchella et al. 2001; Horneck et al. 2001a.b, Horneck et al. 1994; Mastrapaa et al. 2001; Nicholson et al. 2000).

Microbes born on this planet are already pre-adapted for journeying through space, living in space, and not just surviving but flourishing in radioactive environments where they are continually exposed to radiation by ions similar to what might be encountered in a nebular cloud.

In 1958, physicists discovered clouds of bacteria, ranging from two million bacteria per cm3 and over 1 billion per quart, thriving in pools of radioactive waste directly exposed to ionizing radiation and radiation levels millions of times greater than could have ever before been experienced on this planet (Nasim and James, 1978). The world's first artificial nuclear reactor was not even built until 1942. Prior to the 1945, poisonous pools of radioactive waste did not even exist on Earth. And yet, over a dozen different species of microbe have inherited the genes which enable them to survive conditions which for the previous 4.5 billion years could have only been experienced in space. These radiation-loving microbes include Deinococcus radiodurans, D. proteolyticus, D. radiopugnans, D. radiophilus, D. grandis, D. indicus, D. frigens, D. saxicola, D. marmola, D. geothermalis, D. murrayi.
Microbes from Earth are preadapted to surviving conditions which they have not encountered on this planet. Therefore, they must have inherited the genes which made survival in space possible; and this means these genes were acquired from microbes which had lived in space (Joseph 2009a). It is this adaptation which made them the perfect vehicle for spreading the genetic seeds of life throughout the cosmos.
Proto-life and then microbial life has been forged in nebular clouds. Given the turbulent nature of these nebular clouds, however,  it might seem that life would be instantly destroyed unless provided some protection against the life-neutralizing hazards that would be encountered in a free-floating environment constantly exposed to conditions deadly to life. This protection would in fact be provided by the same stellar mechanisms which dispersed those elements necessary for the establishment of life. Not just the seeds of life, but the material for the creation of new stars and planets are dispersed by these powerful supernovas.
Casey Kazan via cosmology/com

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