Did Life Originate in Galactic Nebula? Some Experts Say “Yes”


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Over 13 billion years ago at least one of the domains of life may have begun in nebular clouds. If restricted to the Milky Way, which is 13.6 billion years old, the first chemical combinations would have had billions of years to become a self-replicating organism with a DNA genome long before the existence of Earth.

Nebular clouds are thought to be most likely environment for synthesizing and promoting the evolution of molecules needed for the origin of life. The building blocks for DNA could have been generated or combined within interstellar clouds and DNA would become part of the molecular-protein-amino acid complex. Hydrogen, oxygen, carbon, calcium, sulfur, nitrogen and phosphorus for example are continually irradiated by ions, which can generate small organic molecules which evolve into larger complex organic molecules that result in the formation of amino acids and other compounds. 

Phosphorus, for example, is rare in our solar system and may have been non-existent on the early Earth; phosphorus is essential for the manufacture of DNA.

Polarized radiation in the nebula cloud leads to the formation of proteins, nucleobases and then DNA. The combination of hydrogen, carbon, oxygen, nitrogen, cyanide and several other elements, could create adenine, which is a DNA base, whereas oxygen and phosphorus could ladder DNA base pairs. Glycine has also been identified in the interstellar clouds. 

Fast forward 4.6 billion years, on Earth the steps leading from the random mixing of chemicals to the first nano-particle would likely require hundreds of millions and even billions of years before the first self-replicating molecular compound was fashioned. Even after billions of years, the first replicon may not have possessed DNA.

The steps leading from self-replicating chemical compound to the complexity of a DNA-equipped organism, could not have taken place on Earth as all the essential ingredients were missing and there was simply not enough time. 

By contrast, it is highly likely that all the ingredients and conditions necessary for building complex molecular organic structures, amino acids and proteins are present in nebular clouds, including phosphorus, calcium, water, carbon, and oxygen which when mixed together and irradiated might easily produce self-replicating nano-crystal-particles. It can be suggested that due to turbulence, supernova, stellar ignition, and other forces, that these and other complex organic molecules were combined within nebular clouds to create life-related structures, which eventually resulted in a self-replicating nano-particle with a semi-permeable membrane.

Further, these combinations would be forged by cosmic shock waves from additional supernova thereby providing these coalescing organic molecules and strands of DNA with heat and additional sources of energy. Eventually this energized DNA-membranous-protein complex would have begun to function as a proto-organism or proto-viral replicon with all its needs provided by the chemically rich environment. 

The next steps would lead to microbial life. Once the first microbe was created, it immediately began replicating and creating billions and then trillions of variable copies of itself and its DNA.

Casey Kazan 

Sources:

cosmology.com

Hoyle, F., (1982), Evolution from Space (The Omni Lecture) Enslow Publishers, USA

Koninga, N., et al., (2008). Organic molecules in the spectral line survey of Orion KL with the Odin Satellite from 486–492 GHz and 541–577 GHz. Proceedings of the International Astronomical Union, 4, 29-30.

Kensei K., et al., (2008). Formation of amino acid precursors with large molecular weight in dense clouds and their relevance to origins of bio-homochirality. Proceedings of the International Astronomical Union, 4:465-472.

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