What is the origin of life on Earth?

Discussion in 'Biology & Genetics' started by valich, Oct 10, 2005.

  1. valich Registered Senior Member

    Yes. Mark this one in your diaries everyone. I, unlike others, am always ready to admit when I am wrong. Are you Ophiolite? Apparently not! The brain, like an organism, continuously evolves. Just like evolution: evolution of the mind.
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  3. valich Registered Senior Member

    Read my and CharonZ's post on "RNA/pre-RNA world and open thermodynamic systems" and my original post on "Self-reproducing Systems and the Origin of Life" which I will repost here, because we have already gone way beyond the Miler-Urey experiments in understanding the origin of life:

    Self-reproducing systems are fundamental to the origin of life. The production of ATP (adenosine triphosphate), the basic energy molecule in life on Earth, is an example of such a self-reproducing autocatalytic system.

    The Belousov-Zhabotinskii reaction (1951) is also self-replicating autocatylitic ocillating system; however it involves only inorganic chemicals. Therefore the search is on to find the "missing link" to a self-replicating organic autocatalytic system.

    Early experiments have shown that organic chemicals can be created through self-replicating systems. For instance, the Formose Reaction is a self-replicating autocatylitic reaction system where glycoaldehyde reacts with formaldehyde to produce glycerolaldehyde, that then reacts again with formaldehyde producing a sugar, that then splits the molecule into two glyceroaldehyde molecules, and the cycle continues.

    The basis of life involves just such a reaction in which basic sugars are transformed into other sugars in the metabolic self-replicating network. ATP may not have been the necessary energy carrying molecule used for the basis for the origin of life. We can postulate other energy carriers and metabolic pathways. Nucleotides and nucleicacids have already been experimentally created that contain phosphate groups. Therefore it can no longer be accepted that the formation of a phosphate molecule could not have occurred in the pre-RNA world, nor can it be accepted that the formation of a phosphate sugar enzyme, such as phosphofructokinase, could not have also occurred under early Earth pre-biotic conditions (phosphofructokinase is at the center of the control cycle for the glycosis/citric acid cycle producing ATP).

    An allosteric control system, such as the glycosis cycle, is an example of an evolutionary structure that would've been necessary for the origin of life. Glycosis and fermentation are of the most ancient self-replicating autocatylitic systems known that created pathways within organisms. Natural selection could have then refined these pathways to evolve the evolutionary diversity in life we see today.
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