Theoretical origin of life: need for repair (Introduction)

by David Turell , Thursday, June 27, 2024, 20:04 (126 days ago) @ David Turell

Most be present at first form of life:

https://evolutionnews.org/2024/06/new-video-life-cant-exist-without-repair-mechanisms-a...

"Damage to the “factory” of the cell occurs on two levels: damage to the stored information (either during replication or by natural degradation over time) and damage to the manufacturing machinery (either from faulty production of new machinery or damage incurred during use). Each type of damage requires specific repair mechanisms that demonstrate foresight — the expectation that damage will occur and the ability to recognize, repair and/or recycle only those components that are damaged. All known life requires these mechanisms.

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"DNA replication in all life includes a subsequent proofreading step — a type of damage repair — that enhances the accuracy by a factor of 100 to 1,000. The current record holder for the sloppiest DNA replication of a living organism, under normal conditions, is Mycoplasma mycoides (and its human-modified relative, JVCI-syn 3A), where only 1 in 33,000,000 nucleotides are incorrectly copied.

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"DNA repair is essential to maintain DNA but the genes that code for DNA repair could not have evolved unless the repair mechanisms were already present to protect the DNA.

"We used to think that the metabolic machinery in a cell always produced perfect products. But the reality is that faulty products are unavoidable, resulting in the production of interfering or toxic garbage. All living organisms must therefore have machinery that identifies problems and either repairs or recycles the faulty products.

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"...all forms of life, even the simplest,9 are capable of trans–translation, typically involving a three-step process. First, a molecule combining transfer and messenger RNA and two helper molecules (SymB and EF-Tu) recognizes that mRNA is stuck in the ribosome and attaches a label to the half-formed protein. This label, called a degron, is essentially a polyalanine peptide. The condemned protein is recognized, degraded, and recycled by one of many proteases.

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"The normal operation of enzymes or metabolites like co-enzymes or cofactors involves chemical reactions that follow specific paths. Deviations from the desired paths can occur from interferences like radiation, oxidative stress, or encountering the wrong “promiscuous” enzyme. These deviations result in rogue molecules that interfere with metabolism or are toxic to the cell. As a result, even the simplest forms of life require several metabolic repair mechanisms:

“'[T]here can be little room left to doubt that metabolite damage and the systems that counter it are mainstream metabolic processes that cannot be separated from life itself.”

“It is increasingly evident that metabolites suffer various kinds of damage, that such damage happens in all organisms and that cells have dedicated systems for damage repair and containment.

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"Because the repair proteins are themselves a product of the cell’s metabolism, this creates another path of circular causality: You can’t have prolonged metabolism without the repair mechanisms but you can’t make the repair mechanisms without metabolism.

"In addition to life’s required repair mechanisms, all forms of life include damage prevention mechanisms. These mechanisms can destroy rogue molecules, stabilize molecules that are prone to going rogue, or guide chemical reactions toward less harmful outcomes.

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"Those who promote unguided abiogenesis simply brush off all of these required mechanisms, claiming that life started as simplified “proto-cells” that didn’t need repair. But there is no evidence that any form of life could persist or replicate without these repair mechanisms. And the presence of the repair mechanisms invokes several examples of circular causality — quite a conundrum for unintelligent, natural processes alone. Belief that simpler “proto-cells” didn’t require repair mechanisms requires blind faith, set against the prevailing scientific evidence." (my bolds)

Comment: as I have shown here in the past all of OOL research is based on blind faith that life can appear naturally. This article says NO WAY. So much for RNA's alone starting life. Any cell must be a complete set of cooperating parts. Every cell division must produce two perfect DNA's. Thousands of cell divisions go on every day in every organism. All of this article applies.