Frankenstein or a Submarine Alkaline Vent: Who is Responsible for Abiogenesis?

Abstract

We argued in Part 1 of this series that because all living systems are extremely far-from-equilibrium dynamic confections of matter, they must necessarily be driven to that state by the conversion of chemically specific external disequilibria into specific internal disequilibria. Such conversions require task-specific macromolecular engines. We here argue that the same is not only true of life at its emergence; it is the enabling cause of that emergence; although here the external driving disequilibria, and the conversion engines needed must have been abiotic. We argue further that the initial step in life's emergence can only create an extremely simple non-equilibrium "seed" from which all the complexity of life must then develop. We assert that this complexity develops incrementally and progressively, each step tested for value added "in flight." And we make the case that only the submarine alkaline hydrothermal vent (AHV) model has the potential to satisfy these requirements.

Green Rust: The Simple Organizing &lsquo;Seed&rsquo; of All Life?&nbsp;&nbsp;<strong> </strong>

“…[125,147] However, as we have argued, endergonic reactions (a positive DG) can't be made to happen by mere catalysis, which can only reduce an activation energy, so mere catalysis cannot explain the emergence of life. [3,6] We need instead, nanoscale disequilibrium converters situated at the margins of the alkaline hydrothermal mound to take advantage of the various gradients imposed by the precipitation of relatively insoluble inorganic entities. This seems a tall order: that one or more of such mineral microcrystals might also act as the thermodynamic conversion engines driving emergent metabolism in the sense of Cottrell seems counter intuitive, viz., "The most promising path to solving this riddle appears at present to be through investigating whether" their local redox-state effects on gallery conformation, especially in green rust, could drive the needed proto-biosynthetic reactions while retaining their overall integrity.…”

“…[1,3,4]. Redox and pH gradients were required, together with 'engines of disequilibria conversion' to allow these gradients to do the work of surmounting the steep endergonic barriers encountered by C1 molecules that they might react and complexify along the pathways and, eventually, around the autocatalytic cycles of life, just as the autotrophs feeding the base of the food web do today.…”

“…And the precipitate mounds could provide the conversion engines specific to the transformations that needed to be made in the ambient environment, sufficient to drive life's emergence. [3,4,6] But it became clear that mere porous cavities could not provide the low water activities and the pumps beyond the merely osmotic, to take on the requirements of an autotrophic metabolism, let alone its need for adaption, guidance and waste disposal. Moreover, a mineral seed has struck many as lacking the versatility of organic molecules whatever their provenance.…”

“…[6] These engines might effect 'free energy' conversions of various types driven by Brownian motion with built-in escapement mechanisms that prevent back reactions. [3,4,13 ] It is in this light that it should be possible to discern such recognizable mineral precursors in the geologic record to explain the autogenic emergence of metabolic pathways and cycles supplied from the simplest of carbon substrates, carbon dioxide, formate and methane. [14] In the AHV model, the complex molecular engines mediating present-day electron transfer and conversions are a result of evolution from such abiotic mineral ancestors.…”

“…[14] In the AHV model, the complex molecular engines mediating present-day electron transfer and conversions are a result of evolution from such abiotic mineral ancestors. [3,4,13] Thus, the nub of this contribution is to suggest how green rust (~[Fe 2), precipitated as the first response to the alkaline vent-versus-ocean interfacing, may have been co-opted, adapted and systematized as nano-engines and catalysts at a Hadean submarine alkaline mound, so enabling the emergence of life. [15,16] That green rust is capable of conformational changes during oxidative-reductive and protonation-deprotonation oscillations lends itself to such investigations.…”