Which hypothesis has the most evidence for the origin of life: Metabolism or RNA self-replication?

The RNA World hypothesis clearly has the “most” evidence: molecular fossils in the form of nucleotide cofactors that catalyze many of the most ancient and basic biochemical reactions; the synthesis of DNA from RNA precursors; the RNA-based system of protein synthesis; the demonstrated capacity of RNA enzymes to catalyze key reactions.

But “most” is not the same as “best”. Despite decades of effort, no one has developed a plausible scheme in which RNA forms and replicates faster than it breaks down. RNA simply isn’t stable in aqueous solutions. Thermodynamics dictates that hydrolysis will always be favored absent an exogenous source of energy.

And that, really, is the basis of the argument that metabolism preceded RNA self-replication. Or, as Nick Lane puts it in “The Vital Question”, that energy precedes information.

Put this way, the answer is pretty obvious – in a universe dominated by the 2d and 3d laws of thermodynamics, information cannot exist stably without an input of energy.

Lane’s scheme for how energy metabolism arose (proton gradients in alkaline hydrothermal vents) is ingenious and also explains why all cells use proton gradients to generate energy.

Unfortunately, no one, including Lane, has come up with a compelling demonstration of his hypothesis. It could be that Lane is wrong about the specific origin of energy metabolism or (as I believe) that there is “something else” that is necessary but has yet to be discovered.

The RNA World was (and is) real. It was surely as stage of the evolution of life. I just don’t think it was THE ORIGIN. “Energy precedes information” is a simple argument, but an utterly compelling one, and I am sure it is correct.