Is Eugene Koonin's probabilistic argument for the necessity of a multiverse to explain the origin of life sound?

Question

About Eugene Koonin

Eugene Koonin, Ph.D.
NIH Distinguished Investigator
Evolutionary Genomics Research Group
NLM/NCBI

Dr. Koonin graduated from Moscow State University, Moscow, Russia and received his Ph.D. in Molecular Biology from the same University in 1983. He has been working in the fields of Computational Biology and Evolutionary Genomics since 1984. Dr. Koonin moved to the US in 1991, first, as a Visiting Scientist, and then, since 1996, as a Senior Investigator at the National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD. Dr. Koonin's group performs research in many areas of evolutionary genomics.

Sources:

• https://irp.nih.gov/pi/eugene-koonin
• https://www.ncbi.nlm.nih.gov/research/groups/koonin/

The paper

On May 31, 2007, Eugene Kooning published the paper The cosmological model of eternal inflation and the transition from chance to biological evolution in the history of life (https://link.springer.com/article/10.1186/1745-6150-2-15) in the journal Biology Direct.

The Background section of the paper says:

Recent developments in cosmology radically change the conception of the universe as well as the very notions of "probable" and "possible". The model of eternal inflation implies that all macroscopic histories permitted by laws of physics are repeated an infinite number of times in the infinite multiverse. In contrast to the traditional cosmological models of a single, finite universe, this worldview provides for the origin of an infinite number of complex systems by chance, even as the probability of complexity emerging in any given region of the multiverse is extremely low. This change in perspective has profound implications for the history of any phenomenon, and life on earth cannot be an exception.

Eugene also includes an appendix entitled Probabilities of the emergence, by chance, of different versions of the breakthrough system in an O-region: a toy calculation of the upper bounds. I will quote an excerpt, so please refer to the paper to read the full appendix:

A ribozyme replicase consisting of ~100 nucleotides is conceivable, so, in principle, spontaneous origin of such an entity in a finite universe consisting of a single O-region cannot be ruled out in this toy model (again, the rate of RNA synthesis considered here is a deliberate, gross over-estimate).

The requirements for the emergence of a primitive, coupled replication-translation system, which is considered a candidate for the breakthrough stage in this paper, are much greater. At a minimum, spontaneous formation of:

• two rRNAs with a total size of at least 1000 nucleotides

• ~10 primitive adaptors of ~30 nucleotides each, in total, ~300 nucleotides

• at least one RNA encoding a replicase, ~500 nucleotides (low bound)is required. In the above notation, n = 1800, resulting in E <10^-1018.

In other words, even in this toy model that assumes a deliberately inflated rate of RNA production, the probability that a coupled translation-replication emerges by chance in a single O-region is P < 10^-1018. Obviously, this version of the breakthrough stage can be considered only in the context of a universe with an infinite (or, in the very least, extremely vast) number of O-regions.

In brief, Eugene appears to be saying that abiogenesis, even when conceding very generous assumptions, is virtually impossible from a probabilistic standpoint, unless we have a multiverse with an infinite (or at least a hugely vast) amount of O-regions.

Did I understand Eugene's point correctly, and if so, are his math and argument sound?

Answer 1

There are two main problems here:

1. The logic assumes that a complete, simplified ribosome is the simplest possible useful unit, so has to spring up by a series of random events. This is extremely unlikely. But, if we assume there to be benefits to some of the intermediate states, so that they become the dominant form of self replicating molecule, those odds go way down. Some educated guesses as to what the useful intermediate states might be:

   • A simple enzyme to bolt amino acid residues onto RNA. This would allow RNA enzymes to access extra chemistry, some of which might allow the formation of cell membranes, another necessary precursor. This could be non specific, assigning them randomly, in a very inefficient process

   • The proto transfer RNAs above could be functional, but could also possibly bind randomly to a RNA strand, initially, without needing the large machinery of the ribosome. It'd produce at least 2 non functional proteins for every functional one, but maybe that's fine, if no other organism can use these amino acids floating around. Or, the RNA molecule is simply using amino acids as an energy store, so forming and breaking random chains is useful in some way.

   • There might be a stabilising RNA for the proto TRNAs, which might, eventually, go on to be our first ribosome.

2. It assumes this is the only way a ribosome could have developed. The possible solution space for a molecule of some sort being able to synthesize proteins is pretty vast. There's no requirement for it to be a ribosome.

In support of the first point, this is commonly what we'd see if, say, we introduce a bacterium to a new substrate - the first forays into that new substrate are grossly inefficient, but the bacterium thrives because it is the only organism that can use the new substance. Then, we see major selection pressures to make more efficient use of the resource, and we get some incredibly efficient piece of molecular machinery. The first self replicating RNA to be able to use amino acids, as anything from an energy store to a way of getting through lipids, would have a really good chance of going on to replicate a lot more. From there, the machinery for protein synthesis starts.