Hi Joshua,
I just came across the following comment by a reader named Rumraket over at The Skeptical Zone. I gather he’s a biologist. What do you think of his argument?
There actually is evidence for abiogenesis (not unassailable proof, but evidence nonetheless) of the hypothesis that life originated from non-living materials by a process of physics and chemistry. The evidence is that the inferred amino acid frequencies in the phylogenetically inferred ancestors of the oldest known proteins, increasingly correlate with the distribution of amino acids produced in abiotic chemical reactions, and predicted to result from them by thermodynamics, as we go further back in time. As one would expect if life originated by a blind, unguided physical and chemical process whereby the first proteins were synthesized by polymerization of the sorts of amino acids that existed and therefore were the only ones available in the prebiotic environment.
Brooks DJ, Fresco JR, Lesk AM, Singh M. Evolution of amino acid frequencies in proteins over deep time: inferred order of introduction of amino acids into the genetic code. Mol Biol Evol. 2002 Oct;19(10):1645-55. [PMID: 12270892]
Higgs PG, Pudritz RE. A thermodynamic basis for prebiotic amino acid synthesis and the nature of the first genetic code. Astrobiology. 2009 Jun;9(5):483-90. [DOI: 10.1089/ast.2008.0280]
Trifonov EN. Consensus temporal order of amino acids and evolution of the triplet code. Gene. 2000 Dec 30;261(1):139-51. [PMID: 11164045]
This is evidence for a physical/chemical origin of life from non-life, and evidence against intelligent design, because this is the kind of evidence you would rationally predict if life originated by a chemical and physical process from non-life. But if life originated by intelligent design, the designer could have made the first life to exist with basically any distribution of amino acids that the designer wanted . For example, the designer could have made the first life to exist with the exact same distribution of amino acids that we see in life that exists today on Earth in 2018. Yet that is not what we see. As we go further and further back in time, the proportion of amino acids used in proteins increasingly mirrors the kind of distribution of amino acids detected meteorites, space, and various non-biological chemical reactions. This distribution is also predicted by thermodynamics to result from non-biological, unguided chemistry.
I don’t think the evidence Rumraket puts forward discredits Intelligent Design, as one could always opt for a front-loading scenario. However, it does seem to be strong prima facie evidence for abiogenesis. Thoughts?