Here is one reason I don’t think life as we know it is the result of ordinary processes.
In the genetic code, a stop codon (or termination codon) is a nucleotide triplet within messenger RNA that signals a termination of translation. Proteins are based on polypeptides, which are unique sequences of amino acids. Most codons in messenger RNA (from DNA) correspond to the addition of an amino acid to a growing polypeptide chain, which may ultimately become a protein. Stop codons signal the termination of this process by binding release factors, which cause the ribosomal subunits to disassociate, releasing the amino acid chain. While start codons need nearby sequences or initiation factors to start translation, a stop codon alone is sufficient to initiate termination.
Now what happens when there is no stop codon?
A nonstop mutation is a point mutation that occurs within a stop codon. Nonstop mutations cause the continued translation of an mRNA strand into an untranslated region. Most polypeptides resulting from a gene with a nonstop mutation are nonfunctional due to their extreme length.
Nonstop mutations have been linked with several congenital diseases including congenital adrenal hyperplasia, variable anterior segment dysgenesis, and mitochondrial neurogastrointestinal encephalomyopathy.
In other words, it would be bad juju if there are no means of reading of DNA and recognizing where one gene ends and the other begins. In fact, without stop codons, it looks like a DNA-RNA-protein-based life on Earth would be dead.
One could postulate a DNA-RNA-protein-based life that had an alternate stopping mechanism that eventually evolved a stop codon. But that just moves the problem elsewhere in as much as a DNA translation system that contains multiple genes needs a gene delimiting mechanism. A stopping mechanism needs proteins to implement it, but without a stopping mechanism to implement proteins, there is no stopping mechanism. We have then a chicken and egg paradox.
One could postulate proteins arose by a method outside of DNA translation and somehow recruited DNAs and RNAs and then defied all probability and somehow figured out how to code the next generation of proteins using DNAs that just happen to be coding the proteins like the ones that miraculously recruited them. At some point, such scenarios are so out of the ordinary they are not distinguishable from miracles.
Some will argue Darwinian evolution in the origin of life. That’s problematic for at least two reasons.
1. even most evolutionists don’t view the origin of life and origin of the protein translation cycle as part of typical evolutionary theory. So in that sense of the word “evolution”, stop codons didn’t evolve.
2. something dead can’t evolve by Darwinian mechanisms, and if this is an origin of life scenario we’re dealing with dead pools of chemicals.
So Darwinian evolution isn’t a solution. Chemistry isn’t a solution. Physical laws aren’t a solution. Probability isn’t a solution. In fact what we know of physical process would work against evolution of stop codons, not for it. Hence stop codons and life that depend on stop codons did not arise out of ordinary physical processes.