Spent yesterday mostly bass fishing so Im just reading some of the latest .
Really If you dont understand what the Miller/Urey (and subsequent) experiments produced, ty not to eny wht theyve done in less than 50 years what happened on aerth in half a BILLION years.
You mentioned incredulity about D versus L amino acids and proteins.
You should o some more reading about how "enantiomeres " and Chirality is evidenced from all over the universe.
NASA is a good place to start. They have a series of R&D quarterlies from the National Labs where quite a bit of research has gone on into L/D relationships of Amino acids and sugars in prebiotic molecules. Evidence isnt that magical. Its somewhat prosaic biochemistry.(like L sugars are unstable and any D amino acids have not been able to link with L sugars in biotic molecules). Or, we have at least 2 meteorites that have been studied for biochemicals and while most all amino acids were at a higher ratio of L to D, and at least one, aspartic acid, is found in all enzymes in use by animals. Aspartic acid L rotation is at least 6 times greater than the D's, and the D sugars with which the amino acids link are the much more chemically stable L enantiomeres.
Not all evidence jumps out and screams at you, much of it requires connectivity to other , often unrelated, pieces of evidence . (Like why does life prefer C12 over C1). That too is a rather dull bit of evidence.
Going back out Bass fihing toay. If e dont catch anything by 11, Im comin in and will go photographing a cow of which Im doing a cartoon portrait. Ill catch up tonite or tomorrow.