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the barriers to abiogenesis become much smaller.

Yep, they become 10^39,999

Read the experiment on the 32 residue peptide. It was a designed peptide. Apparently it was split into 2 - 16 residue halves of single chirality(both types) for a total of 4 chunks.

The researchers used four different peptide fragments, each containing only D- or L-amino acids. Four different products were in principle possible: two homochiral, comprised of only D- or L-amino acids, and two heterochiral, made from two differently handed fragments.

But on mixing the fragments, the researchers obtained predominantly homochiral products. Once formed, the homochiral molecules acted as templates, accelerating their own replication, the team says. The heterochiral molecules, in contrast, did not use this ploy to compete.

Here are the odds.

The specific 16 residue peptide(20aa universe) with heterochirality --- 20¹⁶ = 6.5536E+20

The specific 16 residue peptide with homochirality --- 39¹⁶ = 2.8644E+25 (glycine is not chiral)

The specific 32 residue peptide with homochirality --- 39³² = 8.20479E+50 (glycine is not chiral) and both parts are necessary for the creation of the whole.

Now the "self-replication" consists of joining two 16 residue halves together. This produces the designed peptide which then "catalyzes" the formation of further molecules of the 32 residue peptide. Well, as you can see the likelyhood of the two 16 residue pieces coming into existence is about 1 in 3E20. So to see how this experiment would work you must mix the homochiral parts to heterochiral parts in the ratio of 1 homo to 3e20 heteros. This is not a very good ratio for the procreation of the homos. This must also be viewed in relation to the pieces and parts of peptides of length 1 to "as long as a peptide can get in the just-so environment created by the Darwininian". (these other peptides will be competing for the goodies in the prebiotic soup).

Actually, I made a mistake and grabbed the wrong number. The homo/hetero ratio should be 1 to 1.4E25. The mass of the earth is about 5.9736*10²⁴. So take one kilogram of homo and mix it with the earth's weight of hetero and you will get about the right proportion.

likelihood=likelyhood.
Spell check flatulence. Must be the homo/hetero influence.

Good post.

I assume you're referring to this paper? If I read this figure from the paper correctly, the peptide's sequence is:

RVKQLEKKVSELLKKVACLEXEVARLKKLVGE

... which I read as 12 amino acids. So while I'm out doing some Lightbulb Day shopping, could you please restate your calculations assuming a 12 amino acid universe?

Or not. Your calculations have two more problems right out of the gate, IMO:

We don't know how many variations on that specific sequence also exhibit the property, so we don't know how big the island of viability is within its sequence space.
We don't know how much of a bias there was towards the present chirality. We do know that nebulae contain amino acids, more of which are the "correct" chirality, and we know that certain mineral surfaces help separate out amino acids of different chiralities, and we know that amino acids of the "wrong" chirality are (very slightly) less stable than those of the "right" chirality.

As for the calculations themselves, I'll have to chew on them for a while. I'm not sure what exactly you're trying to claim about them.