Here be Dragons (Searching a large "Phase Space")

 

https://barryhisblog.blogspot.com/p/here-be-dragons-searching-large-phase.html

Our bodies are mostly made up of proteins, which are, in, turn, made from strings of smaller molecules, amino acids. There are very many different proteins, from between an estimated 80,000 and 400,000, but they are all made up of different strings of amino acids, normally just 20 different types. However, like letters in text, they can form an utterly huge number of "words", albeit most of them being meaningless "words".

Each type of amino acid is originally specified by a group of three bases from the DNA. Each triplet of bases is called a "codon".

In the cdesign proponentsist "literature" (see https://ncse.ngo/cdesign-proponentsists), the probability of nature finding a particular useful protein is claimed to be such a small one that it can be safely discounted, therefore any useful protein must have been made, either by an unnatural magic man using ju-ju, or by an unidentifiable flying intelligent designer.

It is a straw-man argument. Straw-man arguments are, at best, mistaken, and at worst, deliberately misleading.

The straw-man argument here is that the number of potential proteins is so huge that stabbing in the dark to find a useful protein among all the meaningless ones is prohibitively unlikely.

Why is it a straw-man? Because randomly stabbing in the dark cannot be the way in which useful proteins come about. 

Below is figure 5.2 from Jason Rosehouse's "Failures of Mathematical Evolutionism" (https://www.amazon.com/Failures-Mathematical-Anti-Evolutionism-Jason-Rosenhouse-ebook/dp/B0B523NRCB/)

"Protein space" is merely the complete collection of the different possible proteins there are. In our visualisation of them, they are set out in an organised "phase space" where adjacent proteins differ by just one amino acid. It is a multi-dimensional phase space, but if you can't get your head around that, don't worry. The diagram is an analogy, showing just two dimensions. The important thing to grasp is that the closer two points are, the more similar the proteins are, differing by only one or a few amino acids. Hopefully the figure is sufficient to get the principle across. 

Figure 5.2 Searching protein space. The solid black dot at the intersection of the axes represents the origin of life. The other solid black dots represent protein stepping stones connecting an ancient protein to more modern forms. The gray circles show that evolution only examines the local area near an already existing protein and completely disregards the rest of the space.

It is proposed that at the origin of life, represented by the graph - er - origin, the first life forms were simple enough to have come about by basic chemistry, being more likely to emerge than more complex forms. I call something that would qualify in that way a first "evolver". An evolver is an entity that can reproduce and pass down its specification to its offspring, with variations that can be subject to selection. The variations that make it better at reproducing themselves will become represented more and more frequently as the generations pass.  

Evolution is off and running.

What do you think would be the simplest, most probable evolver to emerge naturally? I don't know either. Nobody does. But it would only take one. Genesis says it happened. The earth and the waters brought forth life.

Anyway, as evolution proceeds, the entire "space" of possible amino acid sequences is not searched for by the natural selection of heritable variants. What is searched for are small variations in the existing sequence that are caused by mutations to the DNA codons. The "Here be dragons" brings to mind medieval maps with their unexplored areas. They are not (yet) "explored" by those variations.

The fact that only a small "space" of variations is explored increases enormously the probability that improvements will be found.

The crude "stab in the dark" straw-man caricature of naïve creationist probability "models" does not take into account the evolutionary process, and so misses the mark entirely.


See also, https://barryhisblog.blogspot.com/p/probability-emo.html