I think this is fair, even if a bit frustrating that the explanation can't be broken down simpler to laymen.
Or is it a logical reality? i.e. we know the possible permutations of the RNA and from its current state it could not reach an escape branch?
Edit: FYI, my biology is weak but it has occured to me that there must be a topology of evolution.
You first spoke as if it was an absolute certainty ("This is basic evolutionary theory") and now are saying, "all of the normal caveats apply" which is exactly what I was getting at in my OP thread. The "normal caveats"/edge cases are exactly what this whole discussion is about. Clearly we are speaking past one another, I apologize for my role in whatever went wrong here.
The problem is you haven't grasped that they're actually the same answer. It can be true that a field driven by stochastic behaviour consists mostly of degrees and probabilities, and still, due to the realities of how evolution and natural selection work, mean that it is impossible for an extremely highly conserved component of spike protein to jump to a new configuration, that at the same time escapes antibody response for the conserved region and maintains any degree of fitness in the wild.
Please park your antagonism and if you are actually interested, walk through the door and explore the field yourself. It's fascinating
See this is exactly the sort of quantification I was asking for from the beginning (albeit still somewhat vague). Others in the thread have already answered most of my questions (read the other threads if you like) but you just kept talking past them until now. I appreciate you taking the time to respond.
> walk through the door and explore the field yourself. It's fascinating
That is precisely what I am trying to do here because I do find it fascinating as well. I have to be allowed to ask questions (even stupid ones) and I do those primarily in discussion forums like HN.
This is basic evolutionary theory that has been subsequently played out in both the lab and in the wild. You can't prove a negative but your requirement for reassurance will only be assuaged by furthering your own understanding of evolution on a molecular level, it doesn't seem like anything I could say to you in a reply to an internet post would make the slightest bit of difference to your skepticism and you'd have to get the basic grounding in yourself. The full answer would require 3-4 years of fulltime study, the shorter answer could be arrived at by reading the blind watchmaker and climbing mount improbably, two highly accessible books on evolutionary biology