Thread by @AlabasterDiadem

Wow! My following went up literally by like 25% in one day. Please if you could all take a gander at my sticky, that would be great, whereby I am (AFAIK) the only person to do off-the-cuff math illustrating how bogus a 100% natural #furincleavagesite is in #SARSCoV2origins

threadreaderapp.com/thread/1339682…

and remember, the FCS itself is ectopic, and NO OTHER member of that sarbecovirus clade has one.

See Page 7: ncbi.nlm.nih.gov/corecgi/tilesh…

Additionally, as our ever-knowledgeable @Daoyu15 has repeatedly pointed out, all decent alignments of "FCS containing" coronaviruses that have been discovered after the pandemic such as #RmYN02 doesn't actually have an FCS...

https://twitter.com/Daoyu15/status/1371622187052896259?s=20

all attempts to demonstrate that sarscov2's FCS is natural are bogus (so far...)

ncbi.nlm.nih.gov/pmc/articles/P… Whoops, just see this figure

So let's say it happens piecemeal and occurs over generations of viral replication.But single indels would cause #frameshifts or premature stops (#nonsense mutations). SO it means that 1 entire codon of 3 nucleotides needs to be inserted OR at the very least, 1 insertion needs...

to be compensated by a deletion elsewhere in the #ORF that doesnt cause a frameshift or other deleterious mutation. so either 2 rare mutations or all three (of the exact nts needed to construct a furin cleavage site, barring the even more mathematically impossible....

event of randomly inserting and then transition mutating into the appropriate nt ) need to occur in one transcript and then that transcript needs to turn into virus that eventually gets into a new host and replicates there, undergoing the same processes to fully complete the site

absolutely mathematically not happening in less than 100 years naturally on bat populations less than 10,000 individuals, based on any spike that can bind ACE2

when you put it in context of what actually happened, in each transcript, the more thermodynamically favorable event is 2 insertion mutations to avoid frameshifts/premature stops to just to get 1 out of the 12 nts for the #FCS.

so, not counting where the FCS is NOR the exact..

nt's needed NOR that its all sequential... it's actually ((1*10^-6)/5)^24 (sorry in my sticky i underestimated how rare it is! i wrote 1e-5 previously, that was a typo!)

1.677722e-161 (aka not happening within the lifespan of the universe, probably the most unlikely thing ever)

@JamieMetzl i swear to god you better have included my math in your interview....