>Evolutionary origins of the SARS-CoV-2 sarbecovirus lineage responsible for the COVID- 19 pandemic
>Divergence dates between SARS-CoV-2 and the bat sarbecovirus reservoir were estimated as 1948 (95% highest posterior density (HPD): 1879–1999), 1969 (95% HPD: 1930–2000) and 1982 (95% HPD: 1948–2009), indicating that the lineage giving rise to SARS-CoV-2 has been circulating unnoticed in bats for decades.
You should also know that SARSCoV2 1) is not a chimeric virus, and 2) that the present study includes viruses linked to RaTGP13 but more distant from SARSCoV2, i.e. it includes evidence from viruses unassociated with the pandemic.
> You should also know that SARSCoV2 1) is not a chimeric virus,
There is no basis for this claim. Genomic evidence shows that SARS-CoV-2 is not a chimera of any two previously-known viruses. No possible genomic evidence could exclude a chimera of two previously-unknown viruses, and the WIV was the world's leading collector of such novel sarbecoviruses from nature. They proposed to make chimeras of them in DEFUSE. That proposal wasn't funded, but this article now reports explicit claims they did such work:
> They said the Wuhan scientists had inserted furin cleavage sites into viruses in 2019 in exactly the way proposed in Daszak’s failed funding application to Darpa.
You're basically rehashing Andersen's "Proximal Origins" here, and even he has moved on to more sophisticated (though still unconvincing) arguments like Pekar. As David Relman wrote almost three years ago:
> This argument [that SARS-CoV-2 must be natural since it doesn't use a known backbone] fails to acknowledge the possibility that two or more as yet undisclosed ancestors (i.e., more proximal ancestors than RaTG13 and RmYN02) had already been discovered and were being studied in a laboratory—for example, one with the SARS-CoV-2 backbone and spike protein receptor-binding domain, and the other with the SARS-CoV-2 polybasic furin cleavage site. It would have been a logical next step to wonder about the properties of a recombinant virus and then create it in the laboratory.
We know SARSCoV2 is not a chimeric virus because similar viruses have been identified from other locations, and the pattern-matching (sequence alignment) shows that SARSCoV2 does not have any insertions or deletions that have a different evolutionary origin compared to its close relatives.
That doesn't make any sense. I'm assuming by "chimera" that you mean, for example, the spike from natural virus A on the backbone of natural virus B. The WIV could have taken the spike from a virus similar to BANAL-20-52, the backbone from a different, unpublished virus that they'd sampled from nature, and a human-designed FCS. This is basically what they proposed in DEFUSE (in collaboration with Baric at UNC), and what this Times article is now saying they did internally after DEFUSE got rejected.
Of course such a virus could also have evolved naturally by a similar path; lots of sarbecoviruses are just a single mutation away from that FCS, and perhaps there's some yet-unknown natural animal host where that gets selected for. The point is that no genomic evidence can distinguish between these two cases, though.
For emphasis, it seems like you're assuming that we know all the natural viruses that the WIV was working with. Sampling of novel coronaviruses from nature was a core part of the WIV's research, so that's not a reasonable assumption. RaTG13 was sampled in 2013, but not fully published until 2020. At least one novel coronavirus was identified in contamination of rice samples sequenced on the same equipment that the WIV used:
That's a merbecovirus, so it couldn't possibly have any relationship to SARS-CoV-2; but if they had one unpublished novel virus, then it's hard to reject the possibility that they had more.
What about Ralph Baric's method for splicing viruses? It's apparently really hard or impossible to detect, and that's plausibly something that could be used to make a chimeric coronavirus.
>Evolutionary origins of the SARS-CoV-2 sarbecovirus lineage responsible for the COVID- 19 pandemic
>Divergence dates between SARS-CoV-2 and the bat sarbecovirus reservoir were estimated as 1948 (95% highest posterior density (HPD): 1879–1999), 1969 (95% HPD: 1930–2000) and 1982 (95% HPD: 1948–2009), indicating that the lineage giving rise to SARS-CoV-2 has been circulating unnoticed in bats for decades.
https://www.nature.com/articles/s41564-020-0771-4
You should also know that SARSCoV2 1) is not a chimeric virus, and 2) that the present study includes viruses linked to RaTGP13 but more distant from SARSCoV2, i.e. it includes evidence from viruses unassociated with the pandemic.