Originally Posted by
Skeptic Ginger
@lomiller: No it is not all recombination. That is playing a role with COVID, but it is not the only thing going on.
Yes it’s recombination. The changes to the spike protein that allow it to infect humans came from a recombination event with a Pangolin virus.
https://www.nature.com/articles/s41598-020-78703-6#Tab2
Quote:
Our analysis confirmed that the 228 bp long sequence within the SARS-CoV-2 S protein (Fig. 2A) is likely to be an integrated sequence resulting from recombination between some strains similar to Bat-CoV-RaTG13 (NCBI accession No. MN996532) and some strains similar to Pangolin-CoV-2019 (NCBI accession No. MT121216; Table 1, Fig. 1D, Figs. S1C, S2). This recombination was significant in 6 independent statistical tests (Table 1). Moreover, we further validated of this recombination by performing sliding window analysis on sequence differences (Fig. S3) between SARS-CoV-2 and other coronaviruses proximal to SARS-CoV-2 in the phylogenetic tree (Fig. 1A). The recombination event was also validated by genetic distance analyses (Table 2).
Something else to keep in mind is that RaTG13 is not a direct ancestor to Covid, but in the last year no closer relative has been found. If the direct ancestor to Covid was already in laboratories in 2019 why is so hard to find now?
One possibility as to why the direct ancestor is proving to be so hard to find is that we are looking in the wrong place. Related viruses are found across China, Japan and Southeast Asia. Interestingly Covid-19 neutralizing antibodies have been found in both bats and Pangolins at a wildlife refuge in Thailand.
https://www.nature.com/articles/s41467-021-21240-1
Originally Posted by
Skeptic Ginger
How do you know COVID 19 can't reinfect bats?
The receptor binding doesn’t attach well to bat ACE-2. While it appears Covid-19 can infect many animals, bats are actually somewhat immune. The paper you linked to waved this away as “just models”.
Originally Posted by
Skeptic Ginger
If you aren't aware the Chinese cover things up for political reasons and to 'save face' I recommend you do more reading on the subject.
As I said above, there is good evidence that local officials dragged their feet for several weeks in reporting the outbreak to the central government. How you get from here to “Covid escaped from a lab” I have no idea.