BF2S Forums D&ST - Science

uziq wrote:

every tense or aggressive situation i’ve been in at parties or bars/clubs has had a heavy alcohol component.

conversely, when you go the sort of club where everyone only buys water (hint hint), there’s smiles all round and an overwhelmingly positive atmosphere. i don’t know why anyone going out dancing for an evening would drink alcohol and become sluggish and given to volatility when they could take MDMA.

/shrug

uziq wrote:

every tense or aggressive situation i’ve been in at parties or bars/clubs has had a heavy alcohol component.

conversely, when you go the sort of club where everyone only buys water (hint hint), there’s smiles all round and an overwhelmingly positive atmosphere. i don’t know why anyone going out dancing for an evening would drink alcohol and become sluggish and given to volatility when they could take MDMA.

/shrug

We reconstructed the progenitor of SARS-CoV-2, the recombinant common ancestor (the recCA). We (i) inferred a maximum likelihood tree of 31 sarbecovirus genomes (SARS-CoV-2 and 30 closely related sarbecoviruses sampled from bats and pangolins) across 15 predefined non-recombinant regions (13) with IQ-TREE v2.0.7 (60), (ii) inferred the sequence of the ancestor of SARS-CoV-2 in each tree with TreeTime v0.8.1 (61), and (iii) concatenated the resulting sequences. We next inferred a maximum likelihood tree of the 787 SARS-CoV-2 taxa with IQ-TREE and performed ancestral state reconstruction with TreeTime to identify substitutions that were reversions from Wuhan-Hu-1 to the recCA across the SARS-CoV-2 phylogeny.

The most probable explanation for the introduction of SARS-CoV-2 into humans involves zoonotic jumps from as-yet undetermined, intermediate host animals at the Huanan market (34, 38, 39). Through late-2019 the Huanan market sold animals that are known to be susceptible to SARS-CoV-2 infection and capable of intra-species transmission (40–42). The presence of potential animal reservoirs, coupled with the timing of the lineage B primary case and the geographic clustering of early cases around the Huanan market (39), support the hypothesis that SARS-CoV-2 lineage B jumped into humans at the Huanan market in mid-November 2019.

[...]

Other coronavirus epidemics and outbreaks in humans, including SARS-CoV-1, MERS-CoV, and, most recently, porcine deltacoronavirus in Haiti, have been the result of repeated introductions from animal hosts (45–47). These repeated introductions were easily identifiable because human viruses in these outbreaks were more closely related to viruses sampled in the animal reservoirs than to other human viruses. However, the genomic diversity within the putative SARS-CoV-2 animal reservoir at the Huanan market was likely shallower than that seen in SARS-CoV-1 and MERS-CoV reservoirs (45, 46, 48). Hence, even though lineages A and B had nearly identical haplotypes, their MRCA likely existed in an animal reservoir. The ability to disentangle repeated introductions of SARS-CoV-2 from a shallow genetic reservoir has previously been shown in the early SARS-CoV-2 epidemic in Washington state, where two viruses, separated by two mutations, were independently introduced from, and shared an MRCA in, China (figs. S23 and S30 and supplementary text) (11).

Successful transmission of both lineage A and B viruses after independent zoonotic events indicates that evolutionary adaptation within humans was not needed for SARS-CoV-2 to spread (49). We now know that SARS-CoV-2 can readily spread after reverse-zoonosis to Syrian hamsters (Mesocricetus auratus), American mink (Neovison vison), and white-tailed deer (Odocoileus virginianus), indicating its host generalist capacity (50–55). Furthermore, once an animal virus acquires the capacity for human infection and transmission, the only remaining barrier to spillover is contact between humans and the pathogen. Thereafter, a single zoonotic transmission event indicates the conditions necessary for spillovers have been met, which portends additional jumps. For example, there were at least two zoonotic jumps of SARS-CoV-2 into humans from pet hamsters in Hong Kong (56) and dozens from minks to humans on Dutch fur farms (52, 53).

We show that it is highly unlikely that SARS-CoV-2 circulated widely in humans earlier than November 2019 and that there was limited cryptic spread, with, at most, dozens of SARS-CoV-2 infections in the weeks leading up to the inferred tMRCA, but likely far fewer. By late-December, when SARS-CoV-2 was identified as the etiological agent of COVID-19 (8), the virus had likely been introduced into humans multiple times as a result of persistent contact with a viral reservoir.

Last edited by uziq (2022-07-27 03:14:39)

Literally nothing there to say it didn't pass through the lab

Last edited by uziq (2022-07-27 03:27:20)

uziq wrote:

why in the fuck would an animal host or 'single source' (that's not what the article says) that was experimented on at a wuhan lab end up in a food market?

Last edited by Dilbert_X (2022-07-27 03:30:23)

Dilbert_X wrote:

But its known that Chinese labs were in the habit of selling used lab-rats to food markets. Amazing eh?

Last edited by uziq (2022-07-27 03:34:11)

Last edited by uziq (2022-07-27 03:49:43)