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The Chimera section claims: > Pangolins and bats don't usually cohabitate, making this somewhat unlikely in nature. Horseshoe bats are nocturnal animals that

The Chimera section claims: > Pangolins and bats don't usually cohabitate, making this somewhat unlikely in nature. Horseshoe bats are nocturnal animals that roost in caves during the day but sometimes practice perch feeding at night [1]: > The other strategy is known as perch feeding: Individuals roost on feeding perches and wait for prey to fly past, then fly out to capture it. Pangolins [2] and palm civets [3] are nocturnal and arboreal. The bat viral RNA sequences come from anal swabs of netted animals so they are primarily gastrointestinal infections. All of these animals are found in the Lancang/Mekong [4] catch basin. Bat guano seems like a good vector for the virus. Gain-of-function experiments require two viral isolates that recombine during passage. The lab theory assumes that the RNA sequence of the original viral isolates were never shared. I find this scenario unlikely but I am open to changing my mind based on evidence. SARS-1 is evidence of a very similar zoonotic scenario. Humans that encounter bat guano in this region also seem like a good host for a recombination event. [1] https://en.wikipedia.org/wiki/Horseshoe_bat#Diet_and_foraging https://en.wikipedia.org/wiki/Horseshoe_bat#Diet_and_foragin... [2] https://en.wikipedia.org/wiki/Pangolin#Behavior https://en.wikipedia.org/wiki/Pangolin#Behavior [3] https://en.wikipedia.org/wiki/Asian_palm_civet#Feeding_and_diet https://en.wikipedia.org/wiki/Asian_palm_civet#Feeding_and_d... [4] https://en.wikipedia.org/wiki/Mekong https://en.wikipedia.org/wiki/Mekong

frombody 6y ago
SARS-CoV-2 itself is not a recombinant of any sarbecoviruses detected to date, and its receptor-binding motif, important for specificity to human ACE2 receptors, appears to be an ancestral trait shared with bat viruses and not one acquired recently via recombination. https://www.nature.com/articles/s41564-020-0771-4 https://www.nature.com/articles/s41564-020-0771-4
- sradman 6y ago
  Exactly, "detected to date". The animal surveillance programs were inadequate at the time of the outbreak and have since been defunded and shutdown altogether.
DoingIsLearning 6y ago
The official position is that the start of this pandemic was in 'Huanan Seafood Wholesale Market' in Wuhan. [0] So are you proposing that a pangolin from Lancang was transported more than 2000km to a seafood wetmarket in Wuhan? At face value, this sounds like a very unlikely scenario for a zoonotic event/origin. [0] https://www.nationalgeographic.com/animals/2020/04/coronavirus-linked-to-chinese-wet-markets/ https://www.nationalgeographic.com/animals/2020/04/coronavir...
- Widdershin 6y ago
  Maybe there’s a distinction to be had between patient zero and the first link in the chain we can reliably pinpoint.
- incrudible 6y ago
  As far as I'm aware, there is no "official" Chinese position on where and how the virus originated. Assuming a zoonotic origin in China, it's much more likely that an infected individual from rural Southern China happened to travel to Wuhan and that the seafood market just happened to be the kind of location where such a virus would spread. There is some evidence that there is a degree of immunity to COVID-19 in areas that had SARS-outbreaks. It would therefore be plausible that an initial COVID-19 outbreak in Southern China, the epicenter of SARS1, could have gone unnoticed. The actual animals sold at the market would then be irrelevant, but there's a narrative that "animal cruelty and human encroachment are to blame for COVID" that is being pushed here.
  - dathinab 6y ago
    Given that the Covid 19 outbreak in Italy (and I think France too but I'm not sure) went unnoticed(1) for well over a month this is quite likely... (1): I probably should use "unidentified", it was noticed that there was a unusual spike in pneumonia related death. It was just not linked to a "new" virus.
- bamboleo 6y ago
  Given that apparently the virus was outside China in early December already, is it possible that Wuhan was simply the first fast-spreading location rather than the place where the transmission happened? If the virus was in Milan’s sewers in December, it feels that it might as swell have started spreading there first. Likewise, Italy contained the virus from May to September, then it exploded again. Nothing particularly happened in September, yet by chance it spiked. Just speculating though, I’d like to hear others’ opinion on this thought.

frombody 6y ago

SARS-CoV-2 itself is not a recombinant of any sarbecoviruses detected to date, and its receptor-binding motif, important for specificity to human ACE2 receptors, appears to be an ancestral trait shared with bat viruses and not one acquired recently via recombination. https://www.nature.com/articles/s41564-020-0771-4 https://www.nature.com/articles/s41564-020-0771-4

sradman 6y ago
Exactly, "detected to date". The animal surveillance programs were inadequate at the time of the outbreak and have since been defunded and shutdown altogether.

DoingIsLearning 6y ago

The official position is that the start of this pandemic was in 'Huanan Seafood Wholesale Market' in Wuhan. [0] So are you proposing that a pangolin from Lancang was transported more than 2000km to a seafood wetmarket in Wuhan? At face value, this sounds like a very unlikely scenario for a zoonotic event/origin. [0] https://www.nationalgeographic.com/animals/2020/04/coronavirus-linked-to-chinese-wet-markets/ https://www.nationalgeographic.com/animals/2020/04/coronavir...

Widdershin 6y ago
Maybe there’s a distinction to be had between patient zero and the first link in the chain we can reliably pinpoint.
incrudible 6y ago
As far as I'm aware, there is no "official" Chinese position on where and how the virus originated. Assuming a zoonotic origin in China, it's much more likely that an infected individual from rural Southern China happened to travel to Wuhan and that the seafood market just happened to be the kind of location where such a virus would spread. There is some evidence that there is a degree of immunity to COVID-19 in areas that had SARS-outbreaks. It would therefore be plausible that an initial COVID-19 outbreak in Southern China, the epicenter of SARS1, could have gone unnoticed. The actual animals sold at the market would then be irrelevant, but there's a narrative that "animal cruelty and human encroachment are to blame for COVID" that is being pushed here.
- dathinab 6y ago
  Given that the Covid 19 outbreak in Italy (and I think France too but I'm not sure) went unnoticed(1) for well over a month this is quite likely... (1): I probably should use "unidentified", it was noticed that there was a unusual spike in pneumonia related death. It was just not linked to a "new" virus.
bamboleo 6y ago
Given that apparently the virus was outside China in early December already, is it possible that Wuhan was simply the first fast-spreading location rather than the place where the transmission happened? If the virus was in Milan’s sewers in December, it feels that it might as swell have started spreading there first. Likewise, Italy contained the virus from May to September, then it exploded again. Nothing particularly happened in September, yet by chance it spiked. Just speculating though, I’d like to hear others’ opinion on this thought.