Angela Rasmussen is indeed a virologist and is heavily quoted in the media, but this appears to be more because she specifically seeks that (she has a publicist!) than due to any prior distinction.
Ralph Baric invented modern coronavirology. He was Zhengli Shi's mentor, and published frequently with her in the past. He signed Jesse Bloom's and Alina Chan's letter in Science calling for further investigation of the origins of SARS-CoV-2:
As to the specific tweet that you've linked, David Baltimore seems to disagree:
> “When I first saw the furin cleavage site in the viral sequence, with its arginine codons, I said to my wife it was the smoking gun for the origin of the virus,” said David Baltimore, an eminent virologist and former president of CalTech.
My own impression is that the FCS points only weakly towards lab origin (and other evidence, like the origin city, lack of intermediate host, and pre-adaptation to humans is much more significant), but I'm not the one with the Nobel prize. But my point is that if you choose experts by almost any metric other than Twitter follower count, you'll see a very different picture.
> Ralph Baric invented modern coronavirology. He was Zhengli Shi's mentor, and published frequently with her in the past. He signed Jesse Bloom's and Alina Chan's letter in Science calling for further investigation of the origins of SARS-CoV-2:
I read the Science article; the way it was drafted doesn't really specifically rule any particular thing out however. It's just calling for a further investigation, and says that both hypotheses remain "viable", which is an extremely low bar in science.
Combing Jasnah's thread with another by Andersen (https://twitter.com/K_G_Andersen/status/1391507230848032772), it paints a picture that any explicit engineering seems a bit far fetched. I have yet to seen any specific responses to these critiques of lab engineered FCN site hypothesis. Instead, I see mountains of people who are not in a position to critically evaluate these claims. Science is both an institution and a process, and not everyone is equally qualified to evaluate the evidence.
That letter may seem perfectly tepid and reasonable out of context, but Andersen has publicly criticized it:
> But, “the letter suggests a false equivalence between the lab escape and natural origin scenarios,” he said. “To this day, no credible evidence has been presented to support the lab leak hypothesis, which remains grounded in speculation.”
Dr. Shi too (though she obviously can't deviate from the CCP's position without putting herself in physical danger):
> The chief scientist for emerging disease at the Wuhan Institute of Virology, Shi Zhengli, said in an email that the letter’s suspicions were misplaced and would damage the world’s ability to respond to pandemics. “It’s definitely not acceptable,” Shi said of the group’s call to see her lab’s records. "Who can provide an evidence that does not exist?"
The controversy isn't "people who don't think lab origin merits further investigation" vs. "people who don't think natural origin merits further investigation". It's between people who think lab origin is so unlikely that no further investigation of that possibility is necessary (like Andersen and Rasmussen, along with the CCP), vs. people who think both possibilities are sufficiently likely that further investigation of both is required (like Chan, Bloom, Baric, Tedros, Redfield, etc.), as expressed in that letter. I'm obviously with the latter group. For example, I believe we should push China to release more records from the WIV, but I also believe we should keep sampling animals looking for a natural intermediate host. If you study the evidence yourself then I believe you will agree.
As I noted above, as best I can tell the FCS is mostly a distraction--interesting, but not determinative either way. (Although again, a Nobel prize winner seems to disagree with me.) I'm much more convinced by the origin city and distinctive nature of the WIV's work sampling novel viruses from nature, by the lack of an intermediate host, by China's removal of access to the WIV's database of viral genomes in September 2019, by their blocking reporters from the mine where RaTG13 was discovered, and other such non-genomic evidence. This evidence is also much easier to judge without advanced scientific background.
ETA: And for emphasis, "no genetic engineering" also doesn't imply "no lab origin". For example, it's entirely possible that SARS-CoV-2 is a naturally-evolved virus accidentally released by the WIV. They routinely sampled remote, virus-rich bat caves that no other human would enter, with nothing more than a surgical mask and nitrile gloves. They could easily have brought a virus back to Wuhan and released it before even sequencing it, whether in a lab accident there or in a researcher who became infected in the field. I urge you to research and understand this yourself, instead of deferring to strawmen set up by virologists with little distinction beyond their Twitter following.
ETA2: And note that Andersen and Rasmussen both now claim to support further investigation, but prior to the Science letter they did not. They also seem to support it only in the abstract, and to shout down any calls for specific actions (e.g., pushing China to release the WIV's virus database). This is a long story; please try to understand it in detail, and don't take any isolated claim from any side at face value.
Nobel peace prize winners can been frankly weirdly wrong on these topics when they overextend from their own specific domain. Think back to the AIDs crisis, where Peter Duesberg, an award winning molecular biologist, thought that AIDs couldn't possibly be caused by HIV. He was outside of his peer group that came to realize that AIDs is in fact caused by HIV. Experts can be wrong, but that is why science is not just a process, but an institution. Peer review is how we deal with these discrepancies, and "doing your own research" without expert mentorship is not a substantial substitute.
I have a PhD in bioinformatics, and yet I know that my personal expertise (and ability to consume) information about viral engineering is limited. I therefore have to rely on experts, and make a substantial effort to tune my priors to ensure I'm listening to the right sources. A single medium blog from a reporter without any editorial supervision is not an adequate substitute. When I have questions about how to adjust my priors for this subject, I have been in communication with colleagues whose expertise and knowledge are qualified to answer questions. And from all of this, there has been a general consensus from these scientists that while they cannot specifically rule out lab origin hypothesis, there does not even begin to approximate the amount of evidence we need in order to "prove" it. Remember in science we are trying to make claims that are by nature testable- if you cannot test a hypothesis, it's then just pure speculation.
If you want to waste your mental effort on "doing your own research" and making baseless speculation, fine, waste your time. Go off the deep end and find amusement of the sort of baseless conspiracy theory folks that appear on Joe Rogan. But do not for a moment bring baseless speculation into the realm of science. Too many people have spent too much time to waste it on people who cannot intellectually appreciate the differences between testable scientific hypothesis and a baseless speculative claim.
I don't know who you think is asserting that lab origin is "proven"? The claim is that sufficient evidence exists that it should be investigated, not that investigation of all other possibilities should stop.
For a specific example, the WIV had a database of viral genomes, available on the public Internet. There was also a private, password-protected section. That entire database went offline in September 2019, and hasn't come back. The WIV has cited "hacking attempts" as the reason.
Do you find that reason credible? Do you believe that the contents of that database should be obtained and publicly disclosed, for open scientific review? If yes, then you share your desired policy action with the "baseless conspiracy folks". If no, then you share it with the CCP.
And since you say "priors": knowing that a pandemic emerged but nothing else, what's your prior that it emerged due to lab activity? I assume you're aware that the 1977 flu pandemic was probably a lab escape, and depending how you count we've had perhaps a dozen pandemics in the last fifty years; so I don't see how you can claim less than ~5%. That's far from negligible, so what evidence takes you from there to dismissing it as "baseless speculation"? It can't be the novelty of the pathogen, since a distinctive part of the WIV's research was specifically their collection of novel pathogens from nature (about 900 miles away, to be clear; Wuhan wasn't in an expected natural spillover zone).
Ralph Baric invented modern coronavirology. He was Zhengli Shi's mentor, and published frequently with her in the past. He signed Jesse Bloom's and Alina Chan's letter in Science calling for further investigation of the origins of SARS-CoV-2:
https://science.sciencemag.org/content/372/6543/694.1
As to the specific tweet that you've linked, David Baltimore seems to disagree:
> “When I first saw the furin cleavage site in the viral sequence, with its arginine codons, I said to my wife it was the smoking gun for the origin of the virus,” said David Baltimore, an eminent virologist and former president of CalTech.
https://thebulletin.org/2021/05/the-origin-of-covid-did-peop...
My own impression is that the FCS points only weakly towards lab origin (and other evidence, like the origin city, lack of intermediate host, and pre-adaptation to humans is much more significant), but I'm not the one with the Nobel prize. But my point is that if you choose experts by almost any metric other than Twitter follower count, you'll see a very different picture.