COVID originsNatural Origin or Genetic Manipulation? We “Can't Say for Sure Yet”: David Baltimore
David Baltimore, president emeritus of Caltech and Distinguished Professor of Biology, is a virologist who received the Nobel Prize for his research into viral genetics. He says that “But the fact that evolution might have been able to generate SARS-CoV-2 doesn’t mean that that’s how it came about. I think we very much need to find out what was happening in the Wuhan Institute of Virology. I think that we can’t say for sure yet whether the SARS-CoV-2 virus came from natural origins or if it was genetically manipulated somehow.”
The search for the biological origins of SARS-CoV-2, the virus that has caused the COVID-19 pandemic, is continuing. Similar viruses before it have been shown to have jumped from animals to humans; yet this link has not yet been definitively found for SARS-CoV-2.
Caltech’s David Baltimore, president emeritus and Distinguished Professor of Biology, is a virologist who received the Nobel Prize for his research into viral genetics. Baltimore was an organizer of the first Asilomar Conference on Recombinant DNA held in 1975 to discuss ethics and regulation of biotechnology.
Caltech News sat down with Baltimore to discuss the debate over the origins of SARS-CoV-2.
Caltech News: What are the arguments that suggest SARS-CoV-2 is a naturally evolved virus? What is the evidence that suggests that it may have originated in and accidentally released from a laboratory in Wuhan, China?
David Baltimore: The argument that it’s a naturally evolved virus is from the belief that through the time of evolution, any sequence of RNA or DNA could evolve.
Biologists have seen what evolution can create: the whole natural world around us. We believe that evolution can do anything. But the fact that evolution might have been able to generate SARS-CoV-2 doesn’t mean that that’s how it came about. I think we very much need to find out what was happening in the Wuhan Institute of Virology. I think that we can’t say for sure yet whether the SARS-CoV-2 virus came from natural origins or if it was genetically manipulated somehow.
CN: Recently you were quoted as saying: “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. These features make a powerful challenge to the idea of a natural origin for SARS2.” Can you unpack this quote for us?
Baltimore: Let me be clear, even though I used the phrase “smoking gun,” I don’t really think there’s a smoking gun in the genome itself.
Now, within the SARS-CoV-2 genome there is an insertion of 12 nucleotides that is entirely foreign to the beta-coronavirus class of virus that SARS-CoV-2 is in. There are many other viruses in this class, including the closest relative of SARS-CoV-2 by sequence, and none of them have this sequence. The sequence is called the furin cleavage site.
