First, a clarification: whether SARS-CoV-2 was laboratory-constructed or manipulated is a separate question from whether it escaped from a lab. The main reason a lab would be working with SARS-like coronavirus is to test drugs against it in preparation for a possible future outbreak from a zoonotic source; those experiments would involve culturing it, but not manipulating it.
But also: If it had been the subject of gain-of-function research, this probably wouldn’t be detectable. The example I’m most familiar with, the controversial 2012 US A/H5N1 gain of function study, used a method which would not have left any genetic evidence of manipulation.
First, a clarification: whether SARS-CoV-2 was laboratory-constructed or manipulated is a separate question from whether it escaped from a lab. The main reason a lab would be working with SARS-like coronavirus is to test drugs against it in preparation for a possible future outbreak from a zoonotic source; those experiments would involve culturing it, but not manipulating it.
But also: If it had been the subject of gain-of-function research, this probably wouldn’t be detectable. The example I’m most familiar with, the controversial 2012 US A/H5N1 gain of function study, used a method which would not have left any genetic evidence of manipulation.