this is maybe not a natural virus. >> dr. christian anderson is an evolutionary biologist at the scripps research institute. in late january 2020, he wrote to dr. fauci in correspondence that was also later released. >> we are concerned about this particular virus. we think that what we are looking at here might be different than what we would expect to see just from a naturally-emerged virus. >> anderson and other scientists worked around the clock, searching for clues deep in the genome. >> the engineering aspect of this very quickly we realized we just don't have the evidence to support that. >> even though they initially thought this novel virus had evidence of bioengineering, they subsequently found evidence of similar traits in other known naturally occurring viruses. >> we debated up one side and down the other and ultimately decided, if you were a human trying to design a really