The knowledge your brother has accrued is still knowledge. He just needs to change the filter he's using, to work out what it all means. Get him to do that. Ask him: "Let's assume viruses are simply leftover RNA that is not capable of carrying disease or spreading between hosts. Reorder what you know to support this theory. Then knock hole in it."
The knowledge your brother has accrued is still knowledge. He just needs to change the filter he's using, to work out what it all means. Get him to do that. Ask him: "Let's assume viruses are simply leftover RNA that is not capable of carrying disease or spreading between hosts. Reorder what you know to support this theory. Then knock hole in it."
Because that is not what happens.
Spreading between hosts — though we learn more about this process, is still a concretely proven reality.