Scientists have cloned a vintage virus. Still works! The article contains a nice explanation of why this is a safe thing to do:
“There's a theoretical risk of this, and we know that the nucleic acid of the virus was in great shape in our sample,” study author Eric Delwart of the University of California told New Scientist. “But old viruses could only re-emerge if they have significant advantages over the countless perfect viruses we have at present.”
I wonder if this is the conventional wisdom among biologists. I think I understand the argument. Delwart is saying that the viruses we have today are extremely well adapted to our environment, and a randomly selected virus from 700 years ago is correspondingly unlikely to have any particular advantage over them.
On the other hand, the same argument says that invasive species should never have an advantage over native ones, right?
And just generally, I think of natural selection as a greedy algorithm, which means it finds local maxima and gets stuck there. Randomly going back and thawing out 700-year-old viruses seems like simulated annealing—in other words it’s exactly what a computer scientist would do on purpose to help their evolutionary algorithms get unstuck!
All of which is just idle speculation coming from me. I should emphasize that it would be nuts to take a 43-word quote in a short blog post as fully characterizing anyone’s view on the subject. Presumably this has all been discussed to death by people who actually know something about it. I wonder where I can read more.