Portside

Small errors incorporated into the genome when a pathogen copies itself offer clues to reconstruct chains of transmission and learn about epidemic dynamics along the way.

Until recently, [some] specimens have been un-sequenceable due to DNA contamination from the modern people who have handled them. Today’s techniques make it possible to differentiate modern from ancient DNA sequences, which opens up the prospect of returning to the many museum specimens in collections worldwide to see what further answers they might hold.