In a windowless underground computer lab in California, young men are busy cooking up viruses, spam and other plagues of the computer age.

When the mapping of the human genome was completed in 2003, researchers discovered a shocking fact: our bodies are littered with the shards of retroviruses, fragments...

Tracing the origins of viruses is difficult because they don’t leave fossils and because of the tricks they use to make copies of themselves within the cells...