PEOPLE DOMESTICATED sheep and cattle, wheat and maize. Wasps domesticated viruses. And, simply as domesticating different species helped human populations explode, so viral domestication assisted an explosion of wasps. That, at the least, is the conclusion of Benjamin Guinet, an evolutionary biologist at Lyon College, in France. As he writes within the Proceedings of the Royal Society, he thinks an ancestor of a bunch of wasps referred to as the Cynipoidea, which parasitise flies, corralled 18 viral genes into its genome in an act of domestication that occurred 75m years in the past, and that this helped the group flourish.