Cheating in the Viral World

The extent to which cheating occurs in the natural world has proved contentious. We suggest that viruses offer an exceptional opportunity for studying cheats, individuals that exploit the cooperative behaviour of others. In particular, we show that: (1) cheating is common in viruses; (2) there are many different types of viral cheat; (3) viral cheats offer novel problems for social evolution theory; (4) viruses offer excellent empirical opportunities for studying cheating; (5) cheating shows that viral populations experience substantial conflict, changing how we think about how viral infections evolve; (6) evolutionary theory about cheating could help us understand viral evolution; (7) a greater understanding of cheating in viruses could aid viral intervention strategies.