Most modern human infectious diseases were unknown before domestication led to a mass spillover of animal disease into human populations.6 For example, tuberculosis appears to have been originally acquired through the domestication of goats7 but now infects nearly one-third of humanity.8 Meanwhile, measles9 and smallpox10 may have arisen from mutant cattle viruses. We domesticated pigs and got whooping cough, we domesticated chickens and got typhoid fever, and we domesticated ducks and got influenza.11 Leprosy may have come from water buffalo and the cold virus from horses.
