Other species evolved clever ways to protect themselves from
catching illness long before we developed treatments. What do they do?
Humans are constantly at war with disease. We lob antibiotic
missiles at bacteria and toss vaccine-shaped grenades at viruses. We drop bombs
made of antibacterial soap and hand sanitiser on everything we can. The battle
between humans and parasites (an umbrella term that includes viruses, bacteria
and much larger creatures that thrive on a host) has ancient roots, and exert
as strong a force on evolution as predators, drought or famine.