Long before Thanos snapped his fingers in Avengers: Infinity War, another villain successfully killed half of humanity.

Malaria is a simple parasite, transmitted by a mosquito bite. But this deadly disease, which has been around as long as homo sapiens, has killed more than all wars and natural disasters combined. It has wiped out cities, destroyed empires, ruined colonies, and may be responsible for 50 billion deaths, among them Alexander the Great and Marcus Aurelius (allegedly).

Malaria's role in history is perhaps more under-appreciated than anything else. Here's two examples: Many historians believe America won the Revolutionary War due to malaria depleting the ranks of infected soldiers. Some think it caused Rome's downfall.

When the malaria parasite was discovered in the 1800s it led to containment efforts. But the real game changer was the deployment of DDT in World War Two. Deadly swamp lands (like much of the United States) were now safe for human habitation. Even South Pacific islands were no longer death traps.

However, the fight against malaria took a different turn in the 1960s with the publication of Silent Spring, a book that argued pesticides could permanently damage earth's ecological balance.

Malaria is not the killer it once was but it still plays a massive role in public affairs debates today.

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