Biological weapons are, quite simply, ancient history. The most persuasive proof is contained in the unthinking words that spill from your own lips: The noun "toxin" is derived from the ancient Greek term for arrow poison. Tracing the evolution of bioweapons from ancient times to today, one simple truth emerges. Throughout time, humans have harnessed whatever knowledge of destruction they possessed to benefit themselves and protect against enemies.

Click "View Slideshow" to see the range of biological weapons humans have used throughout history.