This African Poison Has Been Used for 60K Years

The oldest known poisoned weapon was 7,000 years old—until a recent analysis on arrow tips in South Africa pushed the date back more than 50,000 years. The analysis of the stone tips previously excavated from the Umhlatuzana Rock Shelter in KwaZulu-Natal has turned up chemical traces of plant toxins dating back roughly 60,000 years, according to a study published Wednesday in Science Advances. Researchers reexamined 10 quartz arrow tips from a cache of hundreds unearthed in 1985 and tied to the Howiesons Poort culture, dating to about 65,000 to 60,000 years ago, per Live Science. Five of the points carried residues of buphandrine, and one also held epibuphanisine—both plant-derived toxins.

The most likely source, the team says, is Boophone disticha, or "poison bulb," a tumbleweed relative that currently grows within 10 miles of the rock shelter. It's still used today as arrow poison in southern Africa. The toxins work slowly, weakening animals and making long pursuit hunts less grueling. Small amounts would be lethal to rodents within half an hour, CNN reports. Lead author Sven Isaksson of Stockholm University says the work shows early hunter-gatherers weren't just harvesting plants but deliberately tapping their biochemical punch. Because the poison doesn't kill instantly, hunters would have had to understand delayed cause and effect and plan accordingly, the study notes—evidence of sophisticated cognition.

Archaeologist Justin Bradfield, who wasn't involved in the research, calls the discovery "remarkable" and notes that the Umhlatuzana hunters seem to have used a single-ingredient poison, with more elaborate mixtures potentially emerging later. The study also demonstrates that such chemical traces can survive for tens of millennia, raising the possibility that other ancient tools may still hold invisible evidence of early humans' chemical know-how. Researchers, who found the same toxins on four 250-year-old arrowheads collected in South Africa, now hope to test younger layers at the shelter to see whether the poison-arrow tradition endured or vanished and was later reinvented.