Chemical traces of arecoline in the dental tissue.

Rounded grooves worn deep into the enamel by years or decades of holding a hard seed in the mouth.

This is what the oldest evidence for human drug use looks like.

It does not look like a dramatic moment.

It does not look like anything, really, without the analytical tools that turned the grooves and the chemical traces into a story.

The story is: a person, living and foraging in the tropical karst of South Sulawesi between 16,000 and 25,000 years ago, had a habit.