Taboos Are For Coordination

Archaeologists use one simple trick to track the spread of Islam in Southeast Asia.

It’s difficult because unlike other mass conversions, Southeast Asia’s conversion to Islam came at the tip of trade, instead of a sword.

So what do people use to tell when a community converted to Islam?

The jawbones of pigs.

Austronesians loved eating pigs. Muslims don’t eat pigs. There weren’t many Jews in Southeast Asia. Therefore, if there were pig jawbones in the trash heap, that community probably wasn’t Muslim.