MEXICO: Context is everything. Find evidence of cacao beans in an ancient Maya drinking vessel, it is pretty clearly some kind of chocolate beverage. But find that same evidence on a plate, and it’s time to start thinking about mole sauce. The recent finding of theobromine and caffeine compounds characteristic of chocolate on a Maya plate dating to between 600 and 500 b.c. suggests that, in addition to being imbibed, cacao was also used as a condiment or sauce. —Samir S. Patel