[Baeocystin]

Human tribes in the rainforest have levels of social sophistication, technology, and manipulation of their local environment that outstrips any other animal. It's not close.

Look at the recent discoveries in the Amazon basin. Layers of dirt thousands of years old, still filled with the charcoal used to improve soil quality. Species of plants that were clearly selected for over time. The list goes on.

https://en.wikipedia.org/wiki/Terra_preta