[0x002A]

Tribes, harvesting aren't those sound more like possible with modern social structures? I expect them to form in the latter part of the 1.5 million years period. In the graph from the tweet shows delicacy(!) was elephant around 1 million years ago.

[voakbasda]

Monkeys can be said to live in "tribes", and "harvesting" was just my polite euphemism for "bloody slaughter".