Human ancestors got access to fire at least one million years ago. And with it it is trivial to cook starchy roots by baking in ashes. As for the need for agri

Human ancestors got access to fire at least one million years ago. And with it it is trivial to cook starchy roots by baking in ashes. As for the need for agriculture consider that single modern day hunter gatherer in Amazon forest can within few hours get enough starchy vegetables in a forest to feed at least 10 persons.