Maybe because it could leave at some point. Not overnight, but maybe gradually after primitive language or sounds being bundled with gestures for some time. Con

Maybe because it could leave at some point. Not overnight, but maybe gradually after primitive language or sounds being bundled with gestures for some time. Considering that humanity were hunter gatherers the main topic was likely animals and the weather. I think it grew out of those campfire situations and planning huntings, map making (drawing scenarios on the ground) and then basically animating it with sounds and signs.