It would seem that we haven't quite pin pointed when homo sapiens developed precision use with thumb and forefinger...meaning, they can put pressure there. Our neighbors the chimpanzees cannot manage this. Anthropologists have tied it to tool use or climbing trees or both. Tool use appears way before homo sapiens wander on the scene, so its hard to say when it was.
The bone adjusts quickly to new uses...you can see this in archers... so the transition may have been very rapid.