Possibly unknowable.

The Cave’s Passage And The Limits Of Science

The passage where the bones were found is still dark.

It is still cold.

It is still roughly a thousand feet from the nearest daylight.

The mud that coats its walls and floor has not dried.

The ceiling still presses down in the places where it was always close.

The narrowest restrictions are just as narrow as they were when the ancient man squeezed through them, carrying his torch, moving deeper into the mountain for reasons that will never be fully recovered.