Here is a great, properly scaled, image of a 70,000 year old engraving fashioned by a human living at the Blombos cave at the Southern tip of what is now South Africa. Note how fine this geometric pattern is - the product of manipulative skill and fine motor control essentially identical with that of any modern engraver, calligrapher, typographer, watchmaker, artist or scientific instrument maker.
As Friedrich Engels noted over 100 years ago, and based on the scantiest of archeological evidence;
"the decisive step was taken: the hand became free and could henceforth attain ever greater dexterity and skill, and the greater flexibility thus acquired was inherited and increased from generation to generation."
Friedrich Engels. The Part Played by Labour in the Transition from Ape to Man. Die Neue Zeit. 1895.
And Engels was essentially correct;
“One cannot emphasise enough the importance of finger-thumb opposition for the emergence of man from a relatively undistinguished primate background. Through natural selection, it promoted the adoption of the upright posture and bipedal walking, tool-using and tool-making which, in turn, led to enlargement of the brain through a positive feed-back mechanism. In this sense it was probably the single most crucial adaptation in man’s evolutionary history”
Hands, John Napier, 1980, p.68
