When the triumphant hominid wins the water hole he heaves the bone into the air and it is transformed into a space satellite.
A million years of tool making from bone implement to spaceflight suggests where our energies should be focused. I believe in O'Neills Frontier thesis and believe that this is where Bush would focus our efforts!
The first tool was a bone which helped to feed the tribe and win the water hole! I.E. WAR!
Immediately after coming in contact with the alien monolith, which apparently gave the alpha male hominid in that particular tribe a jolly good idea. .....and Kubrick let the audience know the exact moment of his realization merely by playing the opening bars of Zarathustra.