Storyline:

2001 is a story of evolution. Sometime in the distant past someone or something nudged evolution by placing a monolith here on earth (presumably elsewhere throughout the universe as well) Evolution then enabled man to reach the moon's surface where he finds yet another monolith, one which signals the monolith-placers that we have evolved that far. Now a race begins between computers (HAL) and man (Bowman) to reach the monolith-placers, the winner will achieve the next step in evolution, whatever that may be.