[Last Visible Dog]

Our running ability is useful for running things down, not for getting away from things.

Then the numbers are even worse - the overwhelming sprint speed advantage of four legged mammals would mean man is not going to run down much.

[ahayes]

They sprint and widen the range rapidly, we just keep jogging after them. We can keep up a moderate pace for longer than they can continue running away. One day of work yields thousands of calories--pretty good payback for the outlay. Perhaps this will help to clarify things.

Our ability to cover a lot of ground at a steady pace is also useful for foraging as well as for hunting.

[js1138]

Then the numbers are even worse - the overwhelming sprint speed advantage of four legged mammals would mean man is not going to run down much.

You are assuming a prey animal can keep up a sprint speed over a long distance in the summer heat. They can't. A typical human jogger can kill his pet dog by overheating it.