That sounds like the theory Christopher McDougall presents in Born To Run. As far as I know, he doesn't have any credentials in the relevant fields (not that that has too much impact on whether the theory is likely or not) so maybe he is relying on previous work? If you don't mind me asking, where have you gotten your information from?

EDIT: Nevermind, I followed your link to persistence hunting and from there to Endurance Running Hypothesis.