I've previously read and heard about what great long distance runners humans are, we may not be the strongest or fastest or have the most poisonous bite, but besides our big brains, this was/is one of our 'things' that gave us an edge.
I've also heard that one of the reasons for our proficiency at this is that we have amongst the best control of our breathing in the animal kingdom (on land at least I think) as well as the way our skeletons and muscles are etc.
I've just started reading "The ancestors tale" by Richard Dawkins, and when he was writing about when our ancestors may have started to speak he mentions one fossil (Turkana Boy) that the "portholes" in the vertebrae are too small, suggesting he didn't have the fine control over breathing associated with speech.
This got me thinking, could the very fact that we were physiologically predisposed to be good at long distance running have been a driving factor in our evolotion of fine control over breathing and hence have contributed to our development of speech and the growth of our brains?
Tell me if this is a dumb idea!