Anthropological Evidence of Distance Running

Here's a summary of some anthropological research I've heard talked about that might be of interested to runners:

http://www.sciencedaily.com/releases/2004/11/041123163757.htm

What do you think? Have we evolved to be long distance runners?

All I know is that I can take Casey, the border collie, in a 10 mile run, but he has me easily at short distances.