The last post on endurance running/persistence hunting as an important human adaptation generated a lot of interest, so I thought I'd give an update. The new issue of Journal of Human Evolution has some commentaries between the authors of that paper and some critics of the idea.
The evolution of endurance running and the tyranny of ethnography: A reply to Pickering and Bunn (2007)
The endurance running hypothesis and hunting and scavenging in savanna-woodlands Travis Rayne Pickering, and Henry T. Bunn
In a nutshell, the critics cite paleo-environment evidence that Homo was in a denser savannah woodland enivronment two million years ago, that would not have been suitable for running long distances due to excessive vegetation and compact ground (as opposed to sand that would tire prey out). They also discuss the lack of any evidence for ER among Hadza and other groups, and the plausibility of sophisticated tracking abilities needed for ER hunting that far back (2mya). I'd have to say that I am pretty skeptical myself of the ER running hypothesis as a significant human adaptation. However I am not familiar enough with the physiological and anatomical evidence that supporters of this idea present.