Way off topic:- persistence hunting and endurance running

jimmypippa

I found this quite interesting, and I suspect many cyclists are also interested in physiology/sport science etc, especially seeing some of the posts by DonDaddyD... Also I find it interesting in relation to my own observations that a limiting factor for me on my commute seems to be heating. Changing to a lightweight (cloversport) top, my home journey was quicker (5-mins) and more comfortable.

Professor Daniel E. Lieberman is an anthropologist at Harvard, and argues (plausibly to me) that human endurance running ability evolved because it helped with "persistence hunting" (chasing an animal until it drops). (homepage here)

Lieberman points out that whilst humans can't run as fast as a zebra, for example can gallop, nor walk as fast as one, humans can run faster than a zebra can trot. He also states that humans can sweat, so are less prone to hyperthermia than (say zebras), we can sweat whilst running, but they need to slow to a trot to cool down by panting.

Endurance running and the evolution of Homo, NATURE |VOL 432 | 18 NOVEMBER 2004 (PDF)

A more extreme comparison of performance that is not adjusted for body size is between humans and large mammals such as ponies and horses (Fig. 2a). Human ER speeds exceed the preferred trotting (3.1m/s) and the trot–gallop transition (4.4m/s) speeds of ponies (110–170 kg), and even the preferred trotting speed predicted for a 500-kg quadruped.

(For comparison the document quotes endurance running speeds of 6.5m/s for elite athletes and 3.2-4.2 m/s for recreational joggers).

The role of forcing prey animals above their trot-gallop transition sped is made is made more clear in this later paper...

The evolution of endurance running and the tyranny of ethnography: A reply to Pickering and Bunn (2007), Journal of Human Evolution 53 (2007) 434e437 (PDF):
(ESA is Early Stone Age, ER is Endurance Running, PH is persistence hunting)

Pickering and Bunn (2007) do not explain how ESA hominids could have hunted without ER and projectile weapons other than to provide an ethnographic account that demonstrates that hominids could have walked during pursuit hunts. But walking alone does not accord well with the physiological evidence. It may be possible in extreme heat to outwalk a small ungulate such as duiker, but the point of PH is to keep an animal
above its trot-gallop transition speed for long enough to cause it to develop hyperthermia (and not, as Pickering and Bunn suggest, to tire it). Running is necessary because most mammals can dissipate heat adequately via panting when walking or trotting but not when galloping. Galloping mammals cannot pant (Bramble and Jenkins, 1993; Entin et al., 1999). In contrast, mammals can walk or trot incredibly long distances at speeds
that are faster than optimal human walking speeds, even in hot conditions (Dill et al., 1933). It is thus doubtful that humans could regularly drive large mammals to hyperthermia by walking. In fact, if such a strategy were possible, then it would surely be more common (why run if one could walk?).

Here, quotes Liberman

All together, Lieberman said, these adaptations allowed us to relentlessly pursue game in the hottest part of the day when most animals rest. Lieberman said humans likely practiced persistence hunting, chasing a game animal during the heat of the day, making it run faster than it could maintain, tracking and flushing it if it tried to rest, and repeating the process until the animal literally overheated and collapsed.

Most animals would develop hyperthermia — heat stroke in humans — after about 10 to 15 kilometers, he said.

I was wondering if this was a bit too far off topic, but decided it probably wasn't...