rationalskepticism.org

Sendraks wrote:

Jayjay4547 wrote: The ostrich is a bipedal adept sprinter. Its high-mass muscles are at the top of its legs, with relatively thin, long lower legs. Quadruped antelope prey species that are good sprinters embody the same logic of lowered inertia in the lower limbs. Modern man, who has inherited the gross features of australopiths, is known to be a poor sprinter,

Homo sapiens is a poor sprinter compared to other mammals, but outrivals most species as a persistance hunter.
Sprinting aside, given that against an ambush like predator such as a leopard, sticks and stones are going to achieve very little, you have to wonder if australopiths were so adept at selecting and using weapons as tools (of which there is no evidence for), why didn't this trait persist into later generations of hominids? Why were homo sapiens in africa living off a largely vegetarian diet which they supplemented with meat gathered from persistance hunting?

Jayjay4547 wrote:Glad to hear we can outsprint an elephant and a mamba. Seems we can also outsprint a squirrel, chicken, house mouse, spider, three-tailed sloth and garden snail.

With the exception of a few species, homo sapiens is quite capable of running them until they drop and invariably die of overheating. Homo sapiens didn't use weapons to use hunt meat in africa (the use of weapons and complex hunting strategies was very much the domain of neanderthal man), they used a hunting strategy ideally suited to certain key features of human biology.

Supposing for the sake of argument that Australopiths were persistence hunters, exhausting their prey that invariably died from overheating, that would only make the hominins more vulnerable to predation themselves. As they ran they would open up new unfamiliar vistas, coming now and then upon sabretooth, leopard, hyena and lion who could simply run them down because unlike alternative prey, they could not sprint fast. You are conflating two quite different issues. You are offering an explanation for how the Australopiths got things to eat, as if it also explained how they avoided being eaten. It’s muddle-headed and not because you are, but because of stupid group think. None of your rational, skeptical confreres have pointed out this problem in your argument. Indeed your line of argument has been used before.

Your argumwent has another problem: Immediately after you supposed that persistence hunting would magically give hominins immunity from being hunted themselves, you then visualize one actually being hunted by an ambush predator, against which yiou say, sticks and stones would be little use. Now you inconsistently confront the fact that a felid predator rushes up at unmatchable speed, jumps on the prey and bites. Yes, and you need some way to stop it from doing that.

You say that sticks and stones would be little use against a leopard. Well in the first place, that obliges you to scout around for some other anti-predation strategy that the hominins appear to have been adapted into. I have suggested that there is no sign of either sprinting or tree-climbing adaptations. Descendants of Australopiths certainly do use sticks in the form of knobkerries and spears and are adept at that. So then one needs to look critically at whether hand-held unworked stones and sharpened sticks could be effective against predation. That’s where my little observation is relevant; that a stick held defensively can stop an attack, take the initiative away from the attacker and make it vulnerable. I called that Surveyor’s theory, it could equally have been Postman’s theory. Here’s a selfie I took some time ago:

Does the dog look a bit box-like to you? I thought so too. When you have a stick in your hand a quadruped doesn’t look so impressive. Apart from being cognitively challenged; what to do with this close threat, while keeping alert to what the hominin might do with its other arm.

Another sign of muddle in your argument is when you ask, why were the australopiths largely vegetarian? Well that’s the point. There are certain found objects (I called them “ems” in the pic, to avoid unjustified assumptions that would go with calling them “tools”) that are useful in defense against predation but irrelevant in hunting. A modern example of such a “stopper” is a shield. But originally a sharpish stick would serve. The australopiths must have been extremely proficient defenders long before their descendants developed the sophisticated tools needed for hunting big game.