Vegetarian Thread

[BeardofPants]

Originally posted by Amandil
However, I don't see how anything you said, BoP, challenges significantly what I said. Assuming that my "common ancestor of various other hominids" corresponds to the australopithecenes, my main claim regarding them was that their jaws and teeth were too heavy to allow for speech. But I'm not clear (yet, I'm sure you'll help me, BoP) that australopithecenes are a common ancestor of various other hominids. If they co-existed with homo erectus, I would think that at best the aussies were the ancestor of just the erectiles (and us, via erectus), but not any other hominids (or did all the other ones die out a long time before, but australopithecene survived on?).

At any rate, even if the heaviness of the australopithecene mantible and dentition was not due to eating raw meat, had they so desired the heaviness of their mantibles and dentition would have quite readily facilitated raw meat-ing (although a few canines would have come in handy, too). But my point still remains: the heaviness of their mandibles and dentition would not have facilitated "speech," any more than a lion's mouth does. Of course, I wasn't clear that my use of the word "speech" referred to our sort of verbal (and facially expressive) communication as opposed to grunting like a pig, or barking like a dog, which also qualifies as "some form of verbal communication." I'd expect that all sorts of animals, australopithecenes and people included, have some sort of verbal communication. Just that heavy mandibles and dentition like the australopithecenes' (which may have evolved due to milling grains in one's own mouth, but are also well suited for chawing down on raw animal flesh--more so than our own, at least!) are not well suited for the quality and nuance of homo sapiens' form of communication.

I'm not quite sure what you're asking here exactly. Homo erectus co-existed with some species of Australopithecines, ie the ones that were dead ends in the evolutionary development. And I agree with you that australopithecines probably didn't have complex verbal communication. However, I don't think this was due to the robusticity of their jaws. Endocasts of australopithecine skulls clearly show that their Brock's & Wernicke's areas were not developed enough for the capacity of speech. Furthermore, their larynx had not dropped low enough. But, here I have to mention, that IF these were all completely adapted for speech in our ealier ancestors, then they probably would not have been restricted due to heavy eating apparatus. The size of their malar and zygomatic processes suggest that they were extremely heavily muscled in their faces, and therefore, would have been very very strong. Obviously, they would have to have been, because of their dietary adaption; if they can eat extremely hard nuts and grains (look at the size of their teeth!), then I don't think verbal communication would have been a problem. No, it was due to ill-developed speech mechanisms, rather than their size. (And this sort of ties back into the big brains, small guts hypothesis... speech probably came about indirectly due to that increase in meat intake.)

Regarding erectus, it is contentious, because they DID have significant development in their Brock's & Wernicke's regions, BUT up until recently it was thought that the larynx and pharynx of erectus probably hadn't dropped low enough to enable speech. But then that guy that claimed that neanders didn't have the dropped larynx was pretty much debunked fairly recently because his diagrams failed to take into consideration the different shape of the neander skull as compared to sapiens, ie lower and flatter, and more elongated horizontally, and this has also been applied to erectus, who also didn't have the vertically elongated skull that sapiens has. However, spinal evidence of erectus suggests that speech - as in symbolism and complexity - was probably not likely. (The idea being that more complex species have larger spinal cords, and erectus' was still the size of an ape.)