Posted: Dec 10, 2019 5:48 am
by Spearthrower
JJ... stop for a moment. Stop trying to score some points and use your brain.

I wrote this earlier - you of course ignored it.

Imagine the grip you'd need for:

squeezing a small seed to pop its kernel
holding a needle to push it through against resistance
poking a twig into a hole
using a knife to cut through leather
holding out a stone the size of your hand
smashing a bowling ball down onto the ground
throwing or thrusting a javelin

Right there, sitting in your armchair, act these out. If you were holding a needle and pushing it through, say, a piece of animal hide... how would you shape your hand. What muscles would you be using? Now try another one. Note that your hand shape is different, that the muscles you're using are different ones.

Thus there can be no gross simplification of 'grip' - you can't just say, oh chimpanzees can grip a tree, therefore they can wield a hammer because that's beyond simplification - it's a kind of semantic argument that essentializes a word to its most simple level without acknowledging the massive variation contained therein.

Thus my summary to that point:

These are just a few grips with very different anatomical uses, and while humans can do all of them, other primates can be better, worse, or incapable of doing them.

This is relevant to this thread and claims made herein in many ways, but it is of course mostly relevant to how afarensis may have been able to manipulate objects and calls back to many rebuttals I've made about JJ's insistence on afarensis doing X or Y when they lack the anatomy used in the modern human hand to perform that kind of grip.

I'm not arguing against afarensis wielding spears because I don't want it to be true... I am arguing against it because it just cannot be true due to anatomical limitations. You can call it a smokescreen all you like - it's really just cognitive bias to protect yourself from an idea you can't defeat with reason - I know anatomy, you don't know anatomy... learn something JJ - it costs you nothing.