OK, I'll have to rely upon what I read in pop sci articles pro or con about changes of opinion etc. Meantime I was thinking (yes, I think, I think I think) what "mutations" would make a gorilla-type (an ape that walks on all fours) find it better to walk upright and then have such a superior brain capacity -- if you understand the question. The theory is that these tree hanging swinging apes evolved to humans. OK, ok, not gorillas because for some reason no one knows what the "Unknown Common Ancestor" supposedly was -- but I wonder if scientists actually propose it was not upright walking apes like humans are. What do you think? The question is if humans evolved from apes (OK, an "Unknown Commoin Ancestor), do they think (imagine) that the UCA walked on all fours rather than upright like humans do?