I'm not saying otherwise! I'm saying that the formulation has little sense either way. Compare: 'there is little observed variation in anatomy between apes in broad sense because the evolutionary pressure constraining anatomical changes is too great to allow much viable variation', 'there is little observed variation in anatomy ..., but not in intelligence, because further evolution of intelligence allows for greater success and so younger branches are more intelligent and better at survival', 'only change in anatomy drives change in intelligence, so apparently there was some great hack which translated small changes in anatomy to lead to great changes in intelligence', 'chimpanzees never tell us about the voices they hear'...
There are million of years invested into the task about how to move with legs. There's not millions of years invested into the task of how brains best deal with language.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.