How come ,for instance,
we don't have like some monkeys with a mouth that ended up on the side of their head type of thing?
Well, first off, if you think of it, heads are pretty round. We set up our definitions of 'front,' 'side,' and 'back' based on where features are. Wherever on the head we have ears, we make it the side. Wherever there is a mouth, we make it the front. Wherever there is nothing but hair, we make it the back. If there
were cM
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aK
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nists running around with mouths on the 'side' of the head, we would probably just see the side as being the front and consider them normal
.
However! There is the fact that monkeys with funky mouths would have a hard time surviving. The ridiculous shape and contortion of their inner workings would be so messed up, they might not even make it past child years. Which, is the idea of evolution... the ones who can't make it die; all who can live and pass on their genetic information. Besides, mouth position has been around a LOT longer than primates, and with no selective pressure to dramatically alter such things, well, they probably had fun just sticking around
.
Jonicus