If evolution really gave a shit, we'd shed teeth like sharks, though.
Actually, not just sharks do it, most non-mammals with teeth do. Sharks are more famous for it because they also have row upon row of teeth!. Mammals are specifically evolved not to do this.
Because nothing but mammals have complex, multipurpose teeth the way we do, and they're supposed to mesh very tightly. The only you've got a chance to get them to fit together like that is to have a very specific planned growth sequence. If they grew in whenever, they'd all be different sizes.
The meshing in turn is because our metabolism run so high, we need very efficient eating. The planned (and delayed) growth of teeth, in turn, is probably the reason milk evolved.
I could go on for a while about my theoretical frameworks this all fits into, but I've already just gone on for a while :p
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Actually, not just sharks do it, most non-mammals with teeth do. Sharks are more famous for it because they also have row upon row of teeth!. Mammals are specifically evolved not to do this.
Because nothing but mammals have complex, multipurpose teeth the way we do, and they're supposed to mesh very tightly. The only you've got a chance to get them to fit together like that is to have a very specific planned growth sequence. If they grew in whenever, they'd all be different sizes.
The meshing in turn is because our metabolism run so high, we need very efficient eating. The planned (and delayed) growth of teeth, in turn, is probably the reason milk evolved.
I could go on for a while about my theoretical frameworks this all fits into, but I've already just gone on for a while :p
p.s. I got no ideas on the pain, though.