Comment by syrrim on Why We Age, Part 1: What ageing is and is not · 2020-05-24T23:55:14.913Z · LW · GW

If you lost a bone, you lost the whole limb. It seems like a repair system should be able to grow a limb from scratch, seeing as that's how limbs come about in the first place.

Part two is already up on his blog.