Reuters is reporting a protein that's expressed in newts regenerating limbs. It sounds like a no-brainer that someone should look for this in octos with missing arms, to see if invertebrate regeneration is ancestral (and ancient) or convergent evolution. Anyone want to get right on this? As much as hacking the arms off octos is mean, it seems like once the protein's been IDed in one animal, it should be pretty easy to chop off an arm, wait until it starts to regrow, chop it off a little lower, and look for this protein. And the octo will then even re-grow the arm again, hopefully. Or maybe the newt scientists even have a fluorescent antibody for the protein, in which case it might be possible to just make the octo glow in the dark as its arm regrows the first time. edit: they should look at starfish, too, to see if it's a deuterostome thing.