The road to regeneration starts here:

“By academic standards, shifting from cardiology to developmental biology is a bizarre career move. Regeneration studies is a backwater even among biologists, who have been chopping the legs off salamanders for more than 200 years without ever discovering why some of them manage to grow back. And while clues to regeneration have emerged – retinoic acid will induce some frogs to grow three new legs in place of one – the field has a history of derailing respectable scientists.

As to whether humans could ever develop similar capacities of self-repair, most biologists have concluded, albeit reluctantly, that the answer is no. There seems to be something inherently different about amphibian cells: a swamp-animal mutability that mammals – including people – simply don’t possess.

But Keating remains convinced that newts hold the key to human healing. Our bodies, he points out, can already regenerate to a degree, repairing broken bones and regularly trading dead cells for new ones. Skin cells, for instance, last about two weeks, and our stomach lining molts once a month. This constant replenishment is what enables our 70-year lifespan, but cell growth is calibrated to run at a trickle: too slow to fix major damage. Lose an arm or a kidney and that’s it; we can’t generate the lost part any more than a car can sprout a new transmission.

Why? It’s an evolutionary mystery. The ability to regrow legs and eyes seems like a clear Darwinian advantage – one that surviving generations would have retained. But a paradox of regeneration is that the higher you move up the evolutionary chain, the less likely you’ll have the ability to regrow limbs or organs. Keating’s mission: figure out the cause of this paradox – and reverse it.” —Wired