A HUMAN REGROWTH INDUSTRY? The ability to regenerate body parts has always been a fascinating prospect, inspiring characters like Wolverine who can instantly heal themselves and regrow body parts they've lost — and now regeneration has inspired scientific research. Many species in the animal kingdom can regenerate: arthropods (like scorpions) can regrow appendages, some annelids (like worms) can regenerate from only a few segments of their body, echinoderms (like starfish) can both self-amputate and re-grow limbs, amphibians (like salamanders and newts) can regenerate a limb in as little as a month, and some reptiles can regenerate their tails. The aquatic acorn worm, a small coral reef dweller that burrows in the sand and one of the closest invertebrate relations to the human, can regenerate any part of its body that has been cut off, even its nervous system and head. Cutting an acorn worm in half simply results in two complete, indistinguishable specimens within fifteen days.