Lose your arm? No problem, we'll grow it back for you!

Although reptiles and amphibians sit lower on the evolutionary tree than humans do, they have something that we don't. The ability to regenerate lost limbs. When they lose a limb, special cells are activated and new cell growth is stimulated. The lost limb, whether it be leg or tail, grows back good as new, except in a few incidents where something may go wrong. Such examples are two tails instead of one. But now a group of Harvard researchers are trying to do the same thing except with humans.

The Harvard researchers admit that humans and reptiles are extremely different. However they hope to use the reptiles as a model and by learning how reptiles regenerate, they can learn if it is possible for humans to as well. Cliff Tabin, one of the main researchers, says, "... Figure out what's the same and what's different about regeneration mechanisms." So although studying amphibians and reptiles might not lead to the gold at the end of the rainbow, it could definitely guide them to another rainbow that may have the prize at the end. Regeneration is more complicated than it looks sounds though. Regenerating a limb requires recreation of muscle and bone, then hooking it back up to the body, and making of nerve cells that connect perfectly up with original existing ones. This study goes close in hand with stem cell research, a still controversial study.

War has ravaged this country and may veterans come home with missing limbs. Some have lost their arm, some have lost their entire lower body. If this research proves successful , those men and women could regain what they had to leave behind on the battlefield. The uses aren't limited to wounds of war either. People who have lost limbs through industrial accidents could also regain their body parts. It may seem like mechanical and prostetic arms maybe the only solution for now, but one day, people may just be able to have their real arm back.

National Geographic Volume 218, Number 3. 2010