Scientists Regenerate Wing In Chick Embryo

Contrary to most animals when you cut off a salamander's leg a brand new one will sprout. Now a research team at the Salk Institute for Biological Studies has been able to regenerate a wing in a chick embryo, suggesting that the potential for such regeneration exists in all vertebrates; including humans. Studies have demonstrated that vertebrate regeneration is controled by a powerful Wnt signaling system whose activation results in regeneration in animals that can't normally replace missing limbs while inactivating it in animals known to be able to regenerate their limbs (frogs, zebrafish, and salamanders) shuts down their ability to replace missing legs and tails. Manipulating Wnt signaling in humans is not possible at this point, but there are hopes that these findings may eventually offer insights into examining the ability of stem cells to build new human body tissues and parts.
This is truly amazing! Imaging losing an arm and just being able to grow back another one! Science has taken the first step and it is no longer impossible!

http://www.sciencedaily.com/releases/2006/11/061119114814.htm