Humans may one day have the ability to regrow limbs after scientists at Harvard University uncovered the DNA switch that controls genes for whole-body regeneration.

Some animals can achieve extraordinary feats of repair, such as salamanders which grow back legs, or geckos which can shed their tails to escape predators and then form new ones in just two months.

Planarian worms, jellyfish, and sea anemones go even further, actually regenerating their entire bodies after being cut in half.