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.
Now scientists have discovered that that in worms, a section of non-coding or 'junk' DNA controls the activation of a 'master control gene' called early growth response (EGR) which acts like a power switch, turning regeneration on or off.
"We were able to decrease the activity of this gene and we found that if you don't have EGR, nothing happens," said Dr Mansi Srivastava, Assistant Professor of Organismic and Evolutionary Biology at Harvard University.
"The animals just can't regenerate. All those downstream genes won't turn on, so the other switches don't work, and the whole house goes dark, basically."
The studies were done in three-banded panther worms. Scientists found that during regeneration the tightly-packed DNA in their cells, starts to unfold, allowing new areas to activate.