Why can creatures such as salamanders and insects regenerate an entire limb?

Question

What is regeneration? Why can man only regenerate skin, nails, our second set of teeth and repair bone fractures, muscle and skin injuries and some kinds of nerves when salamanders and insects regenerate limbs?

Answer 1

Lizards / salamanders can regenerate it because they were MEANT to regenerate it.

if Nature had made em so that their tails don't come off they would be easy to catch by the tail. The tail is necessary though so it regrows. Though the regenerated part will never be as good as the original and may even hurt it or cause undesired affects. people don't really have any predators since were at the top of the food chain so our limbs have no real reason for this functionality. Also since an animal can only regenerate using cartilage this would not work. The human body has to be supported by bone NOT cartilage. I hope I answered your question....