Scientists study salamanders and their ability to regenerate lost legs and tails. What additional information is essential for scientists to understand in order to apply this ability to humans who have lost limbs?

According to Charles Darwin's Theory of Origin of Species, an organism either develops or losses an attribute according to its adaptation to survive in a competitive environment. This is same with humans or salamanders. The loss or the retention of limbs may indicate the survival purposes of the species.

Human regeneration is generally limited to single types of tissues. Salamanders can regrow multiple types of tissue to make complete structures like limbs. We need to understand regeneration by finding the genes involved.