Why do some salamanders regenerate lost limbs?

After an injury, many salamanders form a blastema, a mass of cells that behaves a bit like early embryonic tissue and rebuilds the missing structure. Researchers have studied this process in axolotls and newts, which can regenerate not only limbs but also parts of the tail, spinal cord, and even eye tissues. The genetic switches involved help cells dedifferentiate and then organize into bone, muscle, nerves, and skin. Most mammals cannot do this because their healing process favors scarring instead of full regrowth. Salamander regeneration remains a major focus in regenerative medicine research.