17. Immortal Jellyfish (Turritopsis dohrnii)
The immortal jellyfish, Turritopsis dohrnii, exhibits a remarkable ability to revert to its juvenile polyp stage after reaching maturity, effectively resetting its life cycle. This process, known as transdifferentiation, involves the transformation of specialized adult cells into undifferentiated cells, which then develop into a new polyp colony. This unique regenerative capability allows the jellyfish to potentially bypass death from aging, highlighting a level of biological resilience far beyond human capabilities. For more details, see National Geographic.