Immortality in Nature Explained

Organisms including Greenland sharks, hydras, giant tortoises, and bristlecone pines exhibit negligible senescence—aging chronologically without biological deterioration.

Hydras achieve biological immortality through infinite cellular self-renewal driven by FoxO transcription factors, with all animals possessing FoxO genes affecting lifespan.

Leonard Hayflick discovered in 1961 that human cells can only divide approximately 50 times before ceasing replication, contradicting earlier claims of cellular immortality by Alexis Carrel.

Lobsters express telomerase enzyme allowing infinite cell replication and hypothetical immortality, while humans restrict telomerase to prevent cancer—cells refusing to die and continuously replicating.

Turritopsis dohrnii, the immortal jellyfish, achieves negative senescence—the only organism capable of reversing biological aging and returning to juvenile states.