Negligible Senescence

What it means

Negligibly senescent species show:

• No statistically significant increase in mortality rate with age.
• No measurable decline in reproductive output.
• No characteristic aging diseases (most don’t develop cancer at predictable rates).
• Often continuous growth through life.

This does not mean immortal — they still die from predation, disease, or environment. But the Gompertz curve is flat or close to it.

Known examples

• Hydra (freshwater cnidarian): essentially no senescence.
• Several rockfish species — some recorded >200 years old.
• American lobster: continued growth and telomerase activity.
• Bowhead whale: oldest recorded >200 years; cancer-resistant proteome.
• Galapagos tortoise: very low age-specific mortality.
• Naked mole-rat: not perfectly negligible but extraordinary flatness of the Gompertz curve.

What it implies

The existence of negligibly senescent species shows aging is not a universal biological inevitability — specific mechanisms can hold it off. Identifying those mechanisms is part of the comparative-biology research programme at Rochester, Calico, and elsewhere.

What it doesn’t imply

• That humans can achieve negligible senescence with current biology.
• That the mechanisms easily translate (some are tissue-specific, like continued telomerase activity that would raise human cancer risk).

Related entries

Vera Gorbunova & Andrei Seluanov, Telomerase, Gompertz law, Calico.