**Negligible Senescence in Different Organisms:**
– Some fish and tortoises exhibit negligible senescence.
– Naked mole-rats are the first mammal with negligible senescence.
– Ginkgo trees resist aging through gene expression.
– Aspen trees and Methuselah tree demonstrate biological immortality.
– Bacteria can live indefinitely at the colony level.
– Tardigrades can survive for thousands of years in cryptobiosis.
– Certain algae, plants, and animals show negative senescence.
– Turritopsis dohrnii can regress to a larval state multiple times.
**Longevity Mechanisms and Characteristics:**
– Examples of species with negligible senescence.
– Species with mechanisms to repair damage and maintain cellular function.
– Extreme longevity in species like the Greenland shark.
– Increased peroxidation resistance in mitochondrial membranes.
– Understanding longevity mechanisms for aging research.
**Biological Aging Models and Studies:**
– Planarian model system and sea anemone for studying aging processes.
– Freshwater pearlshell and Arctica islandica for testing longevity mechanisms.
– Senescence research in sea urchins and mitochondrial peroxidation resistance.
– Immortal worms providing insights into aging processes.
**Challenges to Traditional Views on Aging:**
– Gompertz–Makeham law of mortality challenged by negative senescence.
– Lizards, sea urchins, and corals exhibit negative senescence.
– Research on biological immortality and engineered negligible senescence.
– DNA damage theory of aging and maximum lifespan concepts.
– Societal effects of negligible senescence and indefinite lifespan.
**Scientific Publications and Senescence Studies:**
– Publications on planarian model system, sea urchin senescence, and freshwater pearlshell.
– Studies on longevity variations in different species and mitochondrial peroxidation resistance.
– Evolution’s mistakes offering lessons on aging processes.
Negligible senescence is a term coined by biogerontologist Caleb Finch to denote organisms that do not exhibit evidence of biological aging (senescence), such as measurable reductions in their reproductive capability, measurable functional decline, or rising death rates with age. There are many species where scientists have seen no increase in mortality after maturity. This may mean that the lifespan of the organism is so long that researchers' subjects have not yet lived up to the time when a measure of the species' longevity can be made. Turtles, for example, were once thought to lack senescence, but more extensive observations have found evidence of decreasing fitness with age.
Study of negligibly senescent animals may provide clues that lead to better understanding of the aging process and influence theories of aging. The phenomenon of negligible senescence in some animals is a traditional argument for attempting to achieve similar negligible senescence in humans by technological means.