| Frailty in nature | Animals that are elderly and frail are observed in nature, not just in the lab | Naive selection shadow theory: natural selection is blind to late-life frailty alleles and doesn’t get a chance to purge them |
| Gompertz law | | |
| CTVT | A dog transmissible cancer cell line (CTVT) has persisted for 10,000+ years | Naive intracellular accumulation/depletion models: all cells become worse over organismal lifespan because evolution couldn’t find a way to preserve a good substance or cleanse a bad substance |
| Immortal germline | Zygote-germline-zygote cycle has persisted unbroken for 1 billion+ years | Naive intracellular accumulation/depletion models. |
| Peto’s paradox | | |
| Serial cloning | In a mouse line maintained exclusively by cloning, birth rates began to decline from the 27th generation, and the 58th generation was the last | |
| Common traits of long-living species | Species known for long lifespans tend to be: 1. Low predation risk 2. Eusocial 3. Intelligent. 4. Large 5. K-strategists | |
| Social insect longevity dimorphism | In social insects, queens and workers share the same genome, yet queens (who reproduce) live 10-30x times longer than workers (who don’t reproduce) | Naive disposable soma theory: in all species, reproduction is in a resource trade-off with longevity |
| Avian and bat longevity | Birds and bats feature active metabolism, higher body temperatures than rodents of comparable mass, and yet live many times longer than rodents. | Naive “rate of living” theories: species that run their internals faster also wear out faster. |
| End-of-life somatic mutation burden | In intestinal crypts among 16 mammalian species, the end-of-life mutation count per cell was very similar (around 3k mutations per lifespan) despite large variations in body mass and lifespan | |
| Octopus lifespan | Despite being decently large and very intelligent, all species of octopus live under 5 years. | |
| Antioxidant unresponsiveness | Overexpression of antioxidant enzymes fails to extend mammalian lifespan | Free radical theory of aging |
| Caloric restriction longevity | Many lifespan records in many species were set under caloric restriction conditions | Naive disposable soma theory |
| Dwarf longevity | Within the same species (mice, dogs), dwarf strains tend to live longer | |
| Heterochronic parabiosis | | |