has mammal-like mutation rates facilitating fast adaptation despite its nonaging phenotype.

Growing evidence suggests that somatic mutations may be a major cause of the aging process. However, it remains to be tested whether the predictions of the theory also apply to species with longer life spans than humans. is a genus of freshwater polyps with remarkable regeneration abilities and a potentially unlimited life span under laboratory conditions.

Population density shapes patterns of survival and reproduction in (Hydrozoa: Anthoathecata).

Budding hydromedusae have high reproductive rates due to asexual reproduction and can occur in high population densities along the coasts, specifically in tidal pools. In laboratory experiments, we investigated the effects of population density on the survival and reproductive strategies of a single clone of . We found that sexual reproduction occurs with the highest rate at medium population densities.

Worker lifespan is an adaptive trait during colony establishment in the long-lived ant Lasius niger.

Eusociality has been recognized as a strong driver of lifespan evolution. While queens show extraordinary lifespans of 20years and more, worker lifespan is short and variable. A recent comparative study found that in eusocial species with larger average colony sizes the disparities in the lifespans of the queen and the worker are also greater, which suggests that lifespan might be an evolved trait.

Constant mortality and fertility over age in Hydra.

Senescence, the increase in mortality and decline in fertility with age after maturity, was thought to be inevitable for all multicellular species capable of repeated breeding. Recent theoretical advances and compilations of data suggest that mortality and fertility trajectories can go up or down, or remain constant with age, but the data are scanty and problematic. Here, we present compelling evidence for constant age-specific death and reproduction rates in Hydra, a basal metazoan, in a set of experiments comprising more than 3.

Age-related cellular changes in the long-lived bivalve A. islandica.

One of the biggest challenges to studying causes and effects of aging is identifying changes in cells that are related to senescence instead of simply the passing of chronological time. We investigated two populations of the longest living non-colonial metazoan, Arctica islandica, with lifespans that differed sixfolds. Of four investigated parameters (nucleic acid oxidation, protein oxidation, lipid oxidation, and protein instability), only nucleic acid oxidation increased with age and correlated with relative lifespan.