Evolution of Longevity as a Species-Specific Trait in Mammals

Abstract

From the evolutionary point of view, the priority problem for an individual is not longevity, but adaptation to the environment associated with the need for survival, food supply, and reproduction. We see two main vectors in the evolution of mammals. One is a short lifespan and numerous offspring ensuring reproductive success (r-strategy). The other one is development of valuable skills in order compete successfully (K-strategy). Species with the K-strategy should develop and enhance specific systems (anti-aging programs) aimed at increasing the reliability and adaptability, including lifespan. These systems are signaling cascades that provide cell repair and antioxidant defense. Hence, any arbitrarily selected long-living species should be characterized by manifestation to a different extent of the longevity-favoring traits (e.g., body size, brain development, sociality, activity of body repair and antioxidant defense systems, resistance to xenobiotics and tumor formation, presence of neotenic traits). Hereafter, we will call a set of such traits as the gerontological success of a species. Longevity is not equivalent to the evolutionary or reproductive success. This difference between these phenomena reaches its peak in mammals due to the development of endothermy and cephalization associated with the cerebral cortex expansion, which leads to the upregulated production of oxidative radicals by the mitochondria (and, consequently, accelerated aging), increase in the number of non-dividing differentiated cells, accumulation of the age-related damage in these cells, and development of neurodegenerative diseases. The article presents mathematical indicators used to assess the predisposition to longevity in different species (including the standard mortality rate and basal metabolic rate, as well as their derivatives). The properties of the evolution of mammals (including the differences between modern mammals and their ancestral forms) are also discussed.

Platypus longevity: a new record in the wild and information on captive life span

“…By definition, long-lived mammals are subject to relatively low mortality risk as adults. Positive associations between species-specific longevity and a low metabolic rate or adaptations to survive hypoxia have also been posited, possibly because these attributes select for biochemical features that also tend to protect animals against disease and ageing (Omotoso et al 2021;Shilovsky et al 2022). Both attributes plausibly apply to the platypus (Ornithorhynchus anatinus), which can remain submerged for at least 11 min (Evans et al 1994) and expends metabolic energy at around half the rate of amphibious eutherian mammals of similar size (Grant and Dawson 1978;Bethge et al 2001).…”