Update: PDF of the paper: https://rejuvenomicslab.com/wp-content/uploads/2022/01/expger02_evolution_aging.pdf
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The authors also found little evidence of aging in multiple chelonian species, in some salamanders and in the tuatara. Protective adaptations and life history strategies – like bony shells and a relatively slow pace of life, in the case of turtles – help to explain the negligible aging in these long-lived species. In another study, Rita da Silva and colleagues examined mortality rate changes with age in captive animals, focusing on 52 turtle, terrapin, and tortoise species in zoo populations. Similarly, da Silva et al. found that senescence was slow or negligible in roughly 75% of the species evaluated. Moreover, roughly 80% experienced aging rates lower than that of modern humans. Unlike humans and other species, the findings in controlled settings also suggest that some turtle and tortoise species may reduce physical aging in response to better environmental conditions, in which – as conditions improve – they can allocate more energy to survival rather than protection, thereby extending their lifespans.
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Warning: Experimental rant
From this paper linked above, it may look like aging is an evolutionary strategy for the underdog (NOT saying here that this is the demonstration of the paper’s author): mammals could not compete with dinosaurs, so they evolved to age rapidly and so to live and change more intensely, and thus to adapt more rapidly and efficiently as a species.
But as the species comes to dominate, aging capabilities come back. For example, the first elephants were smaller, as most mammals, but have since then, as they became dominant in their biotope, develop up to six sets of molars, which is clearly a sign of better longevity (elephants need their molars to eat and thus to survive).
Now, evolution seems to be excruciatingly slow for a short-lived species such as ours. And I would argue that it is “natural” that humans proceed to accelerate it using their unique cerebral capacities. In this sense, doing intensive scientific research openly targeting longevity, even in orders of magnitude, fits very well with evolution itself.
I find this idea somehow comforting 
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