Revamping the Evolutionary Theories of Aging.

Revamping the Evolutionary Theories of Aging.
Ageing Res Rev. 2019 Aug 23;:100947
Authors: Johnson AA, Shokhirev MN, Shoshitaishvili B
Abstract
Radical lifespan disparities exist in the animal kingdom. While the ocean quahog can survive for half a millennium, the mayfly survives for less than 48 hours. The evolutionary theories of aging seek to explain why such stark longevity differences exist and why a deleterious process like aging evolved. The classical mutation accumulation, antagonistic pleiotropy, and disposable soma theories predict that increased extrinsic mortality should select for the evolution of shorter lifespans and vice versa. Most experimental and comparative field studies conform to this prediction. Indeed, animals with extreme longevity (e.g., Greenland shark, bowhead whale, giant tortoise, vestimentiferan tubeworms) typically experience minimal predation. However, data from guppies, nematodes, and computational models show that increased extrinsic mortality can sometimes lead to longer evolved lifespans. The existence of theoretically immortal animals that experience extrinsic mortality - like planarian flatworms, panther worms, and hydra - further challenges classical assumptions. Octopuses pose another puzzle by exhibiting short lifespans and an uncanny intelligence, the latter of which is often associated with longevity and reduced extrinsic mortality. The evolutionary response to extrinsic mortality is likel...

Source: Ageing Research Reviews - August 22, 2019 Category: Genetics & Stem Cells Authors: Johnson AA, Shokhirev MN, Shoshitaishvili B Tags: Ageing Res Rev Source Type: research