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The evolution of aging is a fascinating topic: why do we age, and why do we age the way we do? Why are some species near-immortal, so far as we can measure, while others come and go in the blink of an eye? How is it that we live far longer than many of our nearest relatives in the animal kingdom, but nowhere near as long as we'd like? You'll find a number of posts on that topic back in the archives:
And so forth. The latest batch of SAGE Crossroads podcasts looks at the evolution of aging. I think you'll find them interesting.
#51 - Evolution of Aging - What are the prominent theories of how we age?
Daniel Perry discusses a few of the major theories of aging. He also tells us why it's important to understand these theories and how they impact aging research.
#52 - Evolution of Aging - Accounting for aging across species
KYLE JENSEN: Now do you know why the species, the aging in species, is vastly different?
STEVEN AUSTAD: No, that’s ultimately the question we hope to answer because if you look at the natural world the difference in aging between the shortest lived and longest lived species is vastly greater than that we can create in the laboratory. So, we feel like nature is providing us with good examples and all we need to do is figure out the key mechanisms that differ between the short and the long lived species.
#53 - Evolution of Aging - What is the developmental drift theory?
The idea of developmental drift is that a developmental pathway that’s used to make healthy tissue in normal animals is not maintained in old age. In our case, there is a developmental pathway that has three regulators, L5 - L6 - L3, whose normal job is to make particular tissues in the young worm in the intestine, and these three regulators are no longer maintained in the old worm, and so one of the developmental regulators turns down and two turn up in old age, and these become unbalanced.
When these become unbalanced, the transcription factors become unbalanced and they cause myriad downstream changes in gene expression that are detrimental to the worm. All of this happens in old animals, that is after the force of natural selection has gone away. Everything we’re talking about are things that happen to the homeostatic processes when nature no longer cares about homeostasis.
These are, I should emphasize, representative viewpoints from the mainstream of aging research - wherein scientists believe that altering metabolism to slow aging is the only viable path forward.
Posted by Reason at October 1, 2008 7:59 PM
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