The old age question, revisited

[zenoandthetortoise]

"There (Their) cellular/molecular mechanisms do not cascade to senesce before an actuarially cause of death occurs."

Congdon suggests that as Blanding's reproductive capability/capacity increases with age, that other life history traits are also not the norm. That norm being reproductive senescence followed by age senescence. Most vertebrates experience actuarial death or reproductive senescence followed by age senescence. Mechanism known or unknown, it is a reasonable assertion that based on similarity in some life history traits (bigger and more eggs with size and age in some chelonians) that those same chelonians die an actuarial death before a senesce death.

That is literally what biological immortality means, death by stochastic event before death by age degeneration. If an average adult tortoise has a 1:100 chance of dying due to predation, poor retreat choice, lighting strike, whatever, in any one year, then a single cohort of 100 individuals will have one that lives to the age of 100, plus years to reach adulthood. In some cases there will be individuals that live even much longer. In some cases it will be a 1:200 ratio, those are population dependent ratios.

Captive tortoises are not in a 'normal' population. But captives are the individuals whose age can best be guessed, as people have recorded their individual life. Congdon's study (published over several venues) is one of the best for long term wild animals. The assertion that wild tortoises die due to an actuarial cause before age degeneration is reasonable.

Condon seems to play both sides. On the one, observing a lack of reproductive senescence, in contrast to the vertebrate model, but then concluding , absent that, the remainder of the pattern still applies and supports his assertions.
Regardless of inverted reproductive potential (which is fascinating in and of itself) it does not address the actual question of lifespan.
Age degeneration is the ultimate stochastic event; accumulated insult to DNA by mutation, oxidative stressors, replication errors, etc. being chief among them.
Regeneration from or resistance to these would constitute biological immortality.

 

[mike taylor]

So back to the question .... do people die from old age? I say yes they do . Say you die at 90 right because you get sick . Your immune system is weak because of age . The coroner puts cause of death the flu or kidney failure . Because it's not professional to say .... sorry your 90 year old mother died because she is old . But the truth of the matter is she did die because her age weakened her immune system .

 

[zenoandthetortoise]

Every living creature has its "shelf life"...then factor in the daily events that either increase or decrease the bottom line...lets not forget about the soul of a living creature (each has their own idea of what the word "soul" represents), the will to live as well as the will to not.....oh, and there is no scientific report that I have ever seen that proves or disproves this belief 100% without waiver....there are a lot of theories, but no PROOF.

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You have it backwards. If you wish to assert the existence of something invisible, unmeasurable and undefined (like 'soul' or perhaps unicorns) the burden of proof is yours. A statement (such as your first paragraph) without evidence can be dismissed without evidence. And so it is.

 

[Anyfoot]

Well i've learnt enough on this topic.

What are the time differences from UK to USA and across USA. I believe Illinois is 6hrs behind UK. So is California -8hrs and New York is -4hrs.

 

[smarch]

I think the biggest problem in ever being able to come up with a definite answer is the sheer age it would take to truly find out. There would need to be tons of experiments over essentially centuries to find out, and the fact that our knowledge of proper husbandry still continues to grow plays a factor too.
I did learn a lot from this thread though, especially cells only getting so many times to reproduce.... and I was a biology fan in high school.

 

[seiff]

What about old age vs natural causes?