Why We Fall Apart

DM_NeoFLeX writes "An article in the September 2004 IEEE spectrum raises some interesting ideas comparing aging in organic organisms to aging in Electronic/Electrical systems. From the article: "The [reliability theory] is so general it can be applied to understanding aging in living organisms...In the ways that we age and die, we are not so different from the machines we build.""

Mirror of article.

[tod_miller]

According to the article the fountain of use is temporarily unavailable.

shucks.

I'll post the article for anyone else having problems with the site:

Service Unavailable

The server is temporarily unable to service your request. Please try again later.

Cryptic, i'll give you that, but I expect they will find out the question to the answer soon enough.

The general idea is...

[Cyclone66]

that human aging can be modeled according to reliability theory that applies for machinery. The difference is, while machines start off 'perfect' (You don't buy a multi cpu system with 2 cpus dead on arrival) the human body 'ships' as a redundant system with many failures already in place.

Imperfect electronics

[bill_mcgonigle]

You don't buy a multi cpu system with 2 cpus dead on arrival

I suspect IBM's eFuse [theregister.co.uk] is at least partially a way to improve yields. If we don't need 'perfect' electronics they might get cheaper. Linux can work around [vanrein.org] bad RAM chips, too.

The article in case of slashdotting

[ASayre8]

Engineering's reliability theory explains human aging

By Leonid Gavrilov & Natalia Gavrilova

CHILDHOOD IS A SPECIAL TIME INDEED. If only we could maintain our body functions as they are at age 10, we could expect to live about 5000 years on average. Unfortunately, from age 11 on, it's all downhill!

The problem is that our bodies deteriorate with age. For most of our lives, the risk of death is increasing exponentially, doubling every eight years. So, why do we fall apart, and what can we do about it?

Ma

Actually that would be "how" we fall apart

[hey!]

Why we fall apart is simple.

Sex.

If we reproduced by mitosis, we'd be effectively immortal, even better, we'd get up to 2^n chances to survive in the nth generation of offspring.

Given our specific method of sexual reproduction, you have basically one life to live. Anything that breaks down, any bad mutations (cancer), and that's it. Plus, you have to die to make room for your offspring, which I guess happens with protists and such bacteria as reproduce mainly asexually, but the offspring who you are making room for are arguably you.

Re:Actually that would be "how" we fall apart

[barawn]

If we reproduced by mitosis, we'd be effectively immortal, even better, we'd get up to 2^n chances to survive in the nth generation of offspring.

Um. No.

Identical twins reproduce by mitosis - once. The twins do not live the longer of their lifespans (nor do they get "two chances to live"). Their DNA does, but the longevity of their DNA is not the longevity of the organism.

but the offspring who you are making room for are arguably you.

Only in the twisted sci-fi worlds where a clone becomes you, with your memories, and everything else. In the real world, DNA does not define an organism. It doesn't even define how to build an organism. To paraphrase Alpha Centauri, "What we can do with genes is chemistry, because genes code for chemicals."

Sexual reproduction doesn't help nor hinder the longevity of an organism. It does reduce the genetic diversity of a population, making the population less responsive to changes. Hence the reason that sexual reproduction evolved at all.

Re:Actually that would be "how" we fall apart

[Bahumat]

Er, no, Sexual reproduction enhances the genetic diversity of a population, thus making the population less affected by changes.

Re:Actually that would be "how" we fall apart

[barawn]

Yah, yah, that was a typo.

Re:Actually that would be "how" we fall apart

[Eccles]

Sexual reproduction doesn't help nor hinder the longevity of an organism.

You mean asexual reproduction.

You have it backwards...

[hung_himself]

Actually sex evolved because of one inherent problem in mitosis - accumulated errors. Any individual cell that relies on duplicating its genome each generation also duplicates mutations which eventually accumulate. The odds of another spontaneous mutation correcting the error is virtually nil. However, the odds of two cells having exactly the same errors is also very low. Thus cells that are able to cut and paste from each others genome (have sex) are able to repair themselves and have a selective advantage

Re:Actually that would be "how" we fall apart

[CTalkobt]

>> Why we fall apart is simple.

>> Sex.

Geesh, it's go blind or fall apart.

Great. The wife's gonna love this ....

But can the theory be applied?

[waterbear]

A general theory of ageing can sound good, but can it be applied?

If it could, then the first place where even a partial application should show some effects and some value would be in medicine.

I don't see any signs of applicability there, and it looks as if there is a good reason for that. As the article admits, biological bodies are made up of a vast number of bits and pieces all doing their specific thing. When each goes wrong it produces effects which can only be countered, if at all, by doing something specific to engage with the bit that has gone wrong.

General theory may not be able to provide any general help when there appears to be no general problem, only a lot of specific ones.

-wb-

SCIAM

[bhima]

Scientific American had a most excelent article on this years ago, it's still there...if you subscribe.

Why this article is flawed somewhat.

[Anonymous Coward]

The article brings up some interesting points, but it brushes with a much to large a brush. Forinstance, for many functions cells are supposed to die to get a working system, unlike where the article suggets these deaths are a symptom of preliminary failure. Which is thus not the case.

The interesting part is more how the failure rate can be predicted by a kind of standard failure rate curve, as well as noting that humans start off with flaws from the start. With large redundancy to catch errors.
However, th

Re:Why this article is flawed somewhat.

[tentimestwenty]

The interesting part is more how the failure rate can be predicted by a kind of standard failure rate curve, as well as noting that humans start off with flaws from the start. With large redundancy to catch errors.

Ah, the secret to Microsoft's longevity.

Interesting Nature articles

[Gamasta]

I'm not sure if the texts are available to everyone else (I'm reading from a university with a site-license, I think), but here are two good articles published in Nature some time ago. Why do we age? (Thomas B. L. Kirkwood, Steven N. Austad)
Abstract [nature.com] Full Text [nature.com]

Oxidants, oxidative stress and the biology of ageing (Toren Finkel, Nikki J. Holbrook)
Abstract [nature.com] Full text [nature.com]

initial defects, folic acid, brain cells, autism

[bob_jenkins]

The article says we have a lot of defective components (brain cells) from the get-go. Being extra careful in very early development (taking folic acid) can prevent a lot of those defective components (folic acid in the first month of pregnancy reduces the chance of neural tube defects).

Autism is marked excess brain cells and low blood flow in the connections between brain cells. Perhaps the excess brain cells just take up too much room, so the connections are either cramped or not there.

Evolution takes