All animals have significant changes in their bodies’ operating systems over time. Not just a slow deterioration, but some things stop working, and other things start up.

How can a mechanism controlled by short-term chemical reactions do such a thing?

Is it “hard-wired” in the brain?

Or some very slow controlling chemical reaction?

Do we have any idea?

If we do, why aren’t the pop-sci magazines full of it?

I remember seeing a documentary that telomeres might be part of that.
https://en.wikipedia.org/wiki/Telomere

I believe certain genes get “switched” on at different stages (puberty etc)

Each bodypart has a steep bell-curve MTBF?

The Rev Dodgson said:

Is it “hard-wired” in the brain?

Or some very slow controlling chemical reaction?

Do we have any idea?

Affirmative

Spiny Norman said:

I remember seeing a documentary that telomeres might be part of that.
https://en.wikipedia.org/wiki/Telomere

Gradually shortening telomeres looks like a feasible mechanism at least.

I find it surprising that this isn’t covered more in the pop-sci press (or maybe I’ve just missed it).

Dropbear said:

I believe certain genes get “switched” on at different stages (puberty etc)

But what tells them when to switch on (or off)?

The Rev Dodgson said:

Dropbear said:

I believe certain genes get “switched” on at different stages (puberty etc)

But what tells them when to switch on (or off)?

that would be related to growth regulation wouldn’t it?

Riff-in-Thyme said:

The Rev Dodgson said:

Dropbear said:

I believe certain genes get “switched” on at different stages (puberty etc)

But what tells them when to switch on (or off)?

that would be related to growth regulation wouldn’t it?

And what controls growth regulation?

(but there are many changes which are not directly related to growth anyway).

The Rev Dodgson said:

Riff-in-Thyme said:

The Rev Dodgson said:

But what tells them when to switch on (or off)?

that would be related to growth regulation wouldn’t it?

And what controls growth regulation?

(but there are many changes which are not directly related to growth anyway).

as far as developing to maturity goes, wouldn’t there be a progression of complexity of systems? when one system begins producing such and such it triggers the next system(just guessing). After maturity I thought it was a matter of maintaining DNA reproduction

Hormones play a part, but I don’t know what switches them on either.

Riff-in-Thyme said:

as far as developing to maturity goes, wouldn’t there be a progression of complexity of systems? when one system begins producing such and such it triggers the next system(just guessing). After maturity I thought it was a matter of maintaining DNA reproduction

An obvious example that does not seem to fit with this is menopause in women, but there are similar events in men and non-humans.

Telomere story and then I’ll go to bed

>>>>How can a mechanism controlled by short-term chemical reactions do such a thing?

which happens over the life time of the body

CrazyNeutrino said:

>>>>How can a mechanism controlled by short-term chemical reactions do such a thing?

which happens over the life time of the body

What happens over the life time of the body?

The Rev Dodgson said:

Riff-in-Thyme said:

as far as developing to maturity goes, wouldn’t there be a progression of complexity of systems? when one system begins producing such and such it triggers the next system(just guessing). After maturity I thought it was a matter of maintaining DNA reproduction

An obvious example that does not seem to fit with this is menopause in women, but there are similar events in men and non-humans.

is menapause the result of prolonged absorption of growth and fertility hormones in the system?

The Rev Dodgson said:

Dropbear said:

I believe certain genes get “switched” on at different stages (puberty etc)

But what tells them when to switch on (or off)?

Hormones among other things.. Released from glands. What controls that? I guess we’re back to DNA programming then.

Someone who knows a bit about biology, or Alex will be along soon

dv said:

Telomere story and then I’ll go to bed

JF used to be awesome at explaining this stuff.

The Rev Dodgson said:

All animals have significant changes in their bodies’ operating systems over time. Not just a slow deterioration, but some things stop working, and other things start up. How can a mechanism controlled by short-term chemical reactions do such a thing?

What strikes me most is that in old age everything stops working at almost the same time. Skin, bones, circulatory system, eyesight, hearing, immune system.

> How can a mechanism controlled by short-term chemical reactions do such a thing?

The simplest way to get an insight into this is to study Hutchinson-Gilford Progeria Syndrome, where symptoms similar to aging occur at a greatly advanced rate. See Progeria

> “Without lamin A, the nuclear lamina is unable to provide the nuclear envelope with adequate structural support, causing it to take on an abnormal shape. Since the support that the nuclear lamina normally provides is necessary for the organizing of chromatin during mitosis, weakening of the nuclear lamina limits the ability of the cell to divide.”

So aging is due to progressive failure of the ability of a cell to divide. The accumulation of damage to cells would have the same effect.

Science Show today (timing) -

Elizabeth Blackburn grew up in Tasmania, studied at the University of Melbourne and is now based at the University of California, San Francisco. In 2009, she became the first Australian woman to be awarded the Nobel Prize for medicine. This was for her work on telomeres, the structures found on the ends of chromosomes. They were previously considered unimportant, but Elizabeth Blackburn demonstrated the role played by telomeres, and the enzyme telomerase in a range of diseases of ageing.

——————

Blackburn talked about fitness, happiness being correlated to less telomere wear.

Those on top of the food chain in the public service live longer… those with more control.

Astoundingly enough, those who live to a great age have a greater degree of resistance to telomere wear (IIRC).

Those with high cynical hostility (bubbles might want to have a think :) – Climate change contrarians.

There seems to be something more solid stopping aging much after 120 years.

correction -

Those with high cynical hostility (bubbles might want to have a think :) ..climate change contrarians experience more telomere wear.

Those permanently tired and likely to fall over at any moment from insomnia (like myself) no doubt are in the latter category.

bump for TRD

Thanks Ian, looks interesting and relevant.

Not sure about the bubbles connection though :).