Re: Digital Genetics and Evolution Theory

Bioteach wrote:
Tim Tyler <seemysig@xxxxxxxxxxxxxx> wrote in
Bioteach wrote:

There are also organisms possessing biological suicide mechanisms
that clearly are not accumulative (e.g. bamboo, octopus).

Can you be more specific? There are plenty of causes of
death that are not cumulative - but they need not be
suicidal.

Bamboo evidently reproduce by essentially cloning, like grass.
Occasionally they flower and seed. When they flower, they die. Death
is programmed to accompany blooming and clearly not a maintenance issue.
Programmed death is apparently to prevent cloning from dominating sexual
reproduction.

In many organisms, vegetative reproduction takes place
when the going is good - and sexual reproduction takes
place when it is not - since the stress may show that the
existing phenotype is not working, and it's time to try
something new.

So maybe it's not sex that causes suicide, but stress that
leads to both death and sexual reproduction.

Also, sex may be a great reproductive effort, which
diverts resources away from maintenance programs to
operate, leading to malfunction and death.

Is there any real evidence that bamboos commit suicide?

Octopi females stop eating after reproduction and die of self
starvation. Some Polish biologist whose name I do not remember
determined that surgically removing the eyes eliminates this behavior.
No obvious way to make this into a maintenance issue.

Octopus females don't eat in order to care for their eggs.

Isn't eating a type of maintenance? The octopi are
trading bodily maintenance in favour of reproduction.

Salmon die of old age after mating.

Sex may be a great reproductive effort, which
diverts resources away from maintenance programs
to operate, leading to subsequent malfunction and death.

I think there are bigger problems with the maintenance theories:

If an organism can build itself from essentially nothing, how come
repair is such a problem? Replacing a cell shouldn't be very much
different from growing it in the first place. Many cells, (skin, blood)
are replaced often.

Nature can do regeneration if it tries. The problem is an
economic one, it makes better economic sense to make new
organisms than trying to repair existing ones. In fact,
it's the same with cars, computers, practically any complex
object - after a while it is cheaper to buy a new one than
to try and fix up the old one.

Why do things like exercise and other forms of stress seem to extend
life span if maintenance is the issue? This seems the opposite of what
one would expect.

In those cases where stress appears to extend lifespan, it
seems to work by diverting resources away from reproduction
and into maintenance and repair programs.

The classic case is calorie restriction:

http://cr.timtyler.org/why/

Exercise is a bit different, but that is the basic answer.

Those who do not believe in group selection think that the individual
benefits of sexual reproduction (e.g. pathogen resistance) outweigh the
seemingly major individual disadvantages allowing the major complexities
of sexual reproduction to evolve. Those who do believe in group
selection think that the major group benefits (essentially enabling the
evolution process in complex organisms) outweigh the individual
disadvantages. There is no way that either side can prove their case to
the satisfaction of the other.

AFAICT, neither side is wrong. It's an issue of how much
each theory explains. I'm confident biologists will get to
the bottom of the issue.
--
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|im |yler http://timtyler.org/ tim@xxxxxxxxxxx Remove lock to reply.

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Relevant Pages

  • Re: A "Perfect" World
    ... to death and decay as individuals. ... Did god kiss all booboos, ... Reproduction was limited by the environmental capacity. ... Failing to eat from this tree or source of information ...
    (talk.origins)
  • Re: The ultimate cause of aging
    ... There is a resource conflict between maintenance and reproduction, ... So evolution starves maintenance mechanisms and puts its resources ...
    (talk.origins)
  • Re: Man cannot accept wife having fun...killed her...a tragedy.
    ... > until her death, ... Except where an order for maintenance is expressed to ... > upon the remarriage of the wife; ... > or upon the remarriage of the wife ...
    (soc.culture.singapore)
  • Re: Out-dated theory
    ... surviving (in a difficult environment, ... If you take death ... in a world of very finite size reproduction without ... are a lot of dead species, ...
    (uk.religion.christian)
  • Re: Out-dated theory
    ... new does not require the death of the old. ... The way evolution works is that reproduction introduces ... Ken doesn't believe in "heavenly existence" but in a renewed ...
    (uk.religion.christian)