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Did death evolve?

Discussion of the distribution and abundance of living organisms and how these properties are affected by interactions between the organisms and their environment

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Did death evolve?

Postby James » Wed Apr 06, 2005 12:54 am

Could it be possible that death has evolved? The very first organisms, however they came about, may not have had death; however as time progressed, populations that were immortal grew so large that competition was extreme, and eventually led to these organisms not having the environment to be able to reproduce. As this was happening, another population, which had earlier had a mutation to limit their lifespan was progressing well, with competition never enough to halt the organisms not being able to reproduce. Thus, the population that had limited life span actually had a favourable position and then went on to evolve, spread and go on, whilst the population of immortal organisms could not evolve, and eventually died out by extraneous variables. Could it be possible the first organisms were immortal, and that death is evolutionary beneficial?
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Postby biostudent84 » Wed Apr 06, 2005 1:10 am

At the moment, I disagree...but if you can defend it against debate, I could probably be convinced.

I've stated them before, but I'll say it here as well to set the record.

The two biological laws: Why we live.
1. Survive to an age where you can reproduce
2. Reproduce successfully*

*reproducing successfully stipulates that at least one of an organism's offspring also fufills the two laws. R-selected organisms like flies do this by having thousands of offspring. K-selected organisms like humans do this by living a long time, helping to raise our children and our children's children.

Hmm. Two statements and a disclaimer and I'm already wavering. Anyone else have any thoughts?
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Postby 2810712 » Thu Apr 07, 2005 7:40 am

Good q.
Bacts have death, viruses do , fungi probably don't have it. So, there is no uniformity .
I think, it really didn't occur the way u have stated.
One more IMP point
See the early organisms were just envolope of biomolecules with meatabolism occuring inside. So, they reproduced by deviding , so they had death.

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Postby mith » Thu Apr 07, 2005 8:23 pm

Do you mean ageing death or death in general? Because bacteria don't need to evolve the ability to die, a few cups of molten lava would kill them.

I don't think your theory holds(assuming you're talking about death through ageing)....

Let's assume that indeed the first organisms were immortal. They would reproduce and evolve through successive generations. When the population reaches carrying capacity, the ones that were not as adapted would die out, not from age but from starvation or possibly be eaten.
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Postby James » Fri Apr 08, 2005 12:23 am

Yeh, I guess immortal orgainisms would be unlikely to die out unless there was another particular disadvantage that came along with being immortal. The whole idea seems a bit silly,as from a genes view, with immortality there would be no need to reproduce, as the genes carried by an organism wouldn't need to be passed onto a new generation as they would be around forever anyway. O well :|
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Postby 2810712 » Fri Apr 08, 2005 11:16 am

Yeah, death due to ageing has evolved, probably.
But , how can we say that early lifeforms were immortal ???

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Postby mith » Fri Apr 08, 2005 8:37 pm

Immortality would mean it is immune to ageing.

1st you have to understand the nature of ageing...is this something the cell wants? Or is it an inevitable decline in the condition of its genetic material(incomplete copying, random mutations etc)?
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Postby 2810712 » Sat Apr 09, 2005 10:24 am

How can we call immortality means ageing-immunity ? ? ?
I've understood , probably, ur concept , it seems to be correct, and thus ageing did evolve but we can't say that death evolved , it was just an imporatant result of that .

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Postby mith » Mon Apr 11, 2005 9:22 pm

Well not ageing is included in the defintion of immortality which probably would include invulnerability but I don't think that was what james meant.
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Postby GreenDog » Mon Apr 18, 2005 4:03 pm

It looks like a very interesting idea, and it might be possible. Bacteria for example, the simplest organisms, do not die of "old age", though they do age, have many mechanisms of programmed death. It seems like there is no reason for bacteria co commit suicide when they can live forever, but in fact persistent mutants (defective in PCD mechanisms), die very fast. Persistent populations have many disadvantages to usual bacteria. The ability to die serves an important role in the bacterial population.
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Postby biostudent84 » Mon Apr 18, 2005 7:34 pm

One of the smartest professors I ever had (Dr. Charles Blem) once taught that while not all organisms have it in their genes for programmed death, most do. Humans have their own programming to die...it's called cancer.

"No matter how healthy you keep your body, if you live long enough, you will get cancer."

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Postby mith » Mon Apr 18, 2005 8:34 pm

Isn't a cancer cell an immortal cell?
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