Did death evolve?

[David George]

well the immortality gene cannot be recitified according to me because those genes are as such cannot be made to work what I am saying is there is only chances for giving potential immortality for lower species and immortality will make a species vulnerable due to wear and tear.

[mkwaje]

This topic really has me thinking. A lot of concepts have been brought forward too. Before we can answer the question of whether death has evolved or not, we have to make sure that the our concept of death are similar. Some say that DNA is the basic unit of life and since DNA continue to exist in our progenies albeit in altered/modified form; then there is really no true death; so we are just really the extension of "life" starting from that primordial soup where life came from. If we see individual cells as the unit of life, then would cell division be some kind of death? If for example, we have a sperm cell and then it combined with an egg cell, can we say that there were 2 individuals that died to bear oone complete organism. Will our fertilized egg cell die over and over again in the process of differentiation to form an embryo? Lastly, we can probably agree that our concept of death is not in the individual cells but in the complete human being, as a baby to an aging human for example. Now if we are to compare death of a bacteria or a slime mold and us, then death would be have to be a different concept for each of them.

My two cents is this: that all life from the tiniest single celled organism to the most complex multicellular organism (imo, a woman) are in constant battle with entropy. Death is simply the manifestation of that losing battle. But I do not view death as the end of life but a stage in life; so if you say that death has evolved... I would say that death has always been there and would always be there manifesting as cell division, as aging, as cancer cells, as DNA replication errors, as mutations, as absence of nutrients, as accumulation of toxins, etc..

Another thought, if you will consider our planet as a super organism, having complex interaction of biotic and abiotic factors, involving innumerable distinctly separate individuals all working as a whole for its preservation and development, then death will take on a whole new meaning.

I belive that the meaning of life is arbitrary, that we humans believing that we are the most intelligent and advanced life form on the planet coined the term "life" associating characters to it like replication, response to stimuli, etc. That's why we have so much problem classifying viruses, prions, etc; we don't know exactly where to put them, living or non-living. In the face of this I would say that death is also a relative term; that it is a too short sighted event of life. Death is a stage in life not the end of it.

[James]

Nice post, it puzzles me whether aging, cancer, DNA errors etc are really a result of 'the battle with entropy'. They seem ideal processes to evolve in order to limit population size, which somehow could be evolutionarily beneficial. As for saying that death is a stage of life, that would support the idea that death has evolved wouldn't it?

[xand_3r]

Cancer cells have an altered cell cycle, having rapid division and lacking the mechanisms for apoptosys so we could say that they're immortal. Anyway, if an organism lives long enough, even without an ageing mechanism it will eventually die because of negative mutations. Mitochondrion DNA cannot be repaired so well since it lacks the complex repairing mechanisms of eucaryotes (like the removal of timine dimers). So mutations in that DNA occur 10 times more often. Anyway, even with the mechanisms of repair, some mutations escape repairing, which in turn will lead to a more and more altered genetic material. If these mutations occur in the gametic cells, mutations will be passed to future generations. Maybe a reason for the existance of ageing mechanisms is to avoid the spanning of a more and more altered DNA.

[Linn]

If we had no stresses, no illness, etc or anything "oxidizing" us to death, we would live much longer. there is no reason cell rejuvination should not be able to go on indefinetly.

What do ya think?

[Dustfinger]

Look. Nature has to keep itself existing, so what do you think would happen if endless hordes of bacteria, animals, human beings etc. would live on and on and reproduce ? Either the universe is endless (which we don´t know for certain) or death of these living creatures will be the natural extension of life because the universe cannot "feed" all them.

[dyna_r]

well, every cells, as the functional units of living organism precisely will die...

[geonyzl]

well, just keep in mind that one character of a living organism that has its own life span. Life span would vary in different individual in each species. Life span would also depend on the kind of environment and its life style.


geon

[Azedenkae]

BTW, er... doesn't bacteria NOT die?

Some might, but basically when the time comes they just divide into 2 daughter Bacterias?

Which is not really 'dying' but splitting into 2?

[sachin]

Hmm.. Perfect thinking "Death EVOLVED?".

I think this is great , Say from millions of years death is Natures rule.
Nature have created diff. disease, antities, chronic damages for reason of death. but Organisms seems to be adapted for those conditions as generation goes on so Reasons of death need to be evolved to keep natures rule alive.

[nugget]

This is quite an interesting thread, and the idea that cancer cells are immortal? ... well i remember seeing a picture of a cancerous tumour that was "kept alive" for like ages and it just kept getting bigger. ill have a look for that actually.

We cant be immortal, because like all things dna replication isnt perfect and death is probably a good thing or else we would be living for such a long time but with dysfunctional organs as our mutations would just accumulate!!

We can either live as invalids, or die as we enter that stage !

[Dr.Stein]

Every living thing will die..