Did death evolve?

[sachin]

Good scientific and Ecological Answer Jimmy.

[mattw]

Isn't a cancer cell an immortal cell?

Isn't to say this a contradiction in terms?: The cells are "immortal" but they cause the death of their "host" organism. (Us.)

[Poison]

Isn't a cancer cell an immortal cell?

Isn't to say this a contradiction in terms?: The cells are "immortal" but they cause the death of their "host" organism. (Us.)

Cells are immortal because they do not go throught apoptosis. They cause death of the organism but they don't do it intentionally. It's just a result of the changes occured in cancer cells and their continuous division.

[AstusAleator]

immortal means they dont' die, but they do. They might not undergo apoptosis, but they CAN die.

[Poison]

how do you define the death of a cell then?

[AstusAleator]

cell death can happen many ways.
Apoptosis is simply the programmed death of a cell.

Cells can die from attacks by other cells/organisms
cells can die due to a hostile environment (lack of nutrients etc)

I'm no micro biologist, but I guess cell death could be defined as a cessation of function accompanied by destruction of the cell body.

[45561]

I was thinking there could have been a situation where reproduction was hindered due to the inability for organisms to die, thus death was favourable.

I think that it's possible. Competition between parent and offspring may harm proliferation to some extent. If the parent dies, then it is no longer competing with its offspring (the parent is already developed, probably larger and may be cannibalistic), so the offspring have a better chance of survival and can go on to reproduce more quickly.

It might be better to select against size than immortality, since there is a limit to how many organisms can survive in a space anyway, but evolution lacks foresight.

It is good to ask whether or not longevity was limited early in life's history. As suggested earlier, lava is pretty fierce. I think it more likely that the systems that allow long life conferred no advantage, and so if they did develop they were not selected for (rather than selected against), and so senescence was inevitable.

[amoebapower]

as to what was said earlier, i dont believe viruses die because they are not techinically "alive" in the first place. for example chicken pox. once you get it, you dont get it again, although the virus has remained inside of you. only sometimes the virus flares up causing shingles. thus, viruses never die.

[Dustfinger]

Are viruses living organisms now or not ?

[kotoreru]

Nooo...they have no metabolism.

[mcar]

Death is irreversible. That's it.
Evolution irreversible according to Dollo.
Death is simply the end, evolution progresses.

[AstusAleator]

And ironically the death of this thread doesn't seem to be very permanent