malookiemaloo

First of all I do not come from a science background. I could not even define evolution.

However one thing has puzzled me about evolution and that is 'why do humans, animals plants etc die?'.

From what little I have gleaned, evolution is about improvement, better, higher, onwards and upwards greater intelligence (can intelligence evolve?) but suddenly death comes in. It seems to me that death runs counter to evolutionary principles. Any views?

I am sorry if the question is a naive one but it is genuinely asked.


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Wounded King

Evolution is by no means as progressive as you suppose and certainly not about overall improvement. Fitness need only stretch as far as reproductive age in evolutionary terms, an organism only needs to be able to survive long enough to pass its genes on to a further generation to be considered successful, after that natural selection couldnt really care less what happens to it. Obviously the strategy of many relatively transient gene copies produced instead of a few very long lived ones. This may be related to the different reproductive strategies favouring many low investment offspring or few high investment offspring, K strategies etc.. It certainly reflects on the fact that the longer lived an organism is, in general, the smaller the populations are.

Jayjay

Bacteria never "die" of old age, they just keep multiplying. I suppose you could say that the cells of your body have lived for billions of years too, just that a majority of them have recently (i.e. after you were born) specialized in order for a few cells to live on.

Godless Dave

That is an incorrect description of evolution. It has nothing to do with better, higher, onwards and upwards, or greater intelligence. It's about surviving long enough to produce offspring.

malookiemaloo

Surely there must be more to evolution than mere survival?

Is an 'evolved' species not superior in some way to an 'un-evolved' one?


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Godless Dave

All species have "evolved" to where they are now, so I don't understand your question.

Monkeybot

An organism has two goals:

1. Survive
2. Reproduce

From the standpoint of natural selection, that's all that really matters. An organism could explode directly after mating and that might not be selected against (well, depending on whether or not the organism damaged its offspring in the blast, I guess).

Valentine Pontifex

Others have already pointed out that evolution does not necessarily mean "progress" and that Darwinian fitness means having more copies for future generations.

But there another problem. How can you get rid of death? Life is complicated and if disrupted enough will not be able to function. Certainly things that can destroy living beings are not going to go away. Get eaten by a predator and you will die. Sure your species can evolve to make it harder on the predator but then again the predator's species can evolve ways to make it easier to get lunch. The same goes with germs. And certainly the enviroment has things that kill that it not reasonable to expect evolution to defend against.

When it really gets down to it: it was not until the 20th century that there was a species which a significant percentage of the population did not die before "old age" had a chance to get them. Lets say people magically stopped aging at 40: until recently in historical terms it would not have that much difference on how long they lived since so many things can and did kill them. Not becoming old will not keep one from dying.

And lets pretend that we can stop aging, disease, etc. We will not be able to stop accidents. There will always be a finite chance that an accident will do enough damage to kill us.

Finally though it will not happen for billions of years, the universe around us will not be one that can be lived in forever if the current understandings are even remotely true.

malookiemaloo

You seem to be saying that evolution is synonymous with survival. Surley evolution is more than that? Do evolving species not change in addition to surviving?

Monkeybot. Is natural selection not completely different from evolution? After all a creationist can easily believe in natural selection. To deny natural selection is sheer stupidity.

None of which answers the question how can death evolve?!


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Monkeybot

Malookie,

I suggest you spend some time at Talk Origins. Honestly, they explain things better than I ever could.

Natural selection is not evolution, but it is one of the mechanisms by which evolution occurs. Sorry if I wasn't being clear enough. At the same time, I honestly don't see how you can talk about natural selection without talking about evolution and vice versa.

What is evolution?

As mentioned in that link, evolution is merely the change in frequency of alleles within a gene pool from one generation to the next. There's no real sense of "progression," in fact, that's a view of evolution that's been considered and discarded as erroneous.