I still believe the idea of immortality is silliness, and I just thought of a good reason why:

Assuming the universe is trillions of years old, life at least as complicated as ours should have come around before us. If that is true, and inconsequential immortality was a possible venture, they would have discovered it by now. If that is true, the universe should be teeming with life, since the rate of reproduction would be ever expanding with no limit in sight. And if that is true, we should've made contact by now.

But we haven't made contact, thus all of our hypothetical precursors didn't reproduce indefinitely, thus they didn't achieve immortality, and so I highly doubt we will either. In fact I'd say it's downright arrogant to think we ever would, regardless of your point of view, since it's quite obvious nobody else has done it yet.

EDIT: Just found the right term for "inconsequential immortality," which is actually called biological immortality (which means that you never age, but you can still be harmed and even killed).

As it happens, there is a certain type of jellyfish that is potentially biologically immortal, as it can reverse its life cycle by transforming back into a polyp, thus escaping death. These jellyfish are not much more common than any other creature on earth, however, as they are extremely vulnerable to predators in the polyp stage and they are still vulnerable to disease as well.

But, if we somehow able to create a biologically immortal human mutant by stealing genes from this jellyfish, we would have, for all intents and purposes, a biologically immortal man.

Immortality (we have always been talking about the "inconsequential" one) wouldn't make the universe teem with life, because it wouldn't grant us the ability to live on other planets or to travel fast enough to reach other solar systems. Mind that the fact that you don't age doesn't mean that you wouldn't want to go on a trip that lasts a million years and that you could get enough food on that spaceship for that trip or that you reach a planet within ITS lifetime!

Also, reproduction does have a limit. If you don't age, you can still starve to death. So the food, or rather the energy on Earth effectively limits the number of individuals that can live on Earth.

EDIT:


I didn't check if that thing with the jellyfishes is true, but you just contradicted yourself.

Challenge accepted. I will start when I'm death and I'm also reducing it to 0 kcal/day.

The jellyfish:
http://en.wikipedia.org/wiki/Biological_immortality#Jellyfish

I didn't actually contradict myself. I said human beings would never become immortal, and I stand by that belief. That jellyfish is potentially immortal, and if you mixed its genes with ours you might end up with an immortal human, but that's assuming the "gene mixing" is even possible in the first place. And if it is possible, and we learn how to do it, who's to say we actually will get the chance to do it? Think of the controversy that would spawn if someone announced they were going to create a new subspecies of humanity. And of course there is still the question, if you add unfamiliar genes to a human being, is it even really human any more?

Also this is a learning process for me, I'm not pretending to be an expert. I'm just telling you what I've read so far, so my stance may change on this issue very rapidly. I suppose you can say I'm following ideas as I post.

EDIT: Oh yes, there are other issues. The jellyfish is supposedly immortal, but we reached that conclusion through extrapolation. It appears to be immortal from what we've seen of it so far, but perhaps there are other processes involved in the fish's biology that will prevent it from living forever, regardless of its outer conditions?

uhhhhhhhh its not. its ~15billion years old. I havent finished reading though.

EDIT:

im talking in consequential and inconsequential since we are pushing both fields. some scientist are working on storing conciesness in an electronic way on a computer, while others are working on cures to aging in general. I'm more convinced that the first one is the closest to have any likelihood near our lifetime. but yeah 15 billion years is not enough time to be "sure" there was enough life already created to contact us, or that they were intelligent enough to create the technology/gather the resources to get here yet.

My guess was just that - a guess. I have no idea how old people generally think the universe is. I believe that in reality the universe is < 10,000 years old, but that's coming from a creationist's point of view.

Keep in mind that as I told Lukas, I'm not attacking anyone. I'm following my own harebrained train of thought, and I'm posting as I go. That, and I'm following a lot of different hypothetical situations - like the existence of aliens, etc.

oh no i didnt mean that as an attack, more like an update for ya. and yeah i figured this is kinda new territory for you. no offense meant.

http://www.amazon.com/Shattered-Self-End-Natural-Evolution/dp/0262025027

"At the dawn of the 21st century, Baldi (a professor of computer science and biological chemistry at UC-Irvine) says, the human genome has been mapped; genetic technology can prevent inherited disease; and biogenetic techniques such as cloning and in vitro fertilization make it possible for people to choose traits for their babies. How, he asks, does such burgeoning scientific achievement alter the nature of the human self? How does cloning, for example, change our conception of ourselves? Is a clone a human being? Is a full-term in vitro aka test-tube baby a human baby? What are human attributes? Baldi observes that "our notions of self, life and death, intelligence, and sexuality" are primitive and evolved to provide us with "a feeling that each of us is a unique individual delimited by precise boundaries." He contends that a world dominated by computer and biotechnologies shatters this model, making us uneasy with scientific advances. For example, in vitro techniques may render sexual intercourse unnecessary for conceiving children. Thus sex, perhaps the clearest evolutionary example of human will to survive, could become extinct. Baldi provides an accessible overview of molecular biology and a masterful survey of scientific techniques, like DNA-manipulation, that challenge our sense of ourselves. While he finds many of these scenarios disturbing, he emphasizes that, in the quest for self-knowledge, we must face these scientific challenges openly. Baldi's powerful, elegant book deftly navigates the interactions between science and psychology. (May)Forecasts: While Robert Wright and E.O. Wilson focused on evolutionary theory as it demonstrates the emergence of self, Baldi goes further to show how the self evolves after natural evolution has ended. Readers of Wright, Wilson, Steven Pinker and Richard Dawkins will enjoy Baldi, so this title could do relatively well with attentive handselling."

this sounds like a very interesting book related to our topic.

Why do people get old and die?

There is a simple reason: evolutionarily it did not matter if they die at older age.

It the simple rule that things wich are not nessecary will not
dominantly develop in evolution.

Humans live quite long for a mammal, one of the longest lifespans. Only few other mammal species live as long or longer.
(Elephants, Whales etc) Mostlely Animals who have a high
investment to raise their young.

These mammal species specialized in bringing up few young and
extensively invest time in them.

Species who spawn many offsprings (like rodents)
specialized on many offsprings with lower investment in the individual.
These species typically live much shorter.

Now humans probabbly optimized to raise about 4 to 5 offsprings
per woman, starting to reproduce at the age of around 12 to 14. Also twins are few. So humans are a typical 1-offspring species.

Investment in the children had to be at least 8 to 10 years for
it to become independant enough to be a productive member of the group and require less care by the mother.
So the lifespan of women and men up to around 30 years was enough to serve
this reproductive purpose. Its typically the age where people start aging more quickly.

At the harsh conditions back then, most did not make it over 40 anyhow. Life expectancy was much shorter than today.
A few older members where shurely beneficcial (sharing knowledge)
But having a higher percentage of old members would not have benefited the group, and rather slowed it down.
The reproductive and childraising age (for own offsprings) was
over at this time.

There was no evolutionary pressure to keep full health at this age.
So the genes never adapted to support a higher lifespan.
Its not a "killswitch" but rather a lack of optimization to
keep life (the organs and cell) healthy and from deteriorating after such a long time.
It requires costly protection and repair mechanism and thus energy to keep
tissue healthy over long periods.


Image a different scenario: each female can only have one child
in 5 years (because there are 5 year long winter cycles or so)
In this case we would have evolutionarily adapted to live quite longer.
Maybe to keep young and at full health up to 80.

But there was never this pressure.

Nowerdays we live much longer than the original lifespan,
But there the effects of non-repairing tissue kick in.
The aging starts and since we have a much more convenient environment then the club swinging caveman
we can life much longer with pretty overdue organs.

The reason is not so simple: A species with no aging, in combination with other factors such as being not too low in the food chain, had a huge evolutionary advantage. It could grow much more rapidly. In fact it is absolutely not clear why evolution has not developed immortality of most higher species.

A plausible theory is that a non-aging species would not be able to evolutionary evolve further, and thus are stuck in a primitive state and in evolutionary niches.