I discovered that immortals are not alive by biological standards

So yeah, apparently for something to be considered alive it has to

• Be made of cells
• Evolve
• Reproduce.

Any immortal being would lack at least one of those traits.

Am I interpreting this wrong? Is my biology teacher batshit insane? Or is it correct, and an immortal being would cease to be alive? What are your opinions on the matter?

Er, which one of those three would an immortal being (e.g. human) lack? And immortality, in essence, is the inability to die, not the loss of ability to live.

The loss of ability to live is death.

I'm glad you've got an absolute definition of life in the universe, but perhaps the universe has ideas of its own.

That is to say, if your definition is narrow enough, you can exclude anything.

That particular set of criteria excludes viruses and related organisms, prions, and all infertile animals.

edited 31st Jan '11 7:27:39 AM by BobbyInTheLibrary

A being can be made of cells and reproduce and have its offspring undergo evolution without needing to have a limited lifespan.

That said, being able to evolve is not necessary to the definition of life, although adaptation to stimuli in some form is. "Made of cells" is also an overly narrow interpretation of the organization clause.

edited 31st Jan '11 7:28:30 AM by Desertopa

Two of them. Organization and reproduction.

Ninja'd. "Overly narrow"?

edited 31st Jan '11 7:30:41 AM by BobbyInTheLibrary

I was going to say that eating and reproduction are the primary elements of life, but the wikipedia article adds quite a few more. Growth is a good one, too. An immortal being could easily qualify as alive if it consumes sustenance, metabolizes it for energy, has a cell growth cycle, and is capable of reproduction, whether it exercises that capability or not.

Ninja'd my edit, but while "made of cells" is adequate for the purpose of classifying life on Earth, it's widely agreed to be unreasonably restrictive with regards to classifying hypothetical forms of life which might be engineered or exist elsewhere in the universe.

Right, that seems overly restrictive. Any form of internal organization should be sufficient.

Oh, I see what you mean.

I think any set of criteria that excludes viruses and prions is already too narrow, though. Whether or not they're regarded as alive by science, they behave as though they are.

So I assume we're going with 'my biology teacher is batshit insane'?

Good, good. I was getting worried for a minute. Not just about immortal things, but also aliens that might not be made up of cells.

No, not unless you want to call the mainstream scientific opinion batshit insane.

Some criterias I learned: Responding to changes in the enviroment, growth, exchange of energy and matter, (self-)reproduction.

Please note that there's alot of different opinions in the world wether virus are alive or not.

I'm admittedly biased towards broad interpretations of life; one of my favourite things about science fiction is the idea of sapient rocks/plants/crystals/machines/abstract concepts.

I understand that scientists have to draw the line somewhere, but it seems intuitive to me that viruses would be considered living things. I haven't conducted a survey or anything, but I imagine most laypeople would regard them as such.

Mh, that could be true for the US. (I thought I heard they teach them as being alive.) My education featured them as not being alive because they can't reproduce without other cells and don't have a metabolism, don't grow. (I hope this is right, if not someone could please correct me.)

So, it could be split by countries in laypeople, right?

If it's not about science I'm in love with the nature animism too. It kinda adds to my fascination of Shinto.

edited 31st Jan '11 7:58:06 AM by myrdschaem

Teacher specifically drew out the points in the OP on the chalkboard.

Also, no, U.S. schools teaches that viruses are not alive.

I don't think my class gave a definite opinion either way. It was just noted that there was some disagreement among the scientific community regarding the classification of viruses.

Animism is cool, but that wasn't what I meant.

edited 31st Jan '11 8:00:57 AM by BobbyInTheLibrary

Mine as well. Many years ago.

edited 31st Jan '11 8:00:44 AM by Fighteer

I was this thread was gonna be about Highlander.

edit: god damn it I keep forgetting the syntax for potholes in the forums.

edited 31st Jan '11 8:14:22 AM by nightwyrm_zero

It's the same as on the Wiki. {{Highlander}} = Highlander.

Ah, it's the squiggly brackets, I kept trying to use the square ones.

I believe my (GCSE) Biology class said something like "viruses are alive, even if they do not show [things on this list]". Not in so many words, though.

Well, you can make it about highlander if you like!

I really think it depends on what kind of immortal we're talking. Say, for example, our subject is a vampire. They move, they can react, they take matter in (Side question: what do they do with it once the juice was processed? Do vampires piss? Just sweat it out? Maybe all that sparkling is actually radiation?). Some version identify them by growing nails/hair. And is converting new vampires reproduction? Or maybe we can define vampirism as a condition that negates the usual ability for reproduction? So are the undead alive?

@Bobby What did you mean, then?

AlsoLOL Twilight causes cancer

By 'immortal' I mean does not age, regenerates cells perfectly with no decay, pretty much impossible to kill, et cetera.

Wait, what. Evolution doesn't apply to individual organisms. Evolution acts on a population or species.

Yeah I guess you do mean "attempts to adapt to the environment", just don't use "evolve" to mean that unless you're trying to write figuratively :P

School always taught me viruses weren't "alive". I never thought this was weird o__O

Diamonnes, are you referring to entities like ghosts and gods? They might behave vastly differently from cellular life, I'd imagine.

I meant like, for instance, the idea of an Artificial Intelligence that rivals actual human intelligence. Or the idea of creatures made out of minerals, like the Discworld trolls. Or abstract creatures, like the angels from Doctor Who (which do reproduce - by implanting their images in the minds of others). Or plants that behave like animals, such as Triffids and suchlike. It Can Think is related.

edited 31st Jan '11 8:40:08 AM by BobbyInTheLibrary