Thread: alive,

I KNOW I LEARNED THIS ALONG THE WAY! but i dont remember

so i have come to you ...my friends ,

tell me, what is the defination of somthing that is alive,

is it a number of neccary requirmntsa or sumthing like that?
i know i know i should know this! but i don't!

I believe the ability to digest has something to do with it (I've looked up digest from the dictionary, dunno if it's what I mean. I mean like being able to extract food from matter).

ood good
food, yes thats it, food is the key

I'm not really sure. Some viruses are still being debated as to whether they are alive or not. I say... yes, but it's not easy to prove.

Hi gg3,

The most agreed upon fundamental definition is the ability to replicate, metabolise, and be contained in some way to do both the above. This essentially means undergo Darwinian evolution.

Ditto for what TB says. Its fundamentally the ability to metabolize, maintain internal order, be motile (to some extent), as well as to pass on genetic information.

tell me, what is the defination of somthing that is alive,

According to Adams- anything that goes 'squoosh' when one steps on it.

But in seriousness, something is alive that seeks protection and progression- the virus likes to sneak into my nice little definition to make me look stupid but my point stands.

So, for the pesky virus we elaborate.
Something is alve that seeks protection and not only progresses but resists the natural tendency towards chaos via a medium cultured in its body.

This is the defintion of a body. Therefore, the defintion of life. Therefore, does not apply to virus.

I would say that another aspect of being alive, is the ability to reproduce in some way, and I suppose this would also include a virus.

I would say that another aspect of being alive, is the ability to reproduce in some way, and I suppose this would also include a virus.

It cannot reproduce.
It can steal and manipulate, but technically, not reproduce.

So of all requirements, its this one lacking and its inabilty to metabolize, that disqualifies its claim to 'lifehood'.

(admit it 'walker, you're bored)

Originally Posted by goodgod3rd

tell me, what is the defination of somthing that is alive,

“ ‘Life’ and ‘living’ are words that the scientist has borrowed from the plain man. The loan has worked satisfactorily until comparatively recently, for the scientist seldom cared and certainly never knew just what he meant by these words, nor for that matter did the plain man. Now, however, systems are being discovered and studied which are neither obviously living nor obviously dead, and it is necessary to define these words or else give up using them and coin others.”
—British virologist Norman Pirie, c. 1934

Life is tricksey. It has one meaning philosophically. And quite another physically.

Look closely enough at any living thing and that 'life' falls apart. Shredding into tatters.

The virus is one example.
As it has been pointed out already, many do not consider viruses to be alive. Because they lack the full molecular machinery with which to replicate themselves. They have to 'borrow' a cell's machinery to do the deed.

“Attention of biologists was distracted for nearly a century by arguments over whether viruses are organisms. The disagreement stems largely from the generalization put forth in the latter half of the nineteenth century that cells are the building blocks of all life. Viruses are simpler than cells, so, the logic goes, viruses cannot be living organisms. This viewpoint seems best dismissed as semantic dog wagging by the tails of dogma.”
—American evolutionary biologist Paul Ewald, 2000

And yet. The deed is done. Viruses replicate. Prodigiously. They evolve and evolve in quite sophisticated ways. Witness the wild hijinks of the HIV virus as it goes through it's replication cycle.

And what of mitochondria? It's been conjectured that mitochondria were once a free-living organism. They existed on their own until some fateful day when they fused with single cells and started the chain of life that stretches to us.

“Whether or not viruses should be regarded as
organisms is a matter of taste.”
— French Nobel laureate André Lwoff, 1962

Life is a word and like so many words falls short of the goals of science.

We can easily distinguish a rock as 'not alive' and a protazoan as 'alive'. These distinctions between such wildly disparate categories are where the term originally evolved and is where it works. But the divide between cell and virus is to narrow for the bridge of 'life' to span.

Nomenclature is the key.

Originally Posted by Abraxas

Something is alve that seeks protection and not only progresses but resists the natural tendency towards chaos via a medium cultured in its body.

Then explain the lemming.
And the goth child.

As to the 'natural tendency towards chaos'... Isn't chaos actually utilized to further life? Think heat.

According to Adams- anything that goes 'squoosh' when one steps on it.

Like a twinkie?

To be alive means to be active. They have to be doing something. Trees are alive since they are in a constant process of photosynthesis. Humans are alive since we are breathing. In someway, you have to be doing something.

Originally Posted by poly_nightmare

In someway, you have to be doing something.

Are proteins alive?

I always keep a deictionary nearby, and this definition seems to encompass much of the previous discuaaion:

The property or quality that distinguishes living organisms from dead organisms and inanimate matter, manifested in functions such as metabolism, growth, reproduction, and response to stimuli or adaptation to the environment originating from within the organism.

By definition, it will have at least one of these characteristics. Then technically speaking, a virus would be classified as life, and protein would not. While protein can react to the environment, this is usually with the help of enzymes inside a controlled system. Viruses do defy some common definitions though, but I would think of a virus as being one of the most fascinating forms of life because of its abilities compared to its size and the viruse's ability to survive in harsh environments.

While protein can react to the environment, this is usually with the help of enzymes inside a controlled system.

Enzymes are a type of protein.
All movement, all signs of life, are caused by proteins in their various forms.
But nobody considers proteins to be alive.

It's as I quoted above. The problem lies in the closeness of modern scrutiny. When people considered the single cell to be the smallest unit of life, then everything was hunky-dory. But we are looking at a finer and finer degree of accuracy.

Just as ordinary physics disintegrates at the quantum level, so too does lay interpretation of words such as life and living.


And. If you want to stress the 'controlled environment'... our bodies are also a controlled environment. So. The cells in our body are only capable of surviving because they maintain a controlled environment in which to survive.

[quote="Abraxas"]

I would say that another aspect of being alive, is the ability to reproduce in some way, and I suppose this would also include a virus.

It cannot reproduce.
It can steal and manipulate, but technically, not reproduce.

So of all requirements, its this one lacking and its inabilty to metabolize, that disqualifies its claim to 'lifehood'.

---Abraxas

. . . a good point, but think of all the parastic plants and animals which could not reproduce without a host. Certainly, the virus is a different form of life, but we really need to get used to different forms. The universe must be filled with them! I can even build a strong case for societies ("social organisms") being a form of life. I can show a definite life cycle, a means of genetic-type evolutionary adapting, and a (not very sexy!) reproductive process.

charles
http://humanpurpose.simplenet.com

I like the explanation given by Erwin Schrödinger in 1946 ("What is life")

Life keeps his entropy-level at a given state by eating negative entropy

The property or quality that distinguishes living organisms from dead organisms and inanimate matter, manifested in functions such as metabolism, growth, reproduction, and response to stimuli or adaptation to the environment originating from within the organism.

For something to be called living it must have all the properties listed above. Viruses have no metabolism and they have no independant reproduction and are, in a biological sense, not living. Viruses are referred to as organised particles.

I'd say that somthing is alive if it is subject to darwinian evolution

Originally Posted by jolko

I'd say that somthing is alive if it is subject to darwinian evolution

Thats a nice try, but the early Hypercycles already competed for resources without being living. They were subject to evolution without being living.

oh I was unaware of these Hypercycles I guess i'll have to think again.