Zadok001

No, I'm not going to attack evolution by arguing against abiogenesis, despite the title.

I am not a biologist, nor do I study biology. As a result, what I'm about to say may be incredibly stupid. It's also possible, indeed, even likely, that I will misuse terminology. I hope you'll be able to dig my actual meaning out of the mess this post will most likely end up as.

I've seen a fair number of theists argue that life cannot arise from non-life, and therefore a divine force must exist to make this transformation. It has recently occurred to me that this argument may not just be falliable, it may be entirely non-sensical.

I postulate that the distinction between 'life' and 'non-life' is a non-existant one. AFAIK, we have never been able to adequately define 'life.' Attempted definitions tend to include fire, or exclude some forms of bacteria. Viruses are, likewise, unclassifiable by many standards of distinction. Life-forms, as we know them, are simply very complex combinations of chemical and physical reactions - An enzyme here, a protein there. The only thing 'unique' about life is that it tends to replicate versions of itself. But this is something we see on a chemical level fairly regularly - In crystals, for example.

As such, it seems impossible to reasonably say that 'life' is different from 'non-life' on any level other than a semantic one. The entire conceptual term 'life' seems to be effectively useless.

So, in order to claim that 'life' cannot arise from 'non-life,' we need some kind of clear distinction between the two. Since 'life' seems to be unclassifiable, it is impossible to draw such a distinction; therefore, claiming that life came from non-life is the equivalent of claiming fire came from fire. Technically correct, but utterly useless.

It would seem that in order to show this postulate false, one would need to show a clear distinction between life and non-life.

Asha'man

I agree with you, Zadok.

In my mind, life is nothing but a very complex, self-sustaining, chemical reaction. The only difference between life and other chemical reactions is a level of complexity.

There is no difference between the carbon atoms in a living organism and a dead one, except for context. Life is not a property of matter, it is merely a process.

Eric H

I can put a spider and mankind in the same group, we might call life, but I am struggling to group crystals and fire in the same category as a spider.

This has nothing to do with complexity I just can’t see it.

Peace

Eric

Godot

You sell yourself short zadok. A not unreasonable argument you've put forth, but something about it mislikes me. Can't quite figure it out though. Figured it out: that bit about the fire and crystals sends up a red flag for me. Any chance you could elaborate on that a bit further? Could be a promising discussion!
Your line of reasoning won't fly with a fundy at any rate. One of them thinking that evolution is "goo to you through the zoo" wouldn't begin to understand the distinctions made between living and non-living matter.

GunnerJ

An interesting link on the subject.

Zadok001

Eric H and Godot:

Sorry, I was referring to an old debate I had with someone. I assumed it was more common knowledge than it apparently is.

Someone once tried to define life as any entity which consumes raw material, lets off energy, and can reproduce with variation. Fire fits this definition. So does the formation of some crystals. Hence, the reference - It's hard to define life such that fire or crystal doesn't slip through.

If need be, ignore those references - The rest of the argument functions independant of those two specific examples.

Godot, I can't quite convince myself this argument works either. It *seems* functional, as we really can't define 'life,' and it seems that life is generally just a long-term chemical and physical reaction. Despite that, something seems wrong. I was hoping someone here could help me.

GunnerJ:

Thanks for the link, that clarifies my fire comment. None of the definitions presented there will allieviate the problem, though. We still can't reasonably distinguish life and non-life.

RBH

Biological life displays one characteristic that fire does not: descent with heritable variation. While a 'parent' fire can ignite a 'daughter' fire, the daughter fire's properties (color of flame, mean temperature, rate of spread, composition of by-products, likelihood of daughter's 'reproduction,' etc.) depend solely on the immediate environment (fuel + oxygen) of the daughter fire and not at all on properties of the parent fire. Fire does not create lineages in which lines of descent can be reconstructed by examining properties of individuals in the series of fires.

That is not to say that fire "lineages" cannot be reconstructed by other means - I do this regularly in my capacity as an officer of a volunteer fire department. But one can't examine properties of fires themselves to ascertain lineages, and not merely because parent fires are no longer available for direct examination. The reconstruction is always based on external factors like wind, ventilation routes, and so on. Fires do not have a means of transmitting information from generation to generation, like DNA, and hence have no inter-generational "memory," no lineage. And inter-generational memory is what enables the processes of mutation (imperfect transmission of generational memory) and selection, and hence evolution, to occur.

RBH

Majestyk

Depending on the level of detail contained within the definition, there can or cannot be a distinction made. "Life is a chemical reaction" this definition is also shared by a number of other phenomena.

However, refine the detail of the definition to include, "descent with heritable variation.", as provided by RBH, and you have reduced the number of phenomena that can share this definition.

Continue in refining the detail of the definition and you can exclude bacteria, and then, fungus, and so on. *edit* not to say you can continue to exclude from the definition of life. Just that your resulting definition becomes increasingly exlcusive.

I suppose you may call it a matter of scale. From the quantum to the cosmic, the term "life" has meaning in only a very narrow range of scale.