Thoughts on Abiogenesis

[Subduction Zone]

Abiogenesis is a term that was given to mankind when reverse-engineering evolution hit a brick wall.

Basically the term means: "Just take it for granted it happened."

No, that is what you do. Scientists can never do that.

 

[Occams Barber]

I wonder if reverse engineering is a good way to tackle the problem. I can't find my copy of Dawkin's book 'The Ancestors Tale' right now. Rather than saying 'This is where we started from' and working forwards, he starts with us and works backwards through time, stopping off at various points where we had a common ancestor. But I can't remember how far back he went and what his thoughts were on abiogenesis (been years since I read it).

I don't know if it might be a better approach to start with the most basic conglomeration of cells etc that all would agree with is 'alive' and then start removing aspects of it's construction until someone says 'No, that's the point where it's not alive'. And then we have what they consider to be the difference between life and non life.

Funny you should mention this. My late night 'going to sleep' mental exercise last night was (mentally) cutting a piece of living matter into increasingly small pieces. The object was to decide at what point I'd crossed the barrier between life and non-life.

At first I decided that cutting a cell in half crossed the boundary. Then I wasn't so sure. Are there any cell bits which could stand alone as life? Is a wriggle of DNA/RNA 'alive' or have I just described a virus? I recall reading somewhere that the jury was out on whether a virus is 'life'.

Then I fell asleep.

OB

 

[Subduction Zone]

At present there no known bright line distinction between
living and non living.
Of course there is no precise definition of life.
IMO there's a continuum with no non arbitrary way to
say if something at the margin is alive or not.

To quote you:

"Zactly". And that is strong evidence for abiogenesis over creationism. If creationism was true one would expect to see a hard line between "alive" and "not-alive". Just as the so called "species problem" is really only a problem for creationists. The theory of evolution predicts fuzzy borders almost everywhere.

 

[Bradskii]

I mean, the organic chemistry which is underway on Titan, (for example), is considered as being worthwhile investigating, as it would be a good test bed for some Abiogenesis models.
What kind of organic chemistry goes on there?; what reaction products persist?; how does the low temperature environment affect complex chemistry reaction processes (compared with Earth's)?, are three meaty questions arising from our own pre-biotic chemical models.

Any updates to the definition of 'life', coming from research on the surface of Titan, would be an outcome of that research ... whereas any definition of 'Earth-life' would be more or less a moot point as far as that research is concerned.
Investigation into an unknown, like the Titan organics environment, would not feature Earth-life's definition(s) .. in fact doing so, would likely just end up biasing the results.

I don't see that the definition(s) of life could be changed to suit some extra terrestrial environment. If it has all the characteristics of life then it's alive. If if has none, it isn't. if it has some, then...you pay your money and you make a choice.

'It's life, Jim. But not as we know it' means that it has enough of the characteristics but in a form with which we are not familiar.

 

[Occams Barber]

To quote you:

"Zactly". And that is strong evidence for abiogenesis over creationism. If creationism was true one would expect to see a hard line between "alive" and "not-alive". Just as the so called "species problem" is really only a problem for creationists. The theory of evolution predicts fuzzy borders almost everywhere.

I doubt that a creationist could ever accept a fuzzy boundary between life/non life since it would have ramifications for their religious belief.

I imagine they could invent an undefined word, similar to 'kinds', to confuse the issue. I am going to recommend 'splurgle' as an overarching creationist term for life including all cases which are scientifically fuzzy.

Example
OB : "A virus may or may not be alive"
Creationist : "No my son - it's definitely splurgle"

OB

 

[Astrid]

I mean, the organic chemistry which is underway on Titan, (for example), is considered as being worthwhile investigating, as it would be a good test bed for some Abiogenesis models.
What kind of organic chemistry goes on there?; what reaction products persist?; how does the low temperature environment affect complex chemistry reaction processes (compared with Earth's)?, are three meaty questions arising from our own pre-biotic chemical models.

Any updates to the definition of 'life', coming from research on the surface of Titan, would be an outcome of that research ... whereas any definition of 'Earth-life' would be more or less a moot point as far as that research is concerned.
Investigation into an unknown, like the Titan organics environment, would not feature Earth-life's definition(s) .. in fact doing so, would likely just end up biasing the results.

I bet it will be exciting, whatever is going on!

 

[AV1611VET]

I imagine they could invent an undefined word, similar to 'kinds', to confuse the issue.

Like ... say ... "genus"?

And if "genus" doesn't qualify as a definition, would it qualify as a synonym?

 

[SelfSim]

I don't see that the definition(s) of life could be changed to suit some extra terrestrial environment. If it has all the characteristics of life then it's alive. If if has none, it isn't. if it has some, then...you pay your money and you make a choice.

The point about Titan goes, (I disagree with this approach .. but it has been published and presented by scientists): 'If there is life on Titan, it will be vastly different', (in more or less words than my quote there).

So, if they're going to use the word 'life' in that statement, then the statement implies (logical) self contradiction because the base bio-chemistries of life on Earth, produce the biochemical processes and products which are used to test for it .. Titan's physical and chemical environment doesn't allow for those same processes and products, so therefore detecting what we call life, won't happen using those same bio-chemical tests. So, the definition of 'life' will have to change in unknown, (at present), ways, in order to resolve the contradiction implied in the statement. That can only be done in situ .. (and not before that).

 

[Bradskii]

The point about Titan goes, (I disagree with this approach .. but it has been published and presented by scientists): 'If there is life on Titan, it will be vastly different', (in more or less words than my quote there).

So, if they're going to use the word 'life' in that statement, then the statement implies (logical) self contradiction because the base bio-chemistries of life on Earth, produce the biochemical processes and products which are used to test for it .. Titan's physical and chemical environment doesn't allow for those same processes and products, so therefore detecting what we call life, won't happen using those same bio-chemical tests. So, the definition of 'life' will have to change in unknown, (at present), ways, in order to resolve the contradiction implied in the statement. That can only be done in situ .. (and not before that).

Let's say that they find life that is based on silicon as opposed to carbon. Utterly different to forms of life that we know. But...whatever they describe as life must satisfy the characteristics of life - whatever form it takes. So it must grow and change, react to the environment, reproduce, have a metabolism etc. Or have enough of the characteristics that define life so that we can deem it 'alive'.

 

[Occams Barber]

Like ... say ... "genus"?

And if "genus" doesn't qualify as a definition, would it qualify as a synonym?

Wake up AV. I've just done the job for you by recommending "splurgle" as the Creationist goto word for life in all its fuzziness.

OB

 

[AV1611VET]

Wake up AV. I've just done the job for you by recommending "splurgle" as the Creationist goto word for life in all its fuzziness.

What do you recommend for "child in the womb"?

(Let's see your humor now.)

 

[Bradskii]

What do you recommend for "child in the womb"?

(Let's see your humor now.)

I'll go 'Stages Of Pregnancy' for $200.

What is a zygote?

 

[AV1611VET]

I'll go 'Stages Of Pregnancy' for $200.

What happened to "splurgle" all of a sudden?

 

[SelfSim]

Let's say that they find life that is based on silicon as opposed to carbon. Utterly different to forms of life that we know. But...whatever they describe as life must satisfy the characteristics of life - whatever form it takes. So it must grow and change, react to the environment, reproduce, have a metabolism etc. Or have enough of the characteristics that define life so that we can deem it 'alive'.

.. and those characteristics change depending on the physical context (the environment) and on the behaviours of the specimen within that context. Their preconceptions (including the definition of life) of 'how life must be', (in your scenario there), could quite easily be completely amiss in a really non-earth-like context.
No matter how much they talk it up, they don't know what they're looking for until 'a specimen of interest' shows up in some radically different non-earth environment. In the case of Titan, the arm-wavers have conjured up a scientifically meaningless lifeform called a 'methanogen' (because it will have to based on the methane). However the term 'methanogen' only has meaning in an Earth-life context. We have anaerobic methanogens here on Earth .. but their base chemistry is still related to all other Earth-life .. which will be nothing like Titan's. The term is being abused for the sake of stirring up interest in alien life.

What I'm saying here is that the definition of life is totally context dependent. We will have to restart the process of redefining it in the context of an alien landscape and our preconceived definition/notions and tests for it, will also have to be restarted from scratch in that new context.

 

[Bradskii]

What happened to "splurgle" all of a sudden?

It's a creationist word.

 

[AV1611VET]

It's a creationist word.

OB is a creationist, is he?

I wasn't aware that was an option available to atheists.

 

[Bradskii]

.. and those characteristics change depending on the physical context (the environment) and on the behaviours of the specimen within that context.

The characteristics are not environment dependent. But I'll be quite happy to agree with you if you can come up with a different set of characteristics we could use for life in an alien environment.

 

[Bradskii]

OB is a creationist, is he?

I wasn't aware that was an option available to atheists.

No, it's a word he suggested for use by creationists.

 

[AV1611VET]

It's a creationist word.

It is!?

The dictionary says otherwise.

But what I want to know is, if OB thinks a child in the womb is a splurgle?

 

[Occams Barber]

It is!?

The dictionary says otherwise.

It's already in the Dictionary?

That was quick. I just invented it an hour ago. Them Oxford boys are really on the ball.

OB