Evolution and abiogenesis

[Hlafordlaes]

What are you calling a "darwinian replicator"?

The current theory is RNA molecules were replicating before abiogenesis. Are you calling the first RNA molecule the first abiogenesis?

Are you saying selection pressures were not acting on those molecules?

<snip>

I supposed you could divide evolution theory up and call everything that happened up until life began is part of the abiogenesis stage and everything after is part of the evolutionary process stage. Both are affected by random molecular occurrences and selection pressures.

Nice.

As common processes are at work, what constitutes life becomes even more apparently a matter of definition. What should we call it... the genesis of the encoding of progeny instead of directly replicating a molecule?

 

[Slowvehicle]

Abiogenesis is a necessary condition for biological evolution to get started. It's a fair tactic in a debate to attack X by attacking the necessary conditions for X.

No, not really.

Life is a necessary condition for evolution by natural selection to happen. How the life got there is immaterial.

 

[Slowvehicle]

The two are inextricably linked. Why do you think there are so many experiments in biology to recreate primordial conditions and get life from organic compounds? If it happens, it will be big news, because evolution theory is not complete without an explanation of how life began.

It's like that old creationist saying, "Give me one miracle, and I can explain everything else."

No, not really.

However living things came to be, the process of evolution by natural selection can be observed to work. Life itself is the necessary condition (which is why the "you don't see watch-pieces evolving into a watch" argument is so manifestly stupid).

 

[Slowvehicle]

I don't think biologists who believe in the standard account of evolution would be satisfied with a magical explanation for how life originated- Let there be life!-, and the discussion is about naturalism vs creationism, and whether going after abiogensis is a fair tactic.

If a natural explanation for abiogenesis doesn't eventually emerge (if experiment after experiment can't account for it), it would be a major problem for evolution. The door to "intelligent design" would get wider and wider as the failed experiments pile up.

I think one of these days fairly soon, we'll probably have some plausible evidence-based account for how life began. If I were a creationist, though, I would attack the failure to explain abiogenesis as evidence for intelligent-guided abiogensis, and then jump from there to intelligent design.

However biopoeisis took place, the observable fact is that evolution (by natural selection, among other processes) is observed to happen. The TOE does not address biopoesis, primarily because it is a separate issue.

 

[Slowvehicle]

Again, you can define evolution to only mean, after abiogenesis, and define abiogenesis as something else, OR, you can look at the process in it's entirety and see that the steps getting to abiogenesis followed a similar process evolving amidst selection pressures that led to abiogenesis.

It's like arguing that fertilization is not part of the pregnancy.

No, it's like arguing that the development of a foetus conceived the ol'-fashioned way is a different process than a foetus conceived in utero or in vitiro by artificial insemination.

 

[Slowvehicle]

So let's say 200 years from now we still don't have a definitive account of abiogenesis, just a bunch of failed experiments and various theories without any consensus.

You don't think evolution theory would be harmed by this? I think it would catastrophic. Evolution is a theory that explains how life forms change over time. Of course it needs a plausible explanation of how life began in the first place. Otherwise, it's like what Skeptical Ginger said: You're trying to explain pregnancy without talking about fertilization.

There is no such thing as a "failed experiment"; only disproved hypotheses.

Evolution by natural selection (and other processes, such as sexual selection) is observed in the wild, in the lab, and in the fossil record.

Even though we do not (yet) know how the first sets of ilving things (the first ones to survive, at any rate) came to be.

 

[abaddon]

No, not really.

Life is a necessary condition for evolution by natural selection to happen. How the life got there is immaterial.

Yes. Evolution does not address origins. Evolution only concerns itself with what happens after life is already existent. It cares not a whit for origins.

Creationists/cranks always try to conflate the two. They have no choice.

 

[truethat]

Yes. Evolution does not address origins. Evolution only concerns itself with what happens after life is already existent. It cares not a whit for origins.

Creationists/cranks always try to conflate the two. They have no choice.

And they think it's a stroke of genius when they do. It's their "GOTCHA" in their mind.

Meanwhile if they are looking at guided creation and guided evolution they have yet to explain why deformities happen. So divinely inspired perfection goes haywire every day. And it's just fiiiiine.

 

[RecoveringYuppy]

Abiogenesis is a necessary condition for biological evolution to get started. It's a fair tactic in a debate to attack X by attacking the necessary conditions for X.

Yes, but there is no doubt life exists. (haven't read the thread, I hope this obvious point has already been made).

 

[Belz...]

Abiogenesis is a necessary condition for biological evolution to get started.

Yeah but evolution works the same regardless of whether the first life forms arose on Earth's primordial soup, or on another planet, or in a lab, or by magic. Abiogenesis is irrelevant to biological evolution.

 

[ThunderChunky]

What are you calling a "darwinian replicator"?

The current theory is RNA molecules were replicating before abiogenesis. Are you calling the first RNA molecule the first abiogenesis?

Are you saying selection pressures were not acting on those molecules?

A darwinian replicator would be a self replicating entity with heritable traits that are subject to variation. A lone RNA molecule could be a darwinian replicator, people have created some in the lab, but those require very specific substrates. AFAIK, there's no plausible prebiotic RNA replicator that has been discovered.

There are at least two main schools of thought on abiogenesis: the genes first and the metabolism first. Self replicating RNA would fit into the genes first school, as would certain protocell models that are probably more plausible. These would fit with an early darwinian replicator. But the metabolism first side of the field thinks biogeochemistry developed into primitive metabolisms that were captured by protolife before genes came into play. If there's no genes (or primitive equivalent) there cant be darwinian selection, it would have to be a different type of selection.

 

[jimbob]

Except that there are plenty of examples of evolution happening whilst being observed - Darwin's Finches, and the Long Term Evolution Experiment being two examples. We also have plenty of fossil and genetic evidence that doesn't require alien intervention.

It may not require it, but it doesn't rule it out either, and once you let legitimate speculation about aliens seep into abiogenesis, I think it will seep into evolution. Not on the micro side, but certainly on the macro.

This was also a deliberately ridiculous worst case. A realistic worst case is that we don't demonstrate how abiogenesis worked. We already have plausible candidates. These won't be undiscovered.

Yes, I picked the worst case scenario to make my point. I don't believe we'll hit an intellectual roadblock like that. But I guess it's possible.

One small correction - you picked a bad case, no more progress for 200-years. I picked the worst case as far as natural abiogenesis was concerned - unequivocal evidence that life on Earth had been created by an intelligent agent.

It depends on what you are arguing. Evidence for evolution once life started would not be harmed. Take the worst case - we find an alien laboratory with identifiable machinery to create an ancestor of all life on Earth. Would that harm the theory of Evolution? No, it would just indicate that life was instigated by an intelligent agent.

And it would lead to the natural question that, if in order for life to exist, alien intervention was required, was alien intervention also required to guide the evolution of life once it started? Once you go down the road of abiogenesis-caused-by-external-factors (either supernatural or not), it necessarily bleeds over into evolution. How could it not? How could you tell someone, "OK, maybe aliens had something to do with life starting here, but they had nothing to do with it after that!" Huh?

Argumenon put it more succinctly than I did:

Yeah but evolution works the same regardless of whether the first life forms arose on Earth's primordial soup, or on another planet, or in a lab, or by magic. Abiogenesis is irrelevant to biological evolution.

I would argue that whilst evolution doesn't require abiogenesis to work, abiogenesis requires evolution to work.

 

[annnnoid]

This is wrong. If you can't explain abiogenesis (and I'm assuming a failure of explanation that spans centuries of experiments), then you open the door for legitimate speculation that external factors were involved that caused abiogenesis. That doesn't entail the naturalistic account of evolution is wrong.

But once you open that door, and people are comfortable with the idea that some other external factor, (aliens or supernatural) was required to get life rolling, you'll be on very shaky ground explaining why evolution is immune to those same external factors. There will be a competing theory (guided evolution) that will be almost impossible to argue against.

The question isn't whether or not evolution happens. Quite obviously it happens. The question is how it happens. What, ultimately, causes it to happen? It becomes much easier to introduce external factors (metaphysical or otherwise) into that process (individually and / or collectively) if they can be credibly introduced into abiogenesis itself.

 

[jimbob]

The question isn't whether or not evolution happens. Quite obviously it happens. The question is how it happens. What, ultimately, causes it to happen? It becomes much easier to introduce external factors (metaphysical or otherwise) into that process (individually and / or collectively) if they can be credibly introduced into abiogenesis itself.

That is looking increasingly unlikely. To overturn or even challenge the evolutionary explanation for the origin of species, one would need to posit something that is undetectable in its operation. Magic in other words. There is sufficient evidence for evolution working at all levels for anything else to be an utter failure.

 

[Skeptic Ginger]

No, it's like arguing that the development of a foetus conceived the ol'-fashioned way is a different process than a foetus conceived in utero or in vitiro by artificial insemination.

Your analogy doesn't fit reality unless you are arguing for Intelligent Design or creation of the first life form via magical conception and thereby trying to separate abiogenesis out, as if those two hypotheses are still on the table, it would be just as much denial as arguing we didn't have enough supporting evidence for evolution theory.

 

[Skeptic Ginger]

Yes. Evolution does not address origins. Evolution only concerns itself with what happens after life is already existent. It cares not a whit for origins....

Again, this is merely one way to look at evolution.

If you were to find out the same processes, random mutation of molecules and selection pressures, went back further than you considered 'life', what then distinguishes life from non-life in terms of evolution theory?

 

[annnnoid]

That is looking increasingly unlikely. To overturn or even challenge the evolutionary explanation for the origin of species, one would need to posit something that is undetectable in its operation. Magic in other words. There is sufficient evidence for evolution working at all levels for anything else to be an utter failure.

Correct me if I'm wrong... but evolution merely establishes that this, led to this, which led to this, which led to this. It does not and cannot ultimately explain (just for example) what caused the beak of one bird to enlarge while that of another did not. Survival imperatives may explain why the fit survive, but it does not explain how the fit become fit in the first place. Thus...legitimately introducing some manner of 'inexplicable' factor into abiogenesis may quite credibly implicate evolution.

 

[Jrrarglblarg]

Correct me if I'm wrong... but evolution merely establishes that this, led to this, which led to this, which led to this. It does not and cannot ultimately explain (just for example) what caused the beak of one bird to enlarge while that of another did not. Survival imperatives may explain why the fit survive, but it does not explain how the fit become fit in the first place. Thus...legitimately introducing some manner of 'inexplicable' factor into abiogenesis may quite credibly implicate evolution.

Replication and transcription error in mitosis and meiosis. Look it up.

 

[Belz...]

I would argue that whilst evolution doesn't require abiogenesis to work, abiogenesis requires evolution to work.

I don't know. Life could have arisen but replication not be subject to copying errors.

 

[Skeptic Ginger]

Yeah but evolution works the same regardless of whether the first life forms arose on Earth's primordial soup, or on another planet, or in a lab, or by magic. Abiogenesis is irrelevant to biological evolution.

The location of abiogenesis isn't relevant to either abiogenesis or evolution theory except to discover the mechanism of abiogenesis.

But in a lab or by magic are failed hypotheses that need not be entertained in this debate. Even if you hypothesized we can't leave an ET lab out of the possibilities it wouldn't change anything given said ETs would have also evolved.

It is time to stop the nonsense of considering gods or other magical processes in these universe ponderings.

We have a good theory for how life progressed after it arose. Why does it make sense that some other process took place before that time?

I think some people have been saying abiogenesis was a separate thing for so long it's hard to take a step back and consider we need a new way to think about it. Something happened and life began. When the switch was thrown, did the process of random mutation and natural selection begin? Or did it just continue?