Evolution starting with a single bacterium

Because if they were designed to do it, they all would do it, not just some. Rrhain told you as much, already.

There's not a lot to articulate. The behavior of the organisms falsifies a hypothesis that they responded to the pathogen via innate metabolic capabilities, because if they had, they all would have done it, because (according to your hypothesis where mutation did not occur) the organisms are all clones of each other.Because only a few survived, we know it was because they weren't clones like the rest; because we know they weren't clones, we know that mutation occured. Again, what's to articulate? The only design hypothesis that is tenable is the hypothesis that the designer designed one inital orgainism, and all other organisms are its decendants through evolution. A hypothesis that the observed behavior of these bacteria is the result of a specific, non-mutative metabolic design is falsified by the fact that the vast majority of bacteria died. Nonsense. Selection is practically instant. The mutation in question almost certainly occured in the first phase of the experiment, where you grew the bacterial lawn, before you added the pathogen (along with a bazillion other mutations that, as it turned out, weren't selected for.)There's plenty of time for evolution to work, here. Hundreds of generations and millions of individuals.Like Ned said this isn't a Visitors topic. If you want to discuss further open a new topic.

Well, bacteria don't have sex. They do exchange some genetic elements, but in a world without mutation, they're not exchanging anything they don't already both have.So, if we reject mutation, we necessarily conclude that all these bacteria have exactly the same genetics.Since they don't, however, we conclude that mutation occured. And why wouldn't it? Reproduction is a chemical process, and it's not perfect. Mutation just means that reproduction wasn't perfect, and why would we expect it to be? Too early? We've been through this. No other option is coherent with the observation. They have that built-in, random mechanism of adaptation. It's called "mutation and natural selection." It's the mechanism the experiment proves exists, and it's the same mechanism that does the same thing in all other organisms.Why propose an additional, unknown, untestable mechanism when we already have one that explains it just as well? How would you determine the difference between your unknown mechanism and the evolutionary mechanism, since the results are exactly the same in every case? Right, the selection happens when we introduce the pathogen. The mutation happens before, when we're growing the lawn. What part of that confused you?Moreover, given that bacteria reproduce asexually, what makes you think that the mutation that confers immunity needs to happen any more than once? All the resistant bacteria might very well be the decendant of exactly one individual. So I see, but the problem is, you don't doubt my evidence or reasoning, you doubt the conclusion. That's the back-ass-wards way to think, and it's what prompted Sherlock Holmes to say "once you have eliminated the impossible, whatever remains, however improbable, must be the truth."I'm sure you find the theory of evolution improbable. The problem for you is that all other explanations turn out to be even more improbable, or outright impossible or otherwise incoherent with the evidence.Evolution by natural selection and random mutation is the obvious, and only, explanation for what happened in the dish, twice over.

What happened to messages 12 and 13?Oh, never mind, I guess they're back.This message has been edited by crashfrog, 06-10-2004 09:34 PM

If it happens, it'll always be inherited. Bacteria reproduce asexually, not sexually, so there's no sexual selection of traits. Why bother calculating the likelyhood? We know it happened. What on Earth would the likelyhood tell us that the actual experiment hasn't already? Well, it will be until you can think of a situation where evolution and the unknown mechanism you propose would give different results. As it stands now we've got evolution, and then we have your unknown mechanism, which operates exactly like evolution in every case involving bacteria, apparently. How are we supposed to tell the difference?Do you see the problem yet? On one hand, we can explain it with a mechanism we have observed in other situations. But you would have us believe that a mechanism that only exists in bacteria and only reacts in this situation - and when it does act, acts exactly the way evolution is expected to - is responsible.That's what I mean by "untestable." It means that you've defined the mechanism in such a way that it can never be distinguished from evolution by any test. The fact that you and I agree on all the evidence, and we agree that all the alternative explanations are wrong. It's just that when it comes to taking the next logical step - the only remaining explanation is the most likely - you refuse to go. Why would that be except that you don't like that conclusion? We have a good explanation. It's called "evolution by random mutation and natural selection." It involves mechanisms we can test and observe, and it's falsifiable. It's a good explanation by any scientific measure.

As far as I'm concerned, it proves it by being the only scientific explanation that isn't contradicted by the experiment and is consistent with observations of other forms of life. And I do. But scepticism doesn't mean you can't ever agree that something is the most likely explanation. By all means, keep asking questions. It's just that I wish you would ask ones that the experiment itself didn't answer for you, you know? Why, though? We know mutations happen. We know selection occurs. We know both of those occured in the experiment, because they always occur. We know that they have the capability to explain what happened in the experiment, so what's the hold-up? Why look farther when we've already got an explanation that works? What about this one isn't enough for you? If you can construct a falsifiable, scientific, alternate explanation, I'll consider it. But believe me when I tell you that evolution is accepted as the mechanism here because it's the most parsimonious and consistent explanation we know of.

What exactly do you think would fossilize?

Instead, why don't you take it as a question, as it was intended, and just answer it? Here, let's try again: Exactly what do you think would fossilize?

Don't play games.You tell me what parts of the organisms you're talking about could fossilize, and I'll tell you if we have any fossils like that. It's pretty simple.

The ones you're asking about. Duh!

Are you saying that there arent? Then why did you ask if there were any fossils of them?

Would there be? Exactly what part of these organisms would fossilize?Remember when I asked you that before?

You're right. It just means we have to look carefully for other kinds of evidence that might shed some light on these creatures.

Well, there aren't any passenger pigeon fossils, even though there were 3 billion of them in the US at one time. Not a one.I agree that it's pretty hard to determine anything about these organisms in the absence of the fossil record. But taking that as proof that they don't exist is ludicrous. We know they must have existed; their decendants - all life - are proof of that.

Bias? I don't know what you're talking about.Have you ever seen procaryotes arise spontaneously via any process, intelligent or otherwise? Neither have I. Ergo the reasonable conclusion is that procaryotes are themselves decended from other organisms.