Randomness in Evolution: Valid and Invalid Usage

[sol invictus]

I still believe that evolution by natural selection is random.

Thanks.

So according to mijo, smoke detectors are random.

That is obviously a ridiculous position to take. There is no point in conversing with you, since we clearly have no common ground for communication.

 

[sol invictus]

I asked: "are smoke detectors random?"

You answered:

You're not going to get a yes or no answer because it simply doesn't exist for the smoke detector or evolution by natural selection.

Then I asked: "is evolution random?"

You answered:

I still believe that evolution by natural selection is random.

Change your mind much?

I'm getting dizzy trying to keep track of the convulsions you're going through in your attempts to appear to be not wrong. You're like a fish out of water, flipping and flopping from one position to the next with each post.

 

[cyborg]

I'm getting dizzy trying to keep track of the convulsions you're going through in your attempts to appear to be not wrong. You're like a fish out of water, flipping and flopping from one position to the next with each post.

Mijo's position is random.

 

[Ichneumonwasp]

It seems that Bennett and Lenski were also discussing general trends:

Please, let's stop equivocating so much over word meanings and word choices. Ayala discussed the grand trends in evolution and used the word random in a very different sense, which he defined nicely. His 'generality' was the generality of evolution as a whole, making sweeping statements and his emphasis was on natural selection and not variability. Big picture.

Bennett and Lenski discussed a particular type of adaptation that can be used as a general survival strategy to deal with different conditions (thermal in this case) and examined it all in terms of trade-offs. Their emphasis was on variability, which is vitally important in understanding evolution and evolutionary theory. Little picture.


There is no contradiction between the two. They wrote their papers for different purposes with different emphases and necessarily discussed issues in different ways. One is an editorial piece, the other primary research. Where is the problem?

 

[mijopaalmc]

Thanks.

So according to mijo, smoke detectors are random.

That is obviously a ridiculous position to take. There is no point in conversing with you, since we clearly have no common ground for communication.

Nice straw man. I didn't say that at all. You are simply being a troll and putting words in my mouth.

 

[mijopaalmc]

I asked: "are smoke detectors random?"

You answered:

You're not going to get a yes or no answer because it simply doesn't exist for the smoke detector or evolution by natural selection.

Then I asked: "is evolution random?"

You answered:

I still believe that evolution by natural selection is random.

Change your mind much?

I'm getting dizzy trying to keep track of the convulsions you're going through in your attempts to appear to be not wrong. You're like a fish out of water, flipping and flopping from one position to the next with each post.

What don't you understand about random processes' leading to orderly result not meaning the processes themselves are non-random?

 

[mijopaalmc]

Please, let's stop equivocating so much over word meanings and word choices. Ayala discussed the grand trends in evolution and used the word random in a very different sense, which he defined nicely. His 'generality' was the generality of evolution as a whole, making sweeping statements and his emphasis was on natural selection and not variability. Big picture.

Bennett and Lenski discussed a particular type of adaptation that can be used as a general survival strategy to deal with different conditions (thermal in this case) and examined it all in terms of trade-offs. Their emphasis was on variability, which is vitally important in understanding evolution and evolutionary theory. Little picture.

You don't seem to understand that Bennett and Lenski have demonstrated that the specific survival strategies adopted by different populations cause very different variations in fitness. This happen despite the populations being identical at the time of separation and the subsequent environment in which the six replicate population evolved after their separation being identical.

There is no contradiction between the two. They wrote their papers for different purposes with different emphases and necessarily discussed issues in different ways. One is an editorial piece, the other primary research. Where is the problem?

The editorial does not reflect the facts that are borne out in the primary research.

 

[Ichneumonwasp]

You don't seem to understand that Bennett and Lenski have demonstrated that the specific survival strategies adopted by different populations cause very different variations in fitness. This happen despite the populations being identical at the time of separation and the subsequent environment in which the six replicate population evolved after their separation being identical.

Oh really. I don't understand it, hmm? OK, so let's examine that. I specifically stated that they were looking at differences involving varibability and the effect on survival. Hmmmm, how do I not understand it?

What they showed was simply that there are trade-offs that certain organisms assume. Some might be highly adapted for warm conditions and put all their energy into that. Others might be highly adapt to cold conditions. Others will trade off and not grow as rapidly in either of those conditions but will assume other characteristics that allow them to survive in both. Now, they did not see a direct correlation between growth at low temp and high temp in all lines interestingly enough. Some of the strains that grew well in cold also grew well in the hotter environment, though most of them tanked in the heat. But the bottom line is that they were examining survival primarily based on variability -- that is the entire focus of that paper, to examine the variability inherent in that bacteria even when strains are selected for cold environments (because environments in this world change). They did not use very extreme conditions -- they could have grown the initial strains at even lower temperatures (if they could have gotten any to survive that low of a temp) and then put them into 60 C environments. This shows how adaptable E. coli is. Ooh, news flash.

Cut out the BS, Mijo, and deal with the real issues. This is a minor paper examining a small little slice of the evolutionary landscape. Stop looking at the molecules and stop accusing people of not understanding what is written in plain English.

The editorial does not reflect the facts that are borne out in the primary research.

It's discussing a completely different set of issues (although it clearly discusses variability as well), not a localized scenario. How do you fail to understand that?

 

[articulett]

and the only time randomness is mentioned in the paper he quotes is "in respect to trade offs"-- they're not saying evolution is random... they are still focusing on the "mutation" aspect. Mijo is all too adept at extracting the meaning he wants out of the words that are... and pretending that it's everyone else who doesn't understand the article.

I am fairly adept at reading scientific articles and understanding them... I cannot understand Mijo... I think he has the most bizarre interpretation of articles that I've ever seen and they are designed to support his need to believe that it makes sense to call evolution random.

Nobody, but creationists are calling evolution random...

No peer reviewed article is calling evolution random-- but mijo can do all sorts of semantic gymnastics to convince himself that is what they are really saying... --and per his loose definition of random... I guess that could be conceivable.

 

[Ichneumonwasp]

and the only time randomness is mentioned in the paper he quotes is "in respect to trade offs"-- they're not saying evolution is random... they are still focusing on the "mutation" aspect. Mijo is all too adept at extracting the meaning he wants out of the words that are... and pretending that it's everyone else who doesn't understand the article.

I am fairly adept at reading scientific articles and understanding them... I cannot understand Mijo... I think he has the most bizarre interpretation of articles that I've ever seen and they are designed to support his need to believe that it makes sense to call evolution random.

Nobody, but creationists are calling evolution random...

No peer reviewed article is calling evolution random-- but mijo can do all sorts of semantic gymnastics to convince himself that is what they are really saying... --and per his loose definition of random... I guess that could be conceivable.

Yeah, I think you're right. I think it might be time for me to bow out of this whole fiasco once again since it's beginning to look like the same **** different chapter.

Heck, I'm just repeating arguments that Schneibster, Cyborg, and Myriad originated months ago (and you probably tried before they even got involved). It's almost like these arguments work to quarantine the virus for a while, but once the topic drifts the slightest bit, the virus escapes and re-infects the system.

ETA:

But, before I go, I just gotta say to Sol Invictus -- great job. That smoke detector gambit is superb. Wish I'da thunk of that.

 

[zosima]

So mijo, I guess you're not willing to try to at least accept a reasonable definition of random? Did you miss that post? Essentially you're conceding that your definition is completely unrealistic. So let me say this, you're not willing to budge even when your evidence is shown to be in exact contradiction to your conclusion, you've demonstrated you don't understand the math behind the claims, you're demonstrated you don't have even basic science competency, and obviously have no understanding of evolution in specific. Really all you know is that you're sure, no matter what anyone says, that evolution is random.

zosima-

The journal article referred to the in the article that jimbob posted does in fact give an excellent example of what those on this thread who argue that evolution is random mean when they use the word random. While there was a general trend toward increased fitness at the temperature for which the strains were adapted, the actual change in fitness for the adapted strains varied widely and, in two cases was not even statistically significant, even though each of the six replicate strains was adapted to the same environment. In other words, that the strains became better adapted to their environment is indisputable and shows the orderliness and in that people like to call "non-random", but how the strains adapted to their environment demonstrates the essential randomness of the specific adaptation.

First let me say, as I mentioned above, this is one article and even this one article is terribly misinterpreted. We already have the quotes of the scientist who actually performed the experiment disproving your claims, but I guess you think you can interpret the study better than he can? I would trust his opinion and expertise in the field over your lack thereof, but if we're going to be interpreting this guy's data for him its not difficult to show that you don't know what you're talking about.

You assert that there is some random variable in this experiment, but if you read the experimental methods you would realize that the are lineages constructed in such a way as to maximize phylogenetic dissimilarity between them. The whole point of this guy's study was that he wanted to show that populations with a very different distribution of genes in the gene pool will adapt in the same way to a similar situation. While his evidence wasn't 100% conclusive the fact that he showed convergence of solution is very interesting. Put in terms that you can understand, many different lineages converged on only two different solutions. Different starting points, similar finishing points. This certainly doesn't support your conclusion that this is random.

Bennet and Lenski explain in their experimental methods that they separated the lines and diluted by a ratio of 1:100 in every single step. By the author's own words. this technique ensures

they have not shared a common ancestor for 4,000 generations and are
therefore phylogenetically separated from each other by 8,000
generations.

They took the variability that preexisted in the strain and maximized it for 24 different strains and yet the end behavior only demonstrated a handful of different responses. There is nothing random about this.

This just created greater variation between the different lineages, so some had more cold strong/hot weak and fewer cold strong/hot strong, while others had fewer stong/weak and more strong/strong. If we assume they only changed the distribution of genes and didn't completely eliminate some then given sufficient time all the populations would consist of strong/strong.

That said, we should also note that this is nothing like the natural world where you would never have a 1:100 dilution every day and I would assert that this non natural dilution step is the only random step in the whole process. In each line when they selected the single part that they were going to dilute they indubitably selected a part with a different distribution of genes for each line.

Plus the study admits they did not identify which genes contributed, so your assumption that a random mutation showed up over the course of the study by some sort of random mutation is dead wrong.

LET ME BE PERFECTLY CLEAR VARIATION DOES NOT EQUAL RANDOMNESS

I mean seriously if we took your ancestors and sol's ancestors 2000 years from now, I'd be very surprised if sol's ancestors didn't demonstrate better higher reasoning skills...but I can see why you'd be motivated to say that this was just dumb luck. (dumb luck, get it,ha ha ha)

I not considering the individual, I am considering the fact that the variation in early generations will determine the bias in much later generations.

Cool great, no one is arguing that this variation isn't as a result of mutations that are indifferent to the point of mutation, but given evolutionary time scales all the mutations will occur equally. In terms of survival of the population, the percentage of the population with a given gene that survives will exactly match the probability that any individual with the gene will survive. Both of these are examples of the law of large numbers. My argument from magnitude guarantees that the law of large numbers will apply. Thus the population dynamics in any generation and over time is determinate. I'm getting the feeling that all you random evo folks don't understand the law of large numbers very well.

Um, you realize that is a number of tests, not one done over 18 years.

Of course, but it took him 18 years of experimentation to get the rather modest result he has now. Its not like I didn't address the huge number of generations or the billions of microbes. If this is the best you've got you're really grasping at straws. That said we're already been over how the author completely disagrees with you and exactly what the flaws are in any hamhanded attempt to reinterpret his data for him.

I'm not sure what you are refering to when you say "make the argument in individualistic terms." Actually I'm not sure what the paragraph is getting at.

If you use the population level of explanation the law of large numbers applies and the system behaves deterministically, even within any single generation. You seem to claim that since there is inheritance that this somehow invalidates the result, but this would only be true if we were talking about a single individual. Heredity would only invalidate the law of large numbers if there were some sort of lateral heredity between individuals within a single generation, but this is nonsense, heredity is only passed down generations. This means that each generation is completely determined by the distribution of genes in the previous generation under influence of the environment. Do not conflate the complexity of prediction along large timescales with a random process, they are completely different.

No it doesn't, it mentions that among 18 different lines, 12 showed one pattern, and 6 showed another. Do they need the word in there explicitly?

Yes, again variation does not mean random as much as you would like it to.

The term precise genetic change doesn't say anything about randomness or not. The fact that I can spot a deletion at location X, doesn't mean that the change is predictable.

Of course it does. A precise change is exactly the opposite of a random change. In the same way that you conflate randomness and prediction, now you conflate precision of change with identification of change.

Then look at the language you quote after that. "Evolution often[/n] follows the same path," and "we've found a lot of parallel changes." Not Evolution follows the same path, or we found only parallel changes.

Their statements directly contradict your own. Their claim of parallel evolution despite variation is actually a stronger statement than the one that I'm making, but the scientist's statement does strengthen my own.

Both statements were qualified.

Trying to claim the opposite of what a scientist claims because they had the integrity to qualify their statements is a classic woo behavior. At this point you might as well give up.

Now the words "often" and "a lot" does indicate that the probabilities are indeed skewed. In the experiment I outlined that skew was about 2:1. If you have been following my argument, you'll note I specifically discussed the accumulation of skewed probabilities over time. We are the accumulation of many, highly biased events.

To recap from above the billions of microbes means the law of large numbers applies to any specific generation(where heredity is not accumulated only; constant). The many generations means the law of large numbers applies across many generations.

Even though each change might have a most likely outcome, the odds of them all happening are incredibly small.

Again you conflate an unpredictable outcome with a random one.
It's true the numbers might not be exact, in one generation 101,546,734,634 microbes with a given phenotype might survive and in the next 101,546,734,635
might survive, but that is exactly the type of variation that does not accumulate. I challenge you to provide any natural scenario where the fate of an entire species is determined by a single probabilistic event.

The fact is the strains developed (at least) two different ways of dealing with the change. Some developed one protein that confered one characteristic, and others developped a different protein that confered a different characteristic. That is a perfect example of unpredictability of changes at the gene level manifesting as significant variation at the phenotype level.

Your mistake is to assume that these characteristics developed over the course of the experiment. All the experiment did was magnify variation(by diluting and splitting lines) then modify the distribution of genes in the lines(by applying hot and cold.) There is no reason to believe anything random occurred. There is a strong bias against believing this without evidence as well. The reason is that mutation is micro organisms occurs very very slowly. That is why life on earth is 4.5 billion years old, and Eukaryotic life is 1.2 billion years old.

No, I was hoping you would read that, and consider it in conjunction with my previous arguments and realise that the unpredictability, even with a 2:1 bias, might actually manifest as significant variation when looking at evolution of an ecosystem. I thought I had explained some of the properties of systems with memory (heredity) and how they differ from system without. Apparently not well enough.

I've already explained these mistakes, look above to understand why.

As for selective reading - how one gets from only a 2:1 bias after "thousands of generations" as you say, to evidence of non-randomness, I don't know.

You seem to imply the thousands of generations is small. When they say "generation" they mean a serial dilution generation, this is not the same as saying "I'm a 3rd generation immigrant." This means they take a random subset of the culture,dilute the medium, then regrow it until the population consumes all resources. So this is many many many generations. How could they possible know precisely how many replications a microbe goes through? If you had read carefully you could have inferred this from the fact that they use exact numbers. They explain the process in their experimental methods.

So,okey dokey, if you still think I'm making this up and the scientist who wrote the study is misinterpreting his evidence, I challenge you to answer my question.
Name a scenario whereby the fate of an entire species is dependent on a probabilistic event.

 

[zosima]

It is also interesting to not that the Bennett and Lenski article was published in the very same PNAS issue from which articulett draws the Ayala article that says "evolution is not random". Their findings directly contradicts Ayala's statements.

Read my response=> You don't know what you are talking about. The reason the reviewers in the field didn't see a problem with this is because they are not saying inconsistent things.

 

[sol invictus]

Nice straw man. I didn't say that at all. You are simply being a troll and putting words in my mouth.

If you're NOT saying that (which I can't tell, since you flipflop and change your position randomly with each post), and you ARE saying evolution is random, your position is even more ludicrous than it already was.

If that's possible.

 

[mijopaalmc]

If you're NOT saying that (which I can't tell, since you flipflop and change your position randomly with each post), and you ARE saying evolution is random, your position is even more ludicrous than it already was.

If that's possible.

Evolution by natural selection is an orderly process that arises out of the random events of mutation and natural selection. There is nothing non-random about these events, but many repetitions lead tot he emergence of a pattern.

This is what I have always said about evolution by natural selection.

What is so hard to understand about that?

 

[zosima]

Evolution by natural selection is an orderly process that arises out of the random events of mutation and natural selection. There is nothing non-random about these events, but many repetitions lead tot he emergence of a pattern.

This is what I have always said about evolution by natural selection.

What is so hard to understand about that?

I'm absolutely convinced that is as good as things will get. At least we've learned something.

At any rate, I'm going to take a break from this thread for a while(maybe it will just die).

If anyone has any other questions, I'm sure they can just play choose their own adventure with the available supply of posts.



p.s. Mijo as much as I think you're missing something fundamental, I apologize if I stepped over any lines with any ad hominems.

 

[Belz...]

The article I just citd demostrates that evolution by natural selection is random in the way that I have defined it and that it does occur.

Of course, since the way you define it makes everything random, presumably unless there is only one possible outcome. This makes pretty much everything random, still.

Again, evolution can occur even without natural selection, in other words, if it is "random" as in "equiprobable".

I didn't mention selection. If evolution was "random", then there'd be no direction to it. How could you call it "evolution", then, since there'd be no way to distinguish how things change over time ?

 

[Belz...]

Nice straw man. I didn't say that at all. You are simply being a troll and putting words in my mouth.

Or maybe you simply don't understand the implication of your words.

 

[Belz...]

Evolution by natural selection is an orderly process that arises out of the random events of mutation and natural selection. There is nothing non-random about these events, but many repetitions lead tot he emergence of a pattern.

So you're saying that there is NOTHING non-random about selection ? Selection is random ?

That's odd, because environmental pressures DO seem to drive evolution in very definite directions.

 

[Paul C. Anagnostopoulos]

You most certainly did. Perhaps you should go back read more of my posts, starting with these:

I read those posts. I agree that evolution is a stochastic process. What I said was that I don't remember seeing your full description of evolution, so that we can tell what the hell you're on about.

You know, Mijo, when we say we don't understand what you're on about, it's because we don't understand.

~~ Paul

 

[Paul C. Anagnostopoulos]

Articulett, your selection they you mention is self referential. Winners are those who are selected, losers those who are culled. What's more evolution would occur without selection. If every organism reproduced, there would still be evolution. Organisms of this generation would be very different from the originals, because any mutation was "accepted". If you don't understand that then you don't understand the role of natural selection in the process.

If every organism reproduced ... statistically equally? I can't conceive of what the world would be like in that situation, but I'm not sure you would call it evolution.

~~ Paul