Randomness in Evolution: Valid and Invalid Usage

[mijopaalmc]

Are we done now?

Not really, because the terminology "non-random" is an inaccurate description of evolution by natural selection. The individual events of evolution are governed by probability, which over many repetitions leads to the orderly development of adaptations. In other words, its order proceeds directly from its randomness, not some underlying deterministic framework.

 

[zosima]

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. Mutation and natural selection (or radioactive decay) are both random because they operate on probabilities, but they lead to the ordrely adaptations that we see in evolution by natural selection (or the function of a smoke detector).

What is you're problem with that description?

I think thats probably as good as we're going to get and its pretty close to the initial claim "that we could replace random with indifferent". I would say I accept that description, although I would word it differently. And that we'll just have to agree to disagree on the more fundamental issues. I would hope we understand each other's arguments thoroughly, whether we agree or not.

What does everyone else think about that?

Not really, because the terminology "non-random" is an inaccurate description of evolution by natural selection. The individual events of evolution are governed by probability, which over many repetitions leads to the orderly development of adaptations. In other words, its order proceeds directly from its randomness, not some underlying deterministic framework.

[sarcasm]Yes,yes mijo all physical phenomena are random. All those silly people who thing otherwise are quantum tunneling through our seats right now.[/sarcasm]

It seems like this post is a step in the wrong direction...we may have passed our high point.

 

[articulett]

moreover, evolution proceeds whether there is "randomness" or not. You could tweak all the DNA on purpose... and we do... and let the environment select the winners-- evolution can occur without randomness... but it sure as hell can't occur without selection of the "winners" and the culling of the losers over time.

But Mijo disagrees with anything and every Dawkins says--he thinks he's smarter than him. He thinks he's smarter than you zosima. I suspect he is the only one with such an elevated opinion of his "description" of evolution.

 

[sol invictus]

Not really, because the terminology "non-random" is an inaccurate description of evolution by natural selection. The individual events of evolution are governed by probability, which over many repetitions leads to the orderly development of adaptations. In other words, its order proceeds directly from its randomness, not some underlying deterministic framework.

So you've changed your mind? You no longer believe that "evolution is random"?

You certainly insisted on it before.

That's OK - there's no shame in being wrong and changing your mind. On the contrary, really.

 

[mijopaalmc]

[sarcasm]Yes,yes mijo all physical phenomena are random. All those silly people who thing otherwise are quantum tunneling through our seats right now.[/sarcasm]

It seems like this post is a step in the wrong direction...we may have passed our high point.

Why do you insist on repeating this tired old straw man?

While we may not be able to directly test evolution by natural selection as a stochastic process by plugging in identical initial conditions, we should be able to make testable predictions about what we should observe if we assume that evolution by natural selection is a stochastic process as opposed to what we should observe if we assume that evolution by natural selection is a deterministic process given the empirical distribution of phenotypes within a population.

 

[mijopaalmc]

So you've changed your mind? You no longer believe that "evolution is random"?

You certainly insisted on it before.

That's OK - there's no shame in being wrong and changing your mind. On the contrary, really.

Where did I give you the impression that I no longer think evolution is random?

Just as the random decay of a radionucleide can lead to the orderly and predictable operation of an ionization smoke detector, the random events of mutation and natural selection can lead to the orderly and predictable adaptations observed in evolution by natural selection. However, orderly and predictable behavior is not "non-random", because it is simply based on probability.

Basically, I support the emphasis on the orderliness and predictability of evolution by natural selection but object to its inaccurate labeling as "non-random".

 

[Walter Wayne]

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.

All that is required for evolution to occur is a source of change. What Darwin and those who follow tell us, is why the evolution we see looks the way it does. The answer was descent with modification (heredity with mutation) and natural selection. Sure evolution proceeds whether the change is random or not. The question is, is it? And if it is, does natural selection "suppress" the random nature, to make it as reliable as, say, gas laws?

And since we are talking about valid uses in general, another question arises: Whether the change is random or not, is selection sufficiently complex and interlinked enough that the result is random in the various laymen's senses of the word.

Walt

 

[zosima]

moreover, evolution proceeds whether there is "randomness" or not. You could tweak all the DNA on purpose... and we do... and let the environment select the winners-- evolution can occur without randomness... but it sure as hell can't occur without selection of the "winners" and the culling of the losers over time.

But Mijo disagrees with anything and every Dawkins says--he thinks he's smarter than him. He thinks he's smarter than you zosima. I suspect he is the only one with such an elevated opinion of his "description" of evolution.

Okay, rather than agree to disagree, I guess we'll have to disagree to disagree.

I could really care less what Mijo thinks about me. Maybe Mijo does have evolution right and I've got it wrong but he certainly needs to work a whole lot on his set set theory.*

*I seriously doubt I'm ever gonna let that one go, its rare you catch someone in such a solid contradiction. ie A claims B by C's authority. A claims C really knows what they're talking about. Upon close inspection C claims ~B....Ouch!

Why do you insist on repeating this tired old straw man?

The reason I trot out the strawman, is because If I haven't been made it clear several times in the last couple of posts, I'm not taking this too seriously anymore and I was hoping we could reach some sort of impasse, but.....you just can't seem to quit. Okay...once more into the breach...

While we may not be able to directly test evolution by natural selection as a stochastic process by plugging in identical initial conditions, we should be able to make testable predictions about what we should observe if we assume that evolution by natural selection is a stochastic process as opposed to what we should observe if we assume that evolution by natural selection is a deterministic process given the empirical distribution of phenotypes within a population.

Like what testable predictions? I think part of the reason that people find your position so unreasonable is because it is completely untestable. You've stated that you believe that if a system that appears deterministic has any stochastic components that you consider the system to be random. You've stated(on the basis of a false premise) that even if a probability distribution has two values P(1) = 1, P(2) = 0 that you continue that to be a random system. So what test could I possibly perform? What observation could I possibly make? The only system that you could even name that was non-random by your definition was a theoretical system. A system that had only one outcome by virtue of the fact that you defined any outcome in that system to be the same outcome. You haven't given any example in the real world. So another reason the old strawman gets trotted out is because you are talking about the same sorts of marginal probabilities. Your definition of random was so broad that even if I'm as certain as I am that I'm not going to fall through my chair, your definition would still count the support of my chair as random.

So have you reconsidered your position? Can you name a real world example of a deterministic system? Otherwise your definitions are so restrictive that there is no sense in having a discussion.

 

[zosima]

I would agree this is the central question.

And if it is, does natural selection "suppress" the random nature, to make it as reliable as, say, gas laws?

The answer:
Yes.

There is no need to "suppress" the "random nature" in the same way that there is no need for a gas to "suppress" its "random nature". Populations and species are predictable like gases because the scales at which their characteristics change is much larger and slower than that of their constituents. Most species live at least hundreds of thousands of years, most individual creatures in a species live or die based upon decisions made on the order of minutes to seconds. Most species have between millions and billions of members, at their peak, yet the random elements are individuals or even the genes of these individuals. When you look comparative numbers there is no other way to see it.

Conservatively species work on a scale that is a billion times larger than their components(a high end estimate is probably more like 10^15, true its no 10^23....but when your numbers are that big does it really matter? )

 

[DeiRenDopa]

I'm not entirely clear about the details of your situation. Why is there drift? Why do you presuppose that the species must bifurcate in a single direction? What causes the bifurcation?

To be clear:
I've really been taking two different tacks in my previous post a sort of strong determinism, based on punctuated equilibrium, and a weaker one.

Weak:
I guess it would depend on what is causing the drift. I would argue that directed drift does not occur spontaneously. When people talk about mutations being indifferent, they're essentially saying that in absence of selection the gene pool drifts in all directions(ie the standard distribution of the gene pool increases to the limits allowed by the niche, but the median stays fixed.) So if you postulate that the median of the gene pool is shifting, then I would assert that this is either because some external cause made it possible for the species to enter a new niche and the species adjusting to a new equilibrium or that some external selective pressure has been applied to the species in its current niche and this is causing the species to adjust to the new pressure.

Strong(which assumes everything the weak position does):
Punctuated equilibrium suggests that as far as our evidence is concerned, we don't see drift, we see discrete changes. So one species, pivotal event, new species. This may be because drift never occurs or it may be because the scales of evolution and our evidence is so many orders of magnitude larger than the time scale of genetic drift that it is highly improbable that we'll see a smooth continuum of transitions. Either way, this sort of drift is not significant to the theory of evolution. All that needs to be considered is the characteristics of a species at ecological equilibrium, just like the macroscopic study of a gas.

.
Thanks for this zosima.

I really shouldn't have jumped in; there is a lot in the earlier posts you wrote in this thread, and for us to avoid talking past each other would take some time and patience.

Anyway, as the thread now seems to be about something quite different, I shall take my leave.

 

[Dancing David]

Ballistics.

You, like sol invictus, are relying on uncertainty in the initial conditions to declare that my definition is meaningless. However, my point is that, in the case of a stochastic process, each possible value in the distribution of initial condition yields at least two distinct outcome, not just one, as would be the case with a deterministic system.

Ballistics like what?

If we say that it is an imaginary shell travelling through imaginary space to hit an imaginary target. (I am not using imaginary to be a put down, I mean it in the sense of a 'math space' where reality is not modeled except in a very limited fashion.)

The same factors which say ballistics is deterministic but that outcomes are varied are the same things which say that evolution is deterministic but varied.

The trajectory of a shell is not an exact field, especially as the barrel gets worn.

Celestial mechanics gets even worse.

 

[Belz...]

An equally interesting question is why you continue to deny that the definition I give is not a real definition

Funny, it appears in several dictionary

So IS IT or IS IT NOT a real definition ???

Again, this show that you do not understand the definition that I have given. In order for a event to exist its opposite must also exist

?? It's opposite ?

Look, calling evolution "random" is a simple statement that you can't simply take a phenotype and say that an individual possessing it is guaranteed to reproduce.

And again this means that everything is random. Can't you understand your own words ?

 

[Belz...]

No, you didn't actually read what I wrote or what I referred to (which seems to be a huge problem with those who argue that evolution is non-random.

When you get to the point where you think that everybody who disagrees with you does so because they don't understand you, you might start considering that it is you who cannot communicate properly.

A sure event (e.g., hitting the dart board universe) is deterministic

Since when am I sure to hit the dart board, to say nothing about a specific point of it, when throwing darts at it ?

An almost sure event (e.g., hitting a specific point or line the dart board universe) is random, because strictly more than one outcome exists.

How is that "almost sure" ?

As zosima illustrated, you are arbitrarily ignoring possibilities in order to make your example deterministic, but it makes no sense to do so. A probability of 0 is still a probability. Now, if you want to argue that the probability needs to be non-zero, then do so.

 

[Belz...]

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.

Where did I give you the impression that I no longer think evolution is random?

 

[Dancing David]

Ichneumonwasp-

It is through the "living and dying" of the individuals within a population that evolution takes place. You have to understand how randomness gives rise to order in order to understand evolution.

Not really, living and dying is not the goal, reproction is, living long enough to reproduce is all it takes.

I am shocked you keep getting away from the, it is not surviavl of the fittest, it is continuation of the fit enough to reproduce. It is not living and dying, it is living enough to reproduce.

I am curious why, for someone who is so knowledable about evolution, you keep making those particular mis-statements of the theory of evoltion.

 

[Dancing David]

It seems like this post is a step in the wrong direction...we may have passed our high point.

Long, long ago in a galaxy far away.

 

[Ichneumonwasp]

Ichneumonwasp-

It is through the "living and dying" of the individuals within a population that evolution takes place. You have to understand how randomness gives rise to order in order to understand evolution.

Yes, that is what we've been trying to tell you. You keep asking us to show you the evidence that evolution is not random. That is the evidence. Evolution is an emergent property that arises from the random acts of living and dying in an incredibly complex system. Emergent properties are called 'emergent' because they differ from the individual properties of the underlying system. Evolution -- the emergent property -- is not-random because it doesn't make any sense to apply that term to it. It isn't random. It isn't non-random. "Random" and "chance" shouldn't even enter into discussion of the emergent property.

By the way macroscopic gas laws may be very good at describing the thermodynamics of a system but they are not do good at all for describing reaction kinetics. Thus, you can have a thermodynamically favorable reaction that takes place very slow and the microscopic gas laws will not explain the behavior of such a system very thoroughly. For such an explanation, you need to understand statistical mechanics, which does describe the partition of microstates in a gas by a probability distribution.

Of course, but that is not what the discussion concerns. You asked how anyone could call evolution non-random. We don't say that it is specifically non-random (again, neither term -- random/non-random properly applies), but that it simply is not random. When we describe the emergent property we should not apply these terms. We can easily apply them to the underlying processes that 'create' the emergent property, and they are useful at that level of description. No one claims that there is only one level of description, however. Random (or chaos) is quite a good word for describing the molecules that comprise a large volume of gas; and it is helpful in describing the struggle for existence. The mistake arises from applying the word 'evolution' to this lower level description -- the struggle for existence. The struggle for existence is a part of 'evolution' and part does not equal whole.

 

[Ichneumonwasp]

Not really, living and dying is not the goal, reproction is, living long enough to reproduce is all it takes.

I am shocked you keep getting away from the, it is not surviavl of the fittest, it is continuation of the fit enough to reproduce. It is not living and dying, it is living enough to reproduce.

I am curious why, for someone who is so knowledable about evolution, you keep making those particular mis-statements of the theory of evoltion.

DD, I introduced the term 'living and dying' for ease of discussion. We all know that what is really at stake is 's/he who leaves behind the most babies, who then leave behind the most babies", but it gets tiresome typing that over and over. I know that Mijo knows that -- he is not trying to slip one in on you as far as I can tell.

"Living and dying" should be understood as a proxy for ease of discussion only.

 

[Dancing David]

Not really, because the terminology "non-random" is an inaccurate description of evolution by natural selection. The individual events of evolution are governed by probability, which over many repetitions leads to the orderly development of adaptations. In other words, its order proceeds directly from its randomness, not some underlying deterministic framework.

How do you knwo that apparent order does not arise from deterministic processes?

Seriously. If the random gave rise to order, could it not be that variation gives rise to variation and that deterministc process, which effect an individual in a pseudo random fashion provide the constraint which creates the apparent order?

Take the Brownian motion of ions in a inter cellular fluid, the motion of the ions is randomly based, yet the function of an ion channel is deterministic.

Is it the random motion that creates the difference in ionization across the cell membrane or the deterministic function of the ion channel?

 

[sol invictus]

Where did I give you the impression that I no longer think evolution is random?

You just said so, mijo:

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.

Change your mind again?

You see, you used to constantly repeat "evolution is random", and that's what started this whole stupid set of threads. Now you've gotten so twisted up in knots trying to avoid admitting you were wrong, that you've been reduced to saying "evolution is not non-random" - which I doubt anyone would bother to disagree with.