Randomness in Evolution: Valid and Invalid Usage

[Vorticity]

In essence, my answer to your question is "it depends on the context", which, while not the most satisfying answer, is the most straight-forward answer I can give.

And this is the essence of these arguments.

Recall that this whole thing started way back when Richard Dawkins asserted that "Evolution is the exact opposite of random." Really? The exact opposite of random? There's nothing less random than evolution? Really?

 

[sol invictus]

Your assertion "that eventually, all bacteria in that petri dish - and therefore eventually, in all petri dishes - should have the ability to metabolize citrate" is unfalsifiable, because you can always claim that we simply haven't waited long enough.

So freaking what? If you're asserting that evolution as a theory isn't falsifiable, you're just as wrong there as you are here, but that's another topic entirely. If you're asserting that this particular specific prediction isn't falsifiable because you might have to wait a long time, again, so freaking what? It was confirmed.

The crucial thing that you are seemingly ignoring is that it take an infinite amount of time for you to be certain that all the cultures will have evolved the cit+ phenotype. Thus, in any finite universe and for any finite experiment, there is a non-zero probability that you will observe at least one of the cultures will not have evolved the cit+ phenotype. This is, of course, perfectly consistent with evolution being a random (stochastic) process and completely inconsistent with evolution being a non-random (deterministic) process.

The same is true of every experiment ever performed, and every experiment that will ever be performed. That's the nature of science itself, everything is like that.

As to your obsession with smoke detectors, it may be absurd to assert that "it is random that smoke detectors go off when smoke pours into a room" without further explanation. It is perfectly acceptable, and possibly preferable, to make such a statement if you wanted explore why, for instance, americium-241 is used instead a nucleide with a longer half-life (e.g., uranium-238). Such an explanation may not be appropriate for a "how things work" talk on smoke detectors at a science museum, but it maybe perfectly suited for a lecture on the non-medical applications of radioactive decay in an advanced undergraduate engineering seminar. In essence, my answer to your question is "it depends on the context", which, while not the most satisfying answer, is the most straight-forward answer I can give.

Congratulations, we have a loser. You've chosen option c):

c) you argue that neither statement suffices because smoke detectors have both random and non-random elements, in which case it is crushingly obvious to everyone that the same applies to the vastly more varied and complicated phenomenon of evolution.

 

[mike3]

Any more blind assertions?

Would you care to elaborate on your totally unscientific statement?

Although the really disquieting the terminological debate about is that it show how willing some scientists and science popularizers are to commit the same abuses that creationists do, while deceiving themselves that they are actually helping.

The problem is that the term "random" would seem to "vindicate" or "fuel" criticisms of evolution that criticize it by attacking this "randomness". But I tend to think what many nonscientist evolution critics really mean by the term "random" is "atheist", or more specifically that "God has nothing to do with it", even though of course the theory of evolution is a theory of physics not meta-physics or religion(*), and so it simply doesn't say anything about God having anything to do with it, either confirmation or denial, in the same way as the theory of gravity doesn't say such things. People accept the theory of gravity, yet they don't accept the theory of evolution as much, interesting... (and I'm using that "theory" moniker on both to show that it _doesn't_ mean "unproven guess" in science. That is the colloquial use of the term, not the scientific one. And since it's the scientists who came up with the term "theory of evolution", the scientific usage is the correct one for interpreting that term correctly.) If anything, Gravity is more mysterious than Evolution! We have a good mechanism for the latter but the theory on the former still doesn't give us a mechanism! (And I don't think "string theory" is the right route since there seems to be no good way to test it.)

This I don't get:

NEWTON vs DARWIN.

NEWTON is a household name for his science.
DARWIN is a blasphemer for his science.

WTF? It's science, silly!

(*) YES, I know evolution does not belong to the formal scientific field of physics, but here I mean "physics" in a more general sense as "dealing with the physical world", in contrast to religion and meta-physics and other philosophical areas that deal with "transcendental" questions (e.g. does God exist, does life after death exist, what's the "meaning", if any, to life or existence, etc.).

 

[sol invictus]

Even if it were the case that eventually, all petri dish populations develop the ability to metabolize citrate (which would not surprise me), this would in no way prevent evolution from being a random process by the technical definition of the term. Given any stochastic process, you can almost always apply a filter to its random output that yields non-random results.

(See my previous response in this thread which touches upon this issue.)

sol is applying a filter to the output of the "petri dish evolution" stochastic process. Specifically, he's applying the "Does every petri dish develop the ability to metabolize citrate" filter. This may very well yield a non-random result ("Yes"). The fact that this particular filter yields a predictable outcome in no way implies that the original, unfiltered process is non-random. One could just as easily apply the "On which generation does the first dish develop the ability to metabolize citrate?" filter. Is there any doubt that the output of such a filter is a profoundly random variable?

There is more to the definition of what constitutes a random process than just what the long term trend or outcome is, even if that particular final state happens to be non-random.

I refuse to argue over semantics, it is a miserable waste of time. Kill it with fire.

But I will say that I think you are incorrect that most people with training in mathematics would agree with you, that I certainly constitute a counterexample, and you are also incorrect about the "mathematical definition". "Random" is almost never defined, and when it is, the definition doesn't correspond to the one you have in mind ("random variable" might be, but that's something else). I know - I wasted my time and looked in several probability and stats textbooks, as well as at other sources.

When I posted the definitions I found mijo ran away, and he never posted any source that supported his (absurd and idiosyncratic) definition.

 

[mijopaalmc]

Your assertion "that eventually, all bacteria in that petri dish - and therefore eventually, in all petri dishes - should have the ability to metabolize citrate" is unfalsifiable, because you can always claim that we simply haven't waited long enough.

So freaking what?

If a statement is unfalsifiable, then it is not scientific.

If you're asserting that evolution as a theory isn't falsifiable, you're just as wrong there as you are here, but that's another topic entirely.

Where did you ever get the idea that I was "asserting" that evolution was unfalsifiable?

Your statement "that eventually, all bacteria in that petri dish - and therefore eventually, in all petri dishes - should have the ability to metabolize citrate" because there is no empirical observation that can possibly falsify it, at least if you want results in finite time.

If you're asserting that this particular specific prediction isn't falsifiable, again, so freaking what? It was confirmed.

If a statement is unfalsifiable, it cannot be confirmed.

Aside from the impossibility of confirming an unfalsifiable statement, the statement "that eventually, all bacteria in that petri dish - and therefore eventually, in all petri dishes - should have the ability to metabolize citrate" was not confirmed. As you will recall, only one culture evolved the cit+ phenotype. You have yet to justify your leap from that single culture to "all bacteria in that petri dish - and therefore eventually, in all petri dishes ".

The crucial thing that you are seemingly ignoring is that it take an infinite amount of time for you to be certain that all the cultures will have evolved the cit+ phenotype. Thus, in any finite universe and for any finite experiment, there is a non-zero probability that you will observe at least one of the cultures will not have evolved the cit+ phenotype. This is, of course, perfectly consistent with evolution being a random (stochastic) process and completely inconsistent with evolution being a non-random (deterministic) process.

The same is true of every experiment ever performed, and every experiment that will ever be performed. That's the nature of science itself, everything is like that.

To cop a phrase from you:

So freaking what?

As to your obsession with smoke detectors, it may be absurd to assert that "it is random that smoke detectors go off when smoke pours into a room" without further explanation. It is perfectly acceptable, and possibly preferable, to make such a statement if you wanted explore why, for instance, americium-241 is used instead a nucleide with a longer half-life (e.g., uranium-238). Such an explanation may not be appropriate for a "how things work" talk on smoke detectors at a science museum, but it maybe perfectly suited for a lecture on the non-medical applications of radioactive decay in an advanced undergraduate engineering seminar. In essence, my answer to your question is "it depends on the context", which, while not the most satisfying answer, is the most straight-forward answer I can give.

You're chosen option c):

c) you argue that neither statement suffices because smoke detectors have both random and non-random elements, in which case it is crushingly obvious to everyone that the same applies to the vastly more varied and complicated phenomenon of evolution.

Uh...no!

As far as I have argued there are no non-random (deterministic) elements in evolution, and, even if there were, having a random (stochastic) element makes the whole process random (stochastic).

 

[sol invictus]

If a statement is unfalsifiable, then it is not scientific.

Nonsense. If a theory is unfalsifiable it is unscientific. The same obviously does not apply to statements, because nearly all predictions made by any scientific theory you care to name are unfalsifiable.

Your statement "that eventually, all bacteria in that petri dish - and therefore eventually, in all petri dishes - should have the ability to metabolize citrate" because there is no empirical observation that can possibly falsify it, at least if you want results in finite time.

But there is an observation that can confirm it, and that's exactly what happened.

If a statement is unfalsifiable, it cannot be confirmed.

Utter nonsense. Laughable nonsense in fact, since we are in the process of discussing an explicit counterexample.

Statement: the bacteria in this petri dish will eventually mutate and fixate the ability to metabolize citrate.
Experimental Result: the bacteria in that petri dish mutate and fixate the ability to metabolize citrate.

Statement confirmed.

Uh...no!

Uh....yes!

 

[mijopaalmc]

Nonsense. If a theory is unfalsifiable it is unscientific. The same obviously does not apply to statements, because nearly all predictions made by any scientific theory you care to name are unfalsifiable.

Examples?

But there is an observation that can confirm it, and that's exactly what happened.

No, it didn't, at least it didn't confirm the state that you made in the post that you keep asking me if I read.

Utter nonsense. Laughable nonsense in fact, since we are in the process of discussing an explicit counterexample.

Statement: the bacteria in this petri dish will eventually mutate and fixate the ability to metabolize citrate.
Experimental Result: the bacteria in that petri dish mutate and fixate the ability to metabolize citrate.

Statement confirmed.

That's not the statement that you made.

You said:

More specifically, the theory predicts that eventually, all bacteria in that petri dish - and therefore eventually, in all petri dishes - should have the ability to metabolize citrate (modulo a few details, like that said ability doesn't come at a cost so significant it cancels out the benefit).

This statement (which you claim is a prediction of evolution) would have been confirmed had all of the colonies evolved the cit+ phenotype. Since only one did, the evidence from this experiment is insufficient to confirm what you claim evolution would predict.

Uh....yes!

No! Since I have said that I do not consider any of evolution's constituent processes to be non-random, how exactly does (3) apply?

 

[sol invictus]

Examples?

Nearly every statement in any scientific theory ever. For example, general relativity predicts that if the universe is homogeneous and isotropic, it will have one of three final fates. That's unfalsifiable - the universe is not homogeneous and isotropic, and two of those fates take infinite time.

This statement (which you claim is a prediction of evolution) would have been confirmed had all of the colonies evolved the cit+ phenotype. Since only one did, the evidence from this experiment is insufficient to confirm what you claim evolution would predict.

"Conversing" with you is an utter waste of time.

That statement is obviously confirmable by exactly the same reasoning - the experiment could have resulted in all 12 petri dishes fixating that trait.

Moreover, the statement that all 12 colonies will eventually fixate is only one of several closely related predictions the theory makes. I wouldn't have thought it necessary to spell out the rest to any sentient life-form, but I guess I was wrong. Here are some of them:

eventually, all bacteria in petri dish 1 should have the ability to metabolize citrate

eventually, all bacteria in petri dish 2 should have the ability to metabolize citrate

eventually, all bacteria in petri dish 3 should have the ability to metabolize citrate

eventually, all bacteria in petri dish 4 should have the ability to metabolize citrate

eventually, all bacteria in petri dish 5 should have the ability to metabolize citrate

eventually, all bacteria in petri dish 6 should have the ability to metabolize citrate

eventually, all bacteria in petri dish 7 should have the ability to metabolize citrate

eventually, all bacteria in petri dish 8 should have the ability to metabolize citrate

eventually, all bacteria in petri dish 9 should have the ability to metabolize citrate

eventually, all bacteria in petri dish 10 should have the ability to metabolize citrate

eventually, all bacteria in petri dish 11 should have the ability to metabolize citrate

eventually, all bacteria in petri dish 12 should have the ability to metabolize citrate

eventually, all bacteria in petri dishes 1 and 2 should have the ability to metabolize citrate

eventually, all bacteria in petri dishes 1 and 3 should have the ability to metabolize citrate

....

No! Since I have said that I do not consider any of evolution's constituent processes to be non-random, how exactly does (3) apply?

Kill it with fire. Now.

 

[Uncayimmy]

I'll repeat what I said long ago: if "random" is synonymous with "probabilistic", or if it simply means that some aspects of the process in question are not deterministic or cannot be predicted with 100% certainty, then it is random that smoke detectors go off when smoke pours into a room(most smoke detectors rely on the decay of radioactive atoms, which is about as truly "random" - at least by those definitions - as you can get).

I'm pretty sure that vast majority of people, including scientists, would agree that that statement is totally absurd. Since I'm not very interested in writing a dictionary entry (I'm interested in the science of evolution), I'd rather just avoid the term "random" entirely.

Here are some (very) old posts of mine on that:

Unfortunately, you can't avoid the term random. Unfortunately, language evolved to where words have multiple meanings. Unfortunately, if you're going to discuss things like this with non-scientists on public discussion boards, you're going to have to find a way to deal with it without getting your panties in a bunch.

All you're doing is setting up a scenario where the contextual meaning of the word matches what you want it to mean while arguing that the other guy is wrong for doing the same thing. We could make a daily game show out of doing this with words in the dictionary that have more than one definition. Hell, we could do with some words that have only one definition listed.

But, hey, if you want to ignore my attempt at checking for understanding to rant about your love-hate relationship with the word random, go for it.

 

[Wowbagger]

I'm not going to get into the argument again, except to note my (doubtless controversial) observation that, in these arguments, people (like myself) who have graduate or undergraduate level educations in probability theory and/or statistics (statisticians, mathematicians, mathematical physicists, etc) generally tend to agree that evolution is "random" by the mathematical definition of the word.

It depends on what definition of "random" you are using, and that was the original point of this thread!

It is perfectly valid to say that evolution is random, as long as you mean it in a way this really is applicable to evolution.

Examples of inapplicable usage includes "blind chance" and special appeals to quantum fluctuations. There are probably others.

If "stochastic" can be called "random" also seems to depend on how you view it.

I prefer to avoid using both "random" and "non-random", when describing evolution, to avoid these things. Mutations are functionally indifferent, natural selection is a fitness-based filtering process, and the whole process obviously has a lot of predictive power.

But, that still won't shut everyone up, I'll bet.

 

[sol invictus]

Unfortunately, you can't avoid the term random.

I can and do avoid using it in situations like this.

Unfortunately, language evolved to where words have multiple meanings. Unfortunately, if you're going to discuss things like this with non-scientists on public discussion boards, you're going to have to find a way to deal with it without getting your panties in a bunch.

I have no problem dealing with it under ordinary circumstances. But when a thread has gone on for two years, with some participants having been involved in the same debate in other threads and for for several years before that... something is deeply, deeply wrong.

All you're doing is setting up a scenario where the contextual meaning of the word matches what you want it to mean while arguing that the other guy is wrong for doing the same thing. We could make a daily game show out of doing this with words in the dictionary that have more than one definition. Hell, we could do with some words that have only one definition listed.

I have no idea what you're talking about.

But, hey, if you want to ignore my attempt at checking for understanding to rant about your love-hate relationship with the word random, go for it.

What you said in your previous post was more or less fine. It's fine to say that "evolution is random, meaning that..." and fill in the ... with examples, illustrations of how some things are predictable and some aren't, etc. - just as you did. What is not fine is to assert "evolution is random", full stop. That gives nearly everyone the wrong idea. And if you define "random" in the non-standard way mijo proposes, then you can immediately see that every process in the physical world is random - making the statement "evolution is random" true but tautological (i.e. logically implied by "evolution is a process in the physical world").

Words are labels for reality. Labels are really boring. We might as well argue over whose handwriting is a more accurate description of the world.

 

[Earthborn]

What is not fine is to assert "evolution is random", full stop. That gives nearly everyone the wrong idea.

Good thing no one appears to be doing that, then. The discussion started because some have argued that "evolution is the exact opposite of random" and that is just not true.

And if you define "random" in the non-standard way mijo proposes, then you can immediately see that every process in the physical world is random - making the statement "evolution is random" true but tautological (i.e. logically implied by "evolution is a process in the physical world").

Just because the term "random" may apply to all physical processes does not necessarily mean the term is tautological. A tautology is something that is true by definition, and can't be logically untrue. If scientists in the 19th century had discovered that at a deep fundamental level all physical processes were completely deterministic, it would have meant that all physical processes are non-random. Physical processes are not random by definition; they are likely random because we discovered them to be.

 

[sol invictus]

Good thing no one appears to be doing that, then.

Except those that are.

The discussion started because some have argued that "evolution is the exact opposite of random" and that is just not true.

It's as true as "evolution is random".

Just because the term "random" may apply to all physical processes does not necessarily mean the term is tautological. A tautology is something that is true by definition, and can't be logically untrue.

Evolution is a theory about processes that take place in the real world. So if your definition of "random" makes all such processes random, as mijo's does, then the statement is a tautology.

Why do I need to explain things like this? Why do I bother?

Physical processes are not random by definition

How can you possibly claim that? It obviously depends on your definition, and they are by mijo's definition. By a more sensible definition, we actually don't know - we certainly did not "discover" them to be as you wrongly assert. Quantum mechanics is probably deterministic... but that's another topic.

 

[Wowbagger]

Good thing no one appears to be doing that, then. The discussion started because some have argued that "evolution is the exact opposite of random" and that is just not true.

It depends on how you define "random". In many cases, it is perfectly valid to say that "evolution is the exact opposite of random".

For example: Natural Selection is an algorithm. Therefore, it is the exact opposite of completely random (as in dice-rolling) chance and "happy accidents".

 

[mijopaalmc]

And if you define "random" in the non-standard way mijo proposes, then you can immediately see that every process in the physical world is random - making the statement "evolution is random" true but tautological (i.e. logically implied by "evolution is a process in the physical world").

The bold is one of the most persistent and aggravating lies told by those who argue that evolution in non-random (right behind "no reputable scientist would say that evolution is a random process" and "mijopaalmc is saying 'evolution is random full stop").

As to the definition and usage of "random", its synonymy with "stochastic" and its application to evolutionary biology, the whole discussion is that it is pretty much a nonstarter, because the participants won't agree on the meaning of the terms being discussed. I have in the past granted that "random" can and (most often in nonacademic discourse) does mean "[o]f or relating to an event in which all outcomes are equally likely". There is ample evidence from many dictionaries (see: e.g., The American Heritage Dictionary, def. 3; Merriam-Webster Online, def. 2b; The Oxford English Dictionary, def. 1b). However, most dictionaries also list a definition or usage of "random" as "[o]f or relating to a type of circumstance or event that is described by a probability distribution" (see: e.g., The American Heritage Dictionary, def. 2; Merriam-Webster Online, defs. 2a; The Oxford English Dictionary, Special Uses). It is interesting to note that, with the exception of the The Oxford English Dictionary, the latter definition actually precedes the former, suggesting that it is the primary definition of "random", and the OED actually lists some "Special Uses" of "random" that contradict in general definition provided therein, implying that "random" does mean something more than "equiprobable". In fact, the latter definition coincides nicely with the definition of "stochastic" as "[ı]nvolving or containing a random variable or variables" and "[ı]nvolving chance or probability" (see: e.g., The American Heritage Dictionary, def. 2; Merriam-Webster Online, defs. 1 & 2; The Oxford English Dictionary, def. 2a).

The specialist literature presents a even more explicit case for the synonymy of "random" and "stochastic". There are many books and scholarly articles that use the phrases "random (or stochastic)" or "stochastic (or random)". The CRC Encyclopedia of Mathematics explicitly states, "Stochastic is synonymous with 'random'." The National Research Council similarly glosses "stochastic" in its guideline for teaching and research:


Inspired by biology: from molecules to materials to machines

Opposite of a deterministic process in probability theory. Instead of dealing only one possible "reality" for how a process might evolve under time (as is the case with the solution to an ordinary differential equation), in a stochastic or random process there is some indeterminacy in its future evolution described by a probability distribution. This means that even if the initial condition (or starting point) is known, there are many possibilities the process might go to, but some paths are more probable and others less.

Bio 2010: transforming undergraduate education for future research biologists

In a stochastic process,individual outcomes cannot be predicted with certainty. Rather, they are determined randomly according to a probability distribution that arises from the underlying mechanisms of the process.

Finally, there are number of evolutionary biologists who explicitly state that natural selection is a stochastic process:

Selection: The Mechanism of Evolution

In every generation better-adapted individuals will bee more likely to survive and reproduce. This is only a tendency, however, not a deterministic rule. A snail living in an English hedgerow is less likely to be eaten of its shell is striped rather than plain.But it is not very likely to survive in any case; it may be eaten by a shrew, or die of heatstroke or starvation; it may even be eaten by a bird after all. Selection is a process of sampling. The variation of characters among individuals ensures that the sample that reproduces is a biased sample of the population as a whole, but its composition cannot be precisely specified in advance. But there is nobody responsible for selecting snail at the bottom of hedgerow, and no individuals, no matter how well-endowed has any guarantee of success, only a greater or lesser chance. Richard Lewontin once prefaced a lecture on this topic with a quote from Ecclesiastes: the race is not alway to the swift, nor the battle to the strong; but time and chance happen to both.


The nature of evolution as sampling implies that evolution is a stochastic process that is subject to sampling error. The composition of a population at any point in time will be determined by three factors. One is historical, the composition of the generation from which it descends. The second is selection, which tends to increase some kinds of individual and decrease others. The third is chance. The actual composition of the population will inevitably differ from what we expected based on descent and selection, because the life of each individual is a historically unique succession of events who eventual outcome is influenced by a multitude of factors. The next generation is formed in a stochastic, or probabilistic, fashion from the success and failure of many such lives. We may be able to predict its average properties with some assurance, but its composition will fluctuate to a greater or lesser extent in ways we cannot predict or account for.

Toward a New Philosophy of Biology: Observations of an Evolutionist

Selection is often described as a deterministic process, indeed sometimes even as a teleological process, because it seems to result in long-term evolutionary trends. These designations are, however, quite misleading. First of all, a close analysis of long-term evolutionary trends has shown almost invariably that they are actually quite irregular and often even terminated by reversals. Also, how could a process be deterministic in which there is no actual continuity because the genes of a population are returned in each generation to the common gene pool, and are thoroughly reassembled, with an entirely new start being made through the random production of new zygotes.

The importance of chance during evolution has been stressed by certain authors for more than 100 years (Mayr 1963:204). As early as 1871 Gulick insisted that the differences among snail populations on Oahu Island in the Hawaiian Islands were due to random variation and not to selection. Since that time no one has stressed the role of chance factors more emphatically than Sewall Wright. Chance operates at every level of the process of reproduction, from crossing-over to the survival of newly formed zygotes (Mayr 1962). This includes the locus at which mutations occur, the location of chiasmata involved in crossing-over, the segregation of chromosomes during the reduction the survival of the millions or billions of gametes, the meeting of two gametes of opposite sex prior to fertilization, and finally the untold interactions of a zygote with its environment (in the widest sense of the word). There is also genetic drift in all of its forms, particularly significant in small populations, and all the effects of linkage. There is also genetic drift in all of its forms, particularly significant in small populations, and all the effects of linkage. (Beatty 1984; 1987). Chance is also introduced by the phenomenon of pleiotropy. If a gene has multiple expressions, it will be selected for the most important of these,and other expressions of the gene will be carried along incidentally.

The large number of stochastic processes in populations of finite size, as well as the constraints which operate during selection, prevent selection from prevent selection from ever being a deterministic process. Rather, it must be remembered at all times that selection is probabilistic. This is true even for the success of the zygote. Each individual encounters in its environment numerous unpredictable adverse forces, such as catastrophes, epidemics, and unexpected encounters with enemies in which the outcome is largely probabilistic.

Finally, survival may depend on aspects of population structure. A certain genotype may have a high survival probability in a small founder population, while it is clearly inferior in a very large, widespread population.

It should be evident from this discussion how misleading the picture of natural selection is which some authors have. A careful reading of Darwin's version shows that his concept of natural selection was far more mature than that of most of his opponents.

Nevertheless, even he did not fully appreciate the power of the constraints and of chance. The modern concept of natural selection has been rather essentialist-deterministic philosophers. And yet who could question that the study of natural selection is a legitimate component of science? A philosopher thus has three choices: he can close his eyes to the existence of natural selection, or he can claim that, lacking the attributes of the phenomena of inanimate nature, it has to be excluded from science, or, finally, he can revise his view of what science is and enlarge his vocabulary and inventory of principles. and enlarge his vocabulary and inventory of principles.

 

[Uncayimmy]

It depends on how you define "random". In many cases, it is perfectly valid to say that "evolution is the exact opposite of random".

For example: Natural Selection is an algorithm. Therefore, it is the exact opposite of completely random (as in dice-rolling) chance and "happy accidents".

So, what do programmers write to simulate dice rolls?

I think one of the downfalls of the Internet and especially discussion boards is that people faced with simple terms or phrases describing a body of knowledge for which hundreds of thousands of words are needed to fully explain will write literally hundreds of thousands of words as to why their particular simple terms or phrases are better than the other guy's. The obvious conclusion is that we need a new word.

 

[Wowbagger]

The bold is one of the most persistent and aggravating lies told by those who argue that evolution in non-random (right behind "no reputable scientist would say that evolution is a random process" and "mijopaalmc is saying 'evolution is random full stop").

Well, I for one, think your use of "random" has its uses. Perhaps even in describing some parts of evolution. Though, probably not the whole thing.

If "stochastic" is supposed to imply "non-predictable", then clearly the term does not match the entire process of Evolution via Natural Selection. Some parts and aspects of it might be more stochastic and/or unpredictable, than others. It depends on which part or aspect you are looking at.

Though, in the end, I suspect that thinking of Evolution in terms of "randomness" is not going to be terribly useful to evolutionary biologists. It might for statisticians who do not need to iron out any of the empirical details of the process. But, to the biology expert who is bent on unraveling as much as possible: The fewer random elements, the better.

 

[Wowbagger]

So, what do programmers write to simulate dice rolls?

In computers, it would be a simulation, not an actual dice roll. Although there is always work being done to try to introduce a "true random number generator" for computers, we do have to put up with pseudo-random numbers, for now.

The obvious conclusion is that we need a new word.

Evolution is... supercalafragalisticexpialadoshus!

 

[Uncayimmy]

In computers, it would be a simulation, not an actual dice roll. Although there is always work being done to try to introduce a "true random number generator" for computers, we do have to put up with pseudo-random numbers, for now.

You haven't seen my version. For each roll requested, it sends an e-mail back to me, and I roll the dice and respond accordingly. Games run a bit slowly, but randomness is assured.

 

[sol invictus]

<intellectually dishonest semantic polemics snipped>

This:

I agree that random is a slippery term that's best avoided. However, it seems to me that as far as processes are concerned, there is no logical room left after we include deterministic and random factors. That makes random a synonym for nondeterministic. Am I missing something?

Yes - the way the term "random" is used, it is not synonymous with "non-deterministic". "Random" often implies "flat distribution", "directionless", or "equiprobable". As one example, consider the lottery where the numbers are drawn from bouncing balls. Is that process "random"? Certainly most people would agree that it generates random numbers, and yet the process itself might be deterministic.

Another example is suggested by your dictionary definition. Consider a measurement in a physics experiment, say of the length of some object. The length is not precisely defined due to quantum fluctuations, and therefore the result of the measurement is, strictly speaking, non-deterministic. And of course in addition there are the usual types of measurement errors, which may or may not be deterministic.

And yet, no one in their right mind would say that the results of measuring something with a tape measure are "random". They might say the errors are random (even though they may be deterministic), but they would never say the result is. Why not? Because the result has a non-zero mean and small fluctuations around that mean. We don't usually characterize distributions like that, distributions that are fairly sharply peaked around some non-zero value, as "random".

I presume we agree that a stochastic process is one that has some random generators.

"Stochastic" is close to synonymous with non-deterministic, but carries a slightly different connotation. In physics it's often used for systems in which the non-deterministic element is some kind of noise, thermal or otherwise. More generally it usually implies the presence of some kind of direction, force, or tendency, one that is perturbed but not destroyed by the noise. I'd say it's the best term to describe evolution.