Randomness in Evolution: Valid and Invalid Usage

[jimbob]

URS, Sol Invictius, and Mijo, (and any one else too):

Forgetting the dictionary definitions for a while.

Firstly

Is there a random component to natural selection? If no, doesn't that mean that at birth the traits and the environment have already dictated which individual organisms will reproduce? I would say that the traits modulate the probability of reproduction, ("loading the dice"), but don't determine it as random events like weather would affect survival and reproduction.

Secondly

Don't the other organisms in the ecosystem also affect the fitness landscape for the remaining organisms? And doesn't this mean that (in any generation slight) mutations affect the fitness landscape? Over time, doesn't this mean that the fitness landscape is itself subject to change random change?

The effect would be when the environment is already changing and evolution is fastest, when the "shape" of the ecosystem is most fluid.

Thirdly

Was there any inevitibity about the emergence of humanity, or a similar organism

a) At the time of the KT impact?

b) At the time of our last common ancestor with chimps?

Fourthly

If not, then isn't it reasonable to talk about evolution being random? Especailly if talking to people who do think humanity is somehow special?

 

[CFLarsen]

Wrong. It is more like "evolution is a stochastic process, full stop" is the correct statement.

Notice how you start talking about evolution, then by the end you are talking about selection. You know evolution is more than just selection, right? (hint: the "more than" is the random stuff).

Once again, you try to turn the argument upside down. You want it to look as if randomness is the guiding factor in evolution and not selection, when it's the other way around.

Your argument is basically this:

Pick out the aces in a deck of cards.
Select one of them.
Say: "Yes, it was a club this time, but look, it was an ace! And aces win, always!"​

It should go like this:

Shuffle the deck.
Pick hands.
The hand than works the best, according to the rules at the present, wins.​

You know what you are doing, and that you are doing it wrong. You stack the deck, and decide what the outcome must be.

 

[Reality Check]

URS, Sol Invictius, and Mijo, (and any one else too):

Forgetting the dictionary definitions for a while.

Firstly

Is there a random component to natural selection? If no, doesn't that mean that at birth the traits and the environment have already dictated which individual organisms will reproduce? I would say that the traits modulate the probability of reproduction, ("loading the dice"), but don't determine it as random events like weather would affect survival and reproduction.

There is a "random" component to natural selection on the individual level since mutations, genetic diversity and the environment determine which individuals are more likely to survive and reproduce.
The population as a whole reacts deterministically to natural selection, i.e. to fit the environment. Look at the example of antibiotic resistance in the Wikipedia article. Another good example is the evolution of the peppered moth. This is essentially cause and effect - the trees get darker and so the moths get darker, the trees get lighter so the moths get lighter.

Secondly

Don't the other organisms in the ecosystem also affect the fitness landscape for the remaining organisms? And doesn't this mean that (in any generation slight) mutations affect the fitness landscape? Over time, doesn't this mean that the fitness landscape is itself subject to change random change?

The effect would be when the environment is already changing and evolution is fastest, when the "shape" of the ecosystem is most fluid.

The environment does include other organisms, e.g. predators. The predator/prey feedback loop (evolutionary arms race) is a well known process. The most dramatic change in the fitness landscape caused by evolution was cyanobacteria evolving oxygenic photosynthesis and so largely transforming the Earth's atmosphere.
Thus the answer is that evolution does change the fitness landscape and vice versa in a deterministic manner.

Thirdly

Was there any inevitability about the emergence of humanity, or a similar organism

a) At the time of the KT impact?

b) At the time of our last common ancestor with chimps?

The emergence of humanity, or a similar organism has never been inevitable. There is no reason why another KT impact could not have happened a couple of million years ago and so made this whole topic moot.

Fourthly

If not, then isn't it reasonable to talk about evolution being random? Especially if talking to people who do think humanity is somehow special?

When we look at the ancestral tree of humanity we see many side-branches that came to sudden ends. It would be just as likely for a Neanderthal to be sitting here wondering about what happened to Cro-Magnons as the reverse situation. This does not make humanity special - we just happened to be the branch of the tree that survived.
We should not change the language of science to fit the preconceptions of anyone.

One article I suggest everyone read is TalkOrigin's "Evolution and Chance" (10 years old but still relevant). A pertinent sentence is:

There is no basic randomness here, except as far as it arises from the general indeterminacy of the physical world (known as stochastic processes).

 

[sol invictus]

If not, then isn't it reasonable to talk about evolution being random? Especailly if talking to people who do think humanity is somehow special?

The fact that evolution has random and unpredictable aspects (such as the existence of humans) does not make the whole process random.

If you light a fire, do you consider it random that heat will come from it?

Do you agree with the statement "fire is random"?

 

[MG1962]

Thirdly

Was there any inevitibity about the emergence of humanity, or a similar organism

a) At the time of the KT impact?

b) At the time of our last common ancestor with chimps?

Fourthly

If not, then isn't it reasonable to talk about evolution being random? Especailly if talking to people who do think humanity is somehow special?

Well with hindsight we can say the KT impact influenced the emergence of intelligence. Wether we could have predicted it at the time, I dont know. Dinosauria was not up to the challenge. 300 million years or so, and they really never seemed to have taken that step

In general mammals seem pre-disposed to intelligence, if not man, then something would have come along. Humanity is only special because we are an egotistical creature by nature - maybe that's part of self awarness. Remember there is real evidence that Neanderthal Man was also self aware, maybe he thought he was special in some way before we kinda wiped him out

 

[Belz...]

It's not a minor point when people get seemingly incensed at me for engaging in a "semantic argument" when I argue that evolution is mathematically random but then they insist they didn't say "random means acausal" based on a sematic argument.

Evolution is not "random" by any meaning of the word unless you can show that quantum fluctuations have any effect on it. Some part of it are "probabilistic" because we don't know the outcome from the start, but that doesn't make evolution random.

 

[MG1962]

Evolution is not "random" by any meaning of the word unless you can show that quantum fluctuations have any effect on it. Some part of it are "probabilistic" because we don't know the outcome from the start, but that doesn't make evolution random.

I think we need an Albert Einstein of evolution to come along and put some order into what we are seeing. From out current perspective there is great randomness in the events of evolution. From other scientific endevours we see randomness is our lack of understanding, rather than there being a genuine lack of pattern

 

[Dancing David]

Taffer!

BTW, thank you very much, you have enlightened me in correct thinking again.

 

[Belz...]

No it doesn't. If you bothered to actually examine what the mathematical definitions of "random" and "deterministic", you would see that "random" means that identical initial condition don't always yield identical final conditions, whereas "deterministic" means that identical initial condition always yield identical final conditions.

Which makes evolution deterministic.

 

[Dancing David]

You are the one who is equivocating. Long-term orderly behaviors, such as the adaptive patterns we see in evolution by natural selection, does not imply a non-random process. Even if evolution was random in the sense of being equiprobable for all phenotypes, population would still evolve by regression to the mean.

Hi Mijo, I am sorry that one just shot past me, what are you trying to say.

Evolution occurs because of reproductive success in different enviroments. What are you sying about reggression to the mean? The distribution of phenotypes in contingent upon history.

 

[Dancing David]

Well with hindsight we can say the KT impact influenced the emergence of intelligence. Wether we could have predicted it at the time, I dont know. Dinosauria was not up to the challenge. 300 million years or so, and they really never seemed to have taken that step

Um, there seems to be some thinkuing that is innappropriate to apply to the biological process of 'evolution'. You have not demonstrated that dinosaurs did not possess intelligence. The KT impact is part of contingent history but to say that li led to intelligence in humans is rather a far stretch.

In general mammals seem pre-disposed to intelligence, if not man, then something would have come along. Humanity is only special because we are an egotistical creature by nature - maybe that's part of self awarness. Remember there is real evidence that Neanderthal Man was also self aware, maybe he thought he was special in some way before we kinda wiped him out

Um, more assertion without evidence, homo sap sapiens 'wiped' out homo sap neanderthal? Any evidence of that?

Do coyotes wipe out red wolves?

 

[sol invictus]

I think we need an Albert Einstein of evolution to come along and put some order into what we are seeing. From out current perspective there is great randomness in the events of evolution. From other scientific endevours we see randomness is our lack of understanding, rather than there being a genuine lack of pattern

I don't think so. Not at all, actually.

Every physical process in the world consists of an enormous number of microscopic events. Each event could be considered random (either because it truly is or because we are ignorant of it), and yet the whole process is often extremely close to deterministic, or at least has many aspects which are. There is nothing unusual or surprising about that - it is the most common thing in the world.

I think my example of fire is a good one. The microscopic events which make up a flame are random. The motions of the flame itself are quite random too. And yet the average color of the flame, the fact that it's hot, the fact that it turns wood into ash and produces smoke, the fact that it will start if you apply enough heat to something, and stop if you starve it of oxygen - all of those aspects are predictable with almost absolute confidence.

The statement "fire is random" is essentially meaningless - it's not even wrong.

 

[UnrepentantSinner]

Firstly

Is there a random component to natural selection?

This is where the senmatics card gets played. The environment into which a novel mutation is born is as random as the mutation itself, but the environment is much more static and neutral than the mutations are. An analogy might be that a particular shoe might fit any particular foot, but six inch heels will be selected against in a swampy environment while clogs will be seleced for.

Secondly

Don't the other organisms in the ecosystem also affect the fitness landscape for the remaining organisms?

Yes. But that is the existing, non-random environment into which novel beings evolve. If a scallop evolves a shell impervious to starfish in an environment where there are no starfish, that would be an utterly random evolutionary development, but as I have often cited with blind cave fish, evolution doesn't over engineer - cave fish are selectd for blindness rather than developing an organ which paints their environment in infrared and eyes that see in infrared.

Thirdly

Was there any inevitibity about the emergence of humanity, or a similar organism

1:1 since it happened. Otherwise there are too many factors to consider. I'd place this question of probability in with abiogenesis calculations.

Fourthly

If not, then isn't it reasonable to talk about evolution being random? Especailly if talking to people who do think humanity is somehow special?

Now we're getting back to the semantics issue. As I've said a number of times in this thread, mutations are random and as we've noted a number of times in this thread, evolution - specifically natural selection isn't... except in the "win* the lottery" cases you noted.

* in those cases "win" means lose by virtue of extinction

 

[MG1962]

Um, more assertion without evidence, homo sap sapiens 'wiped' out homo sap neanderthal? Any evidence of that?

Supply me the evidence that Neanderthal is a branch of human evolution rather than a parallel evolution of homo and I will

 

[Dancing David]

Supply me the evidence that Neanderthal is a branch of human evolution rather than a parallel evolution of homo and I will

So in other words you don't have any to pony up, it was just assertion without evidence.


I don't suppose that fossils which show a mixed morphology at the time homo sap sapiens evolved would intrest you? There is a period wher 'gracile' homo sap sap arose from 'archaic' homo sap sap, and there are of the limited specimens we have some that show mixed morphology, like eyebrow ridges and a cranial vault. Then there are others who theorise that homo sap neandethalis was not needing to be a precursor to homo sap sap , just a different out shoot of homo sap sap (archaic), one that was adapted to the glacial enviroment.

What evidence is there that there is some sort of paralell track from homo erectus to homo sap neaderatalis? (Or whichever track you which to suggest).

And what evidence is there of any sort of wiping between homo sap sapiens and homo sap neanderthalis?

Did the coyote wipe out the red wolf or did humans wipe out the red wolf and the coyote moved in?

 

[MG1962]

So in other words you don't have any to pony up, it was just assertion without evidence.

Enjoy

http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.0030175

http://www.jqjacobs.net/anthro/paleo/neanderthal.html

A little low brow, but I am sure you can see the overview

http://www.freerepublic.com/focus/f-news/1066363/posts

http://en.wikipedia.org/wiki/Neandertal_interaction_with_Cro-Magnons

So where is that pony again - I assume your next post will prove the linage of Neandertal

 

[Meadmaker]

I haven't participated in this thread yet, and I confess I haven't read every post, but in skimming through them, they seem a lot like the other threads that went on and on and on.

On the subject of whether or not evolution is random, people have discussed this at length, and a reasonable answer is the one given by Sol in describing fire. Saying "evolution is random" is not even wrong. Likewise, saying "evolution is non-random" is not even wrong.

So, the real question, as I see it, is why people are so insistent that one use is correct and the other is not. It seems to me that both are greatly oversimplified and can only be forgiven if the context is such that it's clear what aspect of the process you are talking about.

With that in mind, I think the real sin in this debate occurs when someone leaps to a conclusion about a speaker based on his bias in the use of a term. For example, I tend to prefer the random description because it emphasizes the nondeterministic outcome, and in particular the fact that we were not planned or designed, but just happened.


The most common justification for getting upset about one use or the other is to note that THEY (the bad guys, the wrong guys, usually, on JREF, the creationists) like one word or another. It would be ok to describe evolution one way, you see, except that THEY describe it that way, and so when you describe it THEIR way, you might help THEIR cause. Indeed, it is sometimes alleged that this is so obvious that the mere use of THEIR term is reason to suspect that you might secretly be one of THEM.

It's quite silly, if you ask me.

There is also an irony present. I've usually heard it said that saying "evolution is random", or any variant thereof, somehow enhances creationist arguments. Despite these claims, in reading creationist arguments, I don't often see the sorts of misuse that are alleged to happen by creationists. I see, much more commonly, a misunderstanding of evolution towards a deterministic outcome. They seem biased to see design, and ask how design could emerge from a random process. Sadly, a common response is to say that it wasn't a random process. In this way, the evolutionist debater has fallen for the trap. He has implicitly accepted, unwittingly, that the end product has a purpose. It doesn't. It just happens to be stable.

To illustrate this, I would like to see example of real, live, arguments posted by real live people in which randomness is misused or misunderstood when discussing evolution. I'm not interested in, "Creationists are always saying that evolution ....." Rather, I would like to see, "Here's a quote from a creationist web site, '......' See how they goofed things up?"

In that way we could see examples of what the OP called valid and invalid usage of the word "random", or of related concepts. e.g. "chance", "coincidence" etc.

 

[EagleEye]

Ya know, I got through just over 1 page of this thread before I had to just stop reading for fear of losing my sanity for at least the next 30 minutes.

All of this "high talk" about randomness, "acausal" stuff, etc, etc... seriously... let's get to the root of the problem here, eh?

The single greatest logical disconnect for the anti-evolution crowd is that they think evolution is purported to be 100% random when it's not. They think that the randomness involves both the CREATION of an organism, as well as it's survivability!

1) They think that for some reason, natural selection is defined as random by the theory, which is of course completely absurd.
2) They think the creation of an object is completely random (ala the "Airplane parts in a tornado" BS).

The best way I can describe the way it actually works is like this...

New organism is created, based on specific plans... throw a tiny wrench in to the works (aka: random mutation somewhere... where just one thing is changed, maybe two...)

There... no random starting point, right? You started with an established SURVIVABLE organism that was able to reproduce, and you end up with... WHAT? We don't know yet... Some small change may cause it to be MORE capable of survival, or it may cause the damn thing to die before lunch today... WHO KNOWS, eh?

So that illustrates how misconception number 2 is wrong... that there is a desired final result (i.e.: we're not trying to see if an airplane is created in that tornado.) other than survivability to reproduce and pass on that one random change.

Now, of course, chaos theory can come in to play... I mean, the random change could allow for survival, but the ONE organism that has it could be struck by lightning or destroyed by a can of Lysol or something... but that in itself is not "random survivability" as much as it's just dumb luck!

So yeah, I only see "radomness" at one point in the whole chain, and that's neither the "starting stuff" nor the "end result"... it's maybe a single molecular alteration caused by a mistake being made down a chain of a MILLION pieces of data... which one is changed is random... and that change can either cause the new organism to survive better, or worse, and that's about it. So... why all this discussion about randomness?

 

[MG1962]

To illustrate this, I would like to see example of real, live, arguments posted by real live people in which randomness is misused or misunderstood when discussing evolution. I'm not interested in, "Creationists are always saying that evolution ....." Rather, I would like to see, "Here's a quote from a creationist web site, '......' See how they goofed things up?"

In that way we could see examples of what the OP called valid and invalid usage of the word "random", or of related concepts. e.g. "chance", "coincidence" etc.

Does this count?

2. Is intelligent design theory incompatible with evolution?

It depends on what one means by the word "evolution." If one simply means "change over time," or even that living things are related by common ancestry, then there is no inherent conflict between evolutionary theory and intelligent design theory. However, the dominant theory of evolution today is neo-Darwinism, which contends that evolution is driven by natural selection acting on random mutations, an unpredictable and purposeless process that "has no discernable direction or goal, including survival of a species." (NABT Statement on Teaching Evolution). It is this specific claim made by neo-Darwinism that intelligent design theory directly challenges. For a more thorough treatment see the article "Meanings of Evolution" by Center Fellows Stephen C. Meyer & Michael Newton Keas.

From
http://www.discovery.org/csc/topQuestions.php#questionsAboutIntelligentDesign

 

[sol invictus]

Here's a quote from http://www.pbs.org/wgbh/evolution/library/faq/cat01.html:

7. Is evolution a random process?

Evolution is not a random process. The genetic variation on which natural selection acts may occur randomly, but natural selection itself is not random at all. The survival and reproductive success of an individual is directly related to the ways its inherited traits function in the context of its local environment. Whether or not an individual survives and reproduces depends on whether it has genes that produce traits that are well adapted to its environment.

From a talk.origins page discussing common creationist misconceptions http://www.talkorigins.org/faqs/faq-misconceptions.html:

"The theory of evolution says that life originated, and evolution proceeds, by random chance."

There is probably no other statement which is a better indication that the arguer doesn't understand evolution. Chance certainly plays a large part in evolution, but this argument completely ignores the fundamental role of natural selection, and selection is the very opposite of chance. Chance, in the form of mutations, provides genetic variation, which is the raw material that natural selection has to work with. From there, natural selection sorts out certain variations. Those variations which give greater reproductive success to their possessors (and chance ensures that such beneficial mutations will be inevitable) are retained, and less successful variations are weeded out. When the environment changes, or when organisms move to a different environment, different variations are selected, leading eventually to different species. Harmful mutations usually die out quickly, so they don't interfere with the process of beneficial mutations accumulating.

A NYT article describing an experiment in which 12 flasks of bacteria all evolved in the same way given the same simulus, thus demonstrating that evolution is deterministic at least sometimes:
http://query.nytimes.com/gst/fullpage.html?res=9905e0d71039f932a25752c1a9659c8b63