Evolution Not Random

[Meadmaker]

Which is more important in understanding or describing evolutionary processes, the color or the purpose of the color? Well does knowing the flower's color will be random help you understand evolutionary processes, or does knowing the purpose of the color will not be random give you a better model to focus on?

Neither. It depends on what aspect of evolutionary processes you are trying to describe.

 

[Meadmaker]

Your last comment here is a good place to present an alternate scenario. Would you consider us the result of accidental random events if life always arose among common circumstances found in the Universe?

Assuming it didn't take the form of intelligent, bipedal, hairless, upright standing mammals, yes.

Is it random that intelligence always increasingly evolves?

It doesn't, but the general question is still good. Is it random that complexity increases? ("Intelligence" involves recognizing and responding to a wider variety of stimuli in an appropriate manner. Such larger numbers of possibilities are one definition of complexity.) No. One strategy (an inappropriate, but commonly used, word) for survival is adaptation to a wider range of conditions. It is predictable that some organisms will evolve in that way. That's one of the predictable, and you could say non-random, elements of evolution.

Is it random that life evolves microorganisms, plants, insects, and animals?

I would think so. I would be extremely surprised to find insects on other planets.

We don't know the answers to those questions and won't until we have more than one example, (Earth), from which to gather data. But as we discover more and more about evolutionary processes, there is evidence accumulating that there is a lot more determinism in the system than there is randomness.

So is it ideological bias or is it evidentiary bias?

As you said, we have only one example, and in that one example we have evidence of both random and deterministic processes, (The paper so poorly summarized from the OP noted that among several variables studied, most evolved in a manner they called deterministic, but some evolved in a manner they called stochastic.) so saying it is "the exact opposite of chance", seems counter to the evidence.

 

[Beth]

No one is denying there is a random component in evolution. Organisms evolve some very clever ways of getting around. Is it useful then to describe evolution as a random process because a swimming organism could evolve its propelling motion from side to side or up and down? Or because an organism can evolve one of two types of eyes? Is it random because eyes can be of different sizes and colors?

Yes, those things make it a random process. We can accurately describe something as random when more than one possible outcome is possible and we can't predict with certainty which outcome will occur -whether that outcome is heads or tails when we flip a coin or the color and size of eyes a species will eventually evolve. Whether or not it's useful to describe it that way is dependent on what your purpose is.

 

[Skeptic Ginger]

Neither. It depends on what aspect of evolutionary processes you are trying to describe.

Of course. The thing is there has been this prolonged discussion over whether the process is random or not. You said it bothered you that Dawkins focused on the nonrandom aspects and claimed the view was ideological. Mijo is obsessively trying to apply a mathematical model to the process which is of very little practical use.

The researchers whose field of expertise this is, are following the evidence and discovering just how determined and nonrandom the processes of evolution actually are. So maybe instead of repeating myself I'll post what some others have had to say about this problem.

Take a look at the 5 major misconceptions about evolution from TalkOrigins:

* Evolution has never been observed.
* Evolution violates the 2nd law of thermodynamics.
* There are no transitional fossils.
* The theory of evolution says that life originated, and evolution proceeds, by random chance.
* Evolution is only a theory; it hasn't been proved.

Further explanation of that 4th falsehood:

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.
...

Evolution 101, Random or Nonrandom?

Now here’s where the random mechanism of mutation hits the nonrandom force of selection. In any given population, individual organisms will have a wide range of mutations. A small percentage of those individuals will have mutations that decrease their fitness, and they will be selected against, with the result being that their genes are taken out of the population’s genome. Another small percentage of those individuals will have mutations that increase their fitness, and they will be selected for, with the result being that their genes are increased in the population’s genome. So over time, we see that a population will become increasingly adapted to its environment, because positive mutations are selected for and negative mutations are selected against. The random mechanism of mutation is utilized by the nonrandom force of selection to drive evolution forward.

We can see examples of this nonrandom selection in the phenomenon known as convergent evolution. Convergent evolution refers to instances where similar physical characteristics have evolved in two different organisms that do not have a close evolutionary relationship. For example, the evolution of wings in both birds and bats. The function of wings is the same in both birds and bats, but the structures of both instances of the appendage show wide differences. For example, the surface area of a bird’s wing is made up of feathers that attach to the entire length of the arm, while in a bat’s wing it is made up of membrane stretched between individual digits. In addition to these obvious structural differences, bats and birds have different ancestries. Bats are mammals, and so belong to the synapsid lineage which parted ways from the reptiles lineage, to which birds belong.

In other words, by two completely different supposedly random pathways, wings developed.

Another good example of convergent evolution can be seen within the mammal lineage itself. The first divergence in the mammal lineage was between monotremes, which are mammals that lay eggs, marsupials, which are mammals that carry their young in pouches, and placentals, which give birth to fully-formed live young. Throughout most of the world, placental mammals have become the dominant groups, but the only place where marsupials have remained was Australia, at least until it was colonized by man. Marsupial mammals evolved to fill the same niches that placental mammals did- including carnivores. The thylacine, or Tasmanian tiger or Tasmanian wolf, looked incredibly similar to the placental wolf, but it was more closely related to the kangaroo or the koala bear. But the same nonrandom selective forces of the environment that shaped the evolution of the placental wolf also shaped the evolution of the Tasmanian wolf, and so they developed very similar physical characteristics.

Again, through completely different pathways, the same predictable features of predator and prey evolved.


Perhaps I can address this another way. What part of the process are you calling 'evolution'? Is giving birth evolution? It is certainly a component of the process but you wouldn't often hear someone saying evolution is determined by choices of birth control and abortion. Perhaps there is an impact by these things but one doesn't discuss 'evolution' itself with a focus on the birthing component. The mechanisms of reproduction are considered in lots of evolution research and discussion. The rate of reproduction has a big impact on evolution. But we don't discuss the theory of evolution with reproduction as the main feature or the starting place. We deal with reproduction only when discussing a certain aspect of evolution, but not 'evolution' itself.

The mutations are randomly occurring. But the mutations themselves are not 'evolution'. We have those 6 billion different human genomes currently walking the planet. Are they all evolving because they have different genomes? Not for that reason alone certainly. It isn't until deterministic nonrandom mechanisms act on those random genetics that evolution occurs. Unless those nonrandom mechanisms affect those random genetics, no evolution occurs.

So, to review, evolution is both random and nonrandom. The instances of individual mutations are random events, and provide a population with a certain amount of variation. This variation is the basis on which the nonrandom selective force of the natural environment directs evolutionary change.

Like I described earlier, there is a random pool to pull genetic variation out of, but the vast majority if not all of the pulling is non-random. Evolution itself is a nonrandom process.

 

[Skeptic Ginger]

Here is the same thing in the words of yet other people whose field of expertise include evolution theory. I tried to find a dissenting scientific view, BTW, but all the dissenting views on the first couple pages of my search were on Creationist web sites.

Evolution by random chance? (The Restless Mind)

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...

...During that process, minor errors in the DNA copying mechanism, rare and completely random, creates imperfect copies of the parent's DNA. These new slightly changed DNAs give rise to "new strains" of the flu virus. This part, "mutation", is the only random part of evolution...

According to mijo, that makes the process random. That's like saying evolution is a reproduction process. It is, but reproduction is a piece that while extremely important, does not represent the whole. And a mathematical model of reproduction is not mathematical model of evolution.

 

[mijopaalmc]

skeptigirl-

You are essentially repeating stock argument that demonstrate you profound ignorance of probability theory and its interface with the evolutionary biology. I realize that evolution may actually be chaotic and therefore only seem random. However, to imply that probabilistic models have "very little practical use" in evolutionary biology is to deny 86 years of research done in the probabilistic modeling of evolutionary processes (reviewed here and here).

 

[Skeptic Ginger]

Funny, as I read through these Creationist arguments they are really just creating straw men to battle. Random mutation cannot account for life as we know it. Well D'uh!

Then they claim, it has to be God's doing. In other words, they pretend we never explained the natural selection part to them.

This Intelligent Design advocate web page actually does a fair job of presenting a case why evolution is not a random process. But then the rest of his argument gets ridiculous.

It's an example of one of the straw man battlers who can't hear the natural selection argument. He has a few lame arguments for why natural selection doesn't work. The web page author takes single objections and purports to answer them. Nothing but straw men arguments on the whole second half of the page.

 

[Skeptic Ginger]

skeptigirl-

You are essentially repeating stock argument that demonstrate you profound ignorance of probability theory and its interface with the evolutionary biology. I realize that evolution may actually be chaotic and therefore only seem random. However, to imply that probabilistic models have "very little practical use" in evolutionary biology is to deny 86 years of research done in the probabilistic modeling of evolutionary processes (reviewed here and here).

It is classic for someone who fails to convince another to believe, it must be because the other does not have the intellect or the knowledge to understand.

No mijo, I understand your mathematical model just fine. The only profound ignorance here is your inability to grasp a point no matter how many ways it has been described, no matter by how many people, no matter with how many different examples and analogies.

If you actually discussed the point being made and articulated your reaction to it, that would at least be some evidence you actually understood why it is that almost everyone in the field of genetics calls evolution non-random while you go on your merry way believing we just don't understand the math concepts.

So let's just look at your examples even though it really annoys me that if you would just read what people are saying to you, none of this would be necessary. Instead of this adversarial discussion, you could have started a very interesting thread on the narrow but relevant application of your obsession.

So people don't have to read through your links, I've pulled out some pieces I think make my point.

Stochastic Models of Evolution in Genetics, Ecology and Linguistics

The most well-established discipline for which this is the case is population genetics, i.e., the study of gene frequencies among a population of reproducing individuals. ...

First, there is reproduction, in which offspring organisms acquire copies of alleles from their parents. Secondly, in the copying process, random mutations can occur which may change one allele to another, or create a completely new allele. Finally, for whatever reason, organisms carrying one allele may end up having more offspring than another: this is selection.

Neutral theories in population genetics (as well as in the ecological and linguistic applications—see below) seem to have a far greater realm of validity that might naively be expected. The idea that many genetic mutations are effectively neutral, that is do not significantly affect the fitness of the carrier, was pioneered by Motoo Kimura [3, 4]. Thus changes in their frequency are due to chance, rather than selection. This is not to deny that natural selection has an important role in the development of morphological and behavioural characteristics, only that random genetic drift has a more significant effect that had hitherto been envisaged. The relationship of the neutral theory to selection was explored further with the introduction of the concept of “near-neutrality”[5, 6], in which the extent to which genes are affected by drift and selection is a function of the effective size of a breeding population.

So they say anyway. But even were it more important than "had hitherto been envisaged", that would still be relative.

Transition between Stochastic Evolution and Deterministic Evolution in the Presence of Selection: General Theory and Application to Virology

The process of evolution is a consequence of the interplay of mutation, selection, and chance on a population of organisms, leading to an observable change in its genetic makeup...

...because of their high replication rates, simple genomes, large population sizes, and high mutation rates, viruses make good models for studying and testing evolutionary theory.

HIV displays a remarkable extent of genetic variation concurrent with a high speed of evolution: in the most variable region of the genome (env), individual genomes within a population from an infected person can vary by as much as 3 to 5% (2, 43, 78); substitutions in env accumulate at a rate of approximately 1% per year (71), 50 million times faster than in the small subunit of rRNA (61). This variation has important consequences. It allows the virus to evolve to infect different cell types (9, 20, 30) and to rapidly become resistant to otherwise highly effective antiviral drugs (10, 47, 50); it may play a role in evading the immune system (4, 56, 73, 79). Furthermore, its high mutation rate (estimated to average about 3 3 1025 per nucleotide site per replication cycle [49]), large population size (variously estimated from about 107 to 108 productively infected cells), and continuous steady state, in which the large majority of virions and productively infected cells turns over every day (25, 77), create a situation which, at least in principle, is amenable to (and requires) mathematical modeling.

Deterministic approaches, including quasispecies theory (15, 26), assume that the population size is very large, such that the frequency of a given mutation at any given time is completely predictable if one knows the initial frequency, the mutation rate, and the selection coefficient (i.e., the differential growth rate conferred by the different alleles). At first glance, such approaches would seem justified by the large number of infected cells at each generation (21); however, a number of factors, such as variation in the replication potential and generation times among infected cells, may lead to an effective population size much smaller than the actual number of infected cells. Stochastic models, as applied to HIV (to this point), proceed from the opposite assumption: that the effective population size is so small (or that selective forces are so weak) that random drift dominates over selection. The hypothesis of selectively neutral mutations has a long, successful history in describing the evolution of organisms where populations are small (and not uniformly distributed) and mutation rates are very low (36). Their applicability to virus populations remains to be established. Many of the assumptions that underlie neutral theory are not appropriate for virus populations, and a number of characteristics of HIV genetic variation in vivo, such as the uneven ratio of synonymous to nonsynonymous changes in different regions of the genome (5, 44, 48), argue against simple application of neutral theory. However, inclusion of selection effects in evolutionary analysis (for example, the coalescent method) presents a mathematical challenge that has not yet been fully solved in a practical fashion, although progress toward this goal has been made recently (42, 55).

(emphasis mine)

First, let me say I understand these papers just fine. Second, I find the one on HIV very interesting and I'm sure to HIV researchers the application of the particular model may be useful. But the discussion in this thread is about evolution. It has not been about the narrow application of a model to a specific circumstance in evolution research.

These papers only illustrates exactly what I have been saying to you had you quit obsessing and actually read the thread. Here the authors are making the case for applying this model to a very specific situation. They are not making the case that evolution is a Stochastic process. They are saying that the particular component of evolution, the random component is useful to consider, in particular situations. The first article merely states the model applies to the non-deterministic component of evolution. And the second paper discusses certain aspects specific to HIV that make looking at the random mutation aspect over the deterministic aspect particularly useful.


If I implied your model was never useful, I retract that. And like I said, I find the HIV paper particularly interesting. I have read a lot on the nature of the HIV and influenza viruses. I was aware of the massive replication that occurs with HIV infection and I have been following the genetic analysis of H5N1 influenza genetic drift as it continues to pose a threat of becoming a human pandemic.

Were I studying the genetic drift of either of those viruses it would be useful to know what one would expect to see with predicted drift without any influence of selection, for their own sake, but also in order to detect influences from selection above the background noise.

So please take a few minutes to read the following paragraph. Read it a couple of times. Let it sink in before you post one more insulting thing about anyone's "profound ignorance of probability theory and its interface with the evolutionary biology".

We get that part. What you don't get is your model describes the random mutation aspect, the random mutation piece of evolution. Your model does not describe evolution. And Wayne's attempt to claim that because random numbers were involved somewhere in the equation, random output had to follow also does not describe evolution.

 

[mijopaalmc]

skeptigirl-

I'm sorry but you are deliberately missing the point of the articles. In both cases, they started with stochastic models, as defined by the fact that the inputs were probability distributions, and noticed that in large populations and over long periods of time the behavior of the system tended toward an equilibrium. This is a well-known phenomenon in probability theory known as convergence of random variables, the simplest and least general examples of which are the central limit theorem, weak law of large numbers, and strong law of large numbers.

 

[Skeptic Ginger]

skeptigirl-

I'm sorry but you are deliberately missing the point of the articles. In both cases, they started with stochastic models, as defined by the fact that the inputs were probability distributions, and noticed that in large populations and over long periods of time the behavior of the system tended toward an equilibrium. This is a well-known phenomenon in probability theory known as convergence of random variables, the simplest and least general examples of which are the central limit theorem, weak law of large numbers, and strong law of large numbers.

So please take a few minutes to read the following paragraph. Read it a couple of times. Let it sink in before you post one more insulting thing about anyone's "profound ignorance of probability theory and its interface with the evolutionary biology".

We get that part. What you don't get is your model describes the random mutation aspect, the random mutation piece of evolution. Your model does not describe evolution. And Wayne's attempt to claim that because random numbers were involved somewhere in the equation, random output had to follow also does not describe evolution.

Until you you reply with an intelligent discussion of the things I said in my post, there is no reason for me to continue focusing on your obsession. I have demonstrated I understand what you've posted. You have demonstrated you don't read what anyone else but yourself posts.

BTW, you may wish to re-read those articles as well. Because they do not present a case for anything other than a narrow application of the stochastic model. I think you missed something there. Perhaps your lack of familiarity with the organisms they were describing.

 

[Skeptic Ginger]

For the sake of anyone else reading the thread, and against my better judgment rewarding you for carrying on a discussion with yourself calling all the rest of us profoundly ignorant "of probability theory and its interface with the evolutionary biology" I will elaborate on why your citation does not say about evolution that "in large populations and over long periods of time the behavior of the system tended toward an equilibrium."

What they said was that in the model NOT IN THE ACTUAL VIRUS POPULATION, and that is a key point,

Naturally, with any research program that requires theory to be integrated with data, there is an inevitable tension between experimental biologists, who deal daily with the complexity of real biological systems, and theoretical biologists, who “simplify, simplify, simplify” in the name of tractability. In this work, our analysis has been limited to the simplest possible case: evolution of a single locus with only two alleles. Many important aspects of evolution, including the effects of multiple loci, recombination, coselection, and migration, were not considered.

 

[Meadmaker]

I have read the talkorigins page before, and I think, if anything, it bolsters my case that ideology is at work here.

The question is whether or not evolution proceeds by random chance. Let us imagine, for the moment, that there were no political controversy surrounding the theory of evolution. (I say "political" because there is no scientific controversy, just a political one.)

This thread has addressed randomness and evolution in various ways, and we've seen that we can view it as a random process or a nonrandom process, depending on what aspect we want to focus on. I liked the pinball machine analogy. Gravity drives the motion of the ball, but various randomizers (bumpers, dust on the board, electrical variations) affect the path. The final state of the ball is known, but the final score is not. So is it random or not? It depends on what you are looking at.

Evolution is even a bit more random than that. If you had a blank pinball table with no bumpers, the ball would still get to its final state. On the other hand, with no random events, evolution would stall. In order for evolution to happen, there must be random chance.

Does that mean it "proceeds by random chance?" I'll let the linguistically inclined argue about the meaning of "proceeds by".

Meanwhile, as long as I'm here, I might address the "non-random" portion of evolution, the selection. What is this selection? Is it real? Can I weigh it? Is there a selector? When we say, "natural selection", what do we mean? Of course it all has to do with "fitness" and an organism that is "fit" is one that is likely to survive and reproduce. (Maybe we should say a gene that is fit, because as Dawkins tells us in "The Selfish Gene", it's actually the gene that is the carrier of evolutionary information. Despite that, I will oversimplify by speaking of organisms surviving as being somehow relevant to evolution.) If an organism survives, we say it has been selected. However, as we know, two organisms can be identical genetically, and one will survive while the other does not. In reality, the "fitness" of an organism is related not to its actual survival, but its probability of survival. If two organisms vary in only one gene, but that gene gives one organism a probability of survival of 0.51, and the other has a probability of survival of 0.49, once the population grows beyond a few individuals, then we know that over time the carriers of the 0.51 gene will overwhelm the carriers of the 0.49 gene.

Once again, we are dealing with probabilities. Even when it comes to selection, what we are dealing with is probability, and here I must side with mijo. If there is probability, there is randomness, by definition.

So, we have randomness in the mutation, without which there would be no evolution, and probability (i.e. randomness) in the selection. Again, does this mean evolution "proceeds by random chance?" If you were to say it did, you would not be wrong, although there would be a possibility of misinterpretation, due to ambiguity of what is meant by "random chance". Those of us who studied mathematics have a particular meaning in mind when we talk about random numbers, and those are numbers described by probability distributions, although the general public may not understand that definition. At any rate, it hardly seems "the exact opposite of chance".

So why do Dawkins and talkorigins use that phrase. It seems quite inaccurate. This is where the ideology comes in, in my opinion. It seems that "the other team", the creationists, use the phrase "random chance". People who are opposed to creationism sometimes feel compelled to say the opposite. If there were no creationists saying that evolution proceeded by random chance, talkorigins wouldn't feel compelled to say it didn't.

There's also an irony here. While creationists on forums and web pages might say "random chance" a lot, the "luminaries" of the ID world never do. I will guarantee you that Michael Behe, poster child for the ID movement, says, without fail, "random mutation and natural selection", every time. So, he's using the same language that everyone here uses. In my opinion, we shouldn't change our vocabulary just to emphasize a difference with the other side, but even if we wanted to, it wouldn't do any good. They say the same things we do.

 

[mijopaalmc]

What makes you think that the model is not generalizable?

I realize that hasty generalization is a problem when discussing models, but it still stands as proof-of-principle that random processes (and yes selection was include as a random process in the model) can lead to orderly results. Moreover, the Blythe review discusses examples of models that include multiple loci, and migration.

 

[articulett]

Don't play along skeptic girl... it's the same people all the time and they must get the last word.

Here's Dawkins review of Behe's book where it's quite clear what scientists are saying versus what those who are like Behe is saying:

http://www.nytimes.com/2007/07/01/books/review/Dawkins-t.html?_r=1&oref=slogin

Behe correctly dissects the Darwinian theory into three parts: descent with modification, natural selection and mutation. Descent with modification gives him no problems, nor does natural selection. They are “trivial” and “modest” notions, respectively. Do his creationist fans know that Behe accepts as “trivial” the fact that we are African apes, cousins of monkeys, descended from fish?
The crucial passage in “The Edge of Evolution” is this: “By far the most critical aspect of Darwin’s multifaceted theory is the role of random mutation. Almost all of what is novel and important in Darwinian thought is concentrated in this third concept.”
What a bizarre thing to say! Leave aside the history: unacquainted with genetics, Darwin set no store by randomness. New variants might arise at random, or they might be acquired characteristics induced by food, for all Darwin knew. Far more important for Darwin was the nonrandom process whereby some survived but others perished. Natural selection is arguably the most momentous idea ever to occur to a human mind, because it — alone as far as we know — explains the elegant illusion of design that pervades the living kingdoms and explains, in passing, us. Whatever else it is, natural selection is not a “modest” idea, nor is descent with modification.


I think it's very clear where those who are considered experts and who actually teach the subject stand and where those who obfuscate the subject stand. Why anyone would want to sound as vague and ignorant as Behe, is beyond me-- but it is not fixable. Beware those who are hell bent on finding it perfectly fine to describe evolution as random despite peer reviewed articles and top scientists who would never do so because it negates the power of natural selection--the essence of Darwin's theory.

They really should read Darwin... not only would they finally understand why natural selection is the "opposite" of random... but they might get a clue from his words: "ignorance more often begets confidence than knowledge". This seems to be the case with Behe.


Check out Behe's blog to see how intractable this is.



http://www.amazon.com/gp/blog/A3DGRQ0IO7KYQ2

Some people need to believe that scientists think all this came about "randomly". (As T'ai popped in to illustrate). These people will never say, "wow, now I see why scientists are going out of their way to show how natural selection is the opposite of random... now I realize that I am being as confusing as Behe with my insistence that it makes sense to call evolution random". They pop in every thread where every person including experts on the subject say that evolution is non random. They must be trying to build up their own imagined expertise. And they insult the actual experts and those communicating clearly and they get upset when people point out that they really aren't saying anything except that the experts aren't as clear as they imagine themselves to be.


I just started this thread, to gather them in one place so people could understand who imagines themselves experts and who really does have expertise and can convey information to others. It's good to know whom you can trust to help you understand topics where you want to learn more and who to avoid.

 

[jimbob]

Skeptgirl, the reason that I dislike dsecrbing evolution as nonrandom is that it implies that there was an inevitability about the evolution of the particular species that we see today.

If we had ten absoultely identical Earths, just before the KT impact and let evoultion run its course; due tothe fact that quantum events do seem to be truely random, and chaotic systems magnify these effects to affect macroscopic events, then you would get different species 65MY later in each "version". There might be humanity, or something akin to it, or there might not. It was not inevitable that our environmental niche was going to be filled.

Would you agree that selection is a probabilistic process, where advantageous traits improve the chances of reproduction, but do not denote certainty?

It is eay to see this with animals that produce a large number of offsping:

Cod stocks are declining, that means that on average, each parent cod produces less than one breeding ofspring.

Each breeding cod produces about 1million eggs. So the chances of an individual egg making it to breed are about 1 in a million. If a small fry had a (dominant) trait that made it 100 times more likely to breed, it would still only have a 1:10000 chance of breeding. At this stage, the trait is 10000 times more likely to dissappear than survive.

If this then did manage to breed, and half its offspring inherited this trait, then you would expect about 5000 breeding offspring from this cod. The trait would get passed on.

Of course in real life, we are usually talking about traits with percentage advantages. But a simialr analysis still holds. With cod, the strongest selection pressure is for as large broods as possible.
​

 

[Kotatsu]

Considering the light sensing cells in plants and starfish, it wouldn't surprise me to see multiple light sensing cells in other primitive organisms.

Uargh, there are no primitive organisms!!!!^^

I have actually forgotten what the original comment that I responded to was. That eyes always occur in some numbers, and not random amounts?

 

[cyborg]

Would you agree that selection is a probabilistic process, where advantageous traits improve the chances of reproduction, but do not denote certainty?

I know it's been pointed out to you a bazillion tmies before but why do you refuse to acknowledge there is a difference between:

"Natural Selection in biology is a process described by probabilities because the entities being selected are done so by a lottery"

And:

"Natural Selection in biology is a process described by probabilities because the entities being selected are done so by a process of game playing between the entities which is generally too complex to fully analyse"

 

[Skeptic Ginger]

What makes you think that the model is not generalizable?

I realize that hasty generalization is a problem when discussing models, but it still stands as proof-of-principle that random processes (and yes selection was include as a random process in the model) can lead to orderly results. Moreover, the Blythe review discusses examples of models that include multiple loci, and migration.

And still you make no effort to address the views which do no agree with you.

 

[Skeptic Ginger]

Uargh, there are no primitive organisms!!!!^^

I have actually forgotten what the original comment that I responded to was. That eyes always occur in some numbers, and not random amounts?

I've heard all the arguments that 'primitive' organisms are more complex. I understand that primitive does not denote time or genetic complexity from the original organisms which evolved. I realize what might be designated as primitive might have more genes than a 'less primitive' organism.

All those concepts are separate issues. A mammal eye is less primitive than a cell which only detects light.

 

[articulett]

I know it's been pointed out to you a bazillion tmies before but why do you refuse to acknowledge there is a difference between:

"Natural Selection in biology is a process described by probabilities because the entities being selected are done so by a lottery"

And:

"Natural Selection in biology is a process described by probabilities because the entities being selected are done so by a process of game playing between the entities which is generally too complex to fully analyse"

They go through so much effort to describe evolution as random (or "probabilistic") and never convey what natural selection is!

To me Jimbob is saying Poker is probabilistic because you don't know how the cards are dealt or how the other people are going to play their hands... and Mijo is saying, Poker is random because the cards are dealt randomly and you can't tell who is going to win before the game is over. And they do it over and over and over again just like in the last thread. They NEVER hear anyone else. They are so very convinced of their expertise though they receive no external cues that people are following them.

The above descriptions are not really "wrong"... but they sure and hell don't say WHAT Poker is! And these imagined experts are critical of articles and experts that actually describe the game! Now what could their motive be? Why don't they hear everyone telling them that they aren't really conveying information exactly like the example above?

Why would the same people come on every thread where someone says evolution is not random to insist that it is? What's the point? Does it clarify anything? Or are they just being T'ai and Behe? To me, they sound like they are trying to convince themselves that Behe is correct in his muddledness and they win points in their head in favor of this viewpoint every time they get the last word without ceding. To me, they seem to be playing a semantics game where they are convincing themselves that they communicate better than actual experts on the subject--or even garden variety lay people--although no one but themselves recognizes their expertise or even understands the point of their posts.

Could a clue penetrate Behe's brain? I suspect the odds are similar to our own self appointed experts on how best to describe evolution. There are lots of ways--but they sure haven't got one.