Or do Darwin’s survivors just not know how to cope with his death? Hey, happens.
Last week, I read with considerable interest Vince Torley’s post, “Will the real neutral theory of evolution please stand up,” and commend it to all.
First, we’ve been hearing about the neutral (or mutationist) theory for years, but explanations vary with the explainer.
That’s okay in principle, given how much is up in the air these days. Torley’s account seems to confirm my guess that neutral evolution is more a movement away from Darwinism in search of a new theory than it is a clearly thought-out theory.
It seems to generally be this:
More recently, neutralists PZ Myers and Larry Moran have spoken out even more boldly, arguing that most of the complexity that we see in the biological world could be largely the result of chance, although they do not wish to rule out a role for natural selection.
Okay, but if natural selection is not a mechanism of change (because it simply cannot create the level of new information needed), what is?
If each and every life form has a vast selection of intricately interlocking possibilities available purely by chance, how did it come to be there in the time available since the Big Bang?
People don’t need to answer these questions in order to research life today of course. But they might want to follow available leads in distancing themselves from current Darwinism.
Okay, let’s be frank. The big news on that front today is a New York Times reporter mounting a defense of good old-fashioned Darwinian racism.
What’s not to not like about that?
This just in: The 1990s phoned and they want the selfish gene back; we say send it express post yesterday.
Note: University of Toronto Prof. Larry Moran has not so far got back to Torley responding to his five questions re neutral evolution, intended to verify the limits and ramifications of the theory. Here they are again:
1. Do you agree or disagree with the view expressed by Motoo Kimura that natural selection is necessary to explain evolution occurring at the morphological level?
2. How do you respond to Dr. Gert Kothof’s claim that the neutral theory “is not a theory of evolution,” because it “is not sufficient to explain complex life and adaptations”? If not, why not?
3. Can you point to any complex structures, functions or behaviors which you believe could not have arisen in the absence of natural selection? (You’ve already nominated the change occurring in the human brain over the past few million years as an event in which natural selection played an indispensable role; what else would you put on your list?)
4. In which of the following events do you see natural selection as having played a decisive role: the origin of eukaryotes, the origin of multicellularity, the 20-million-year Cambrian explosion, the origin of land animals, the origin of the amniote egg, the origin of angiosperms, and the radiation of mammals immediately after the extinction of the dinosaurs?
5. Or is it simply your contention that natural selection, while not playing an important role in the origin of complex structures and novel morphological features, exerts a refining and purifying effect subsequent to their appearance, weeding out non-viable life-forms?
Five questions is enough for one day. In the meantime, I’d strongly recommend that readers of this post familiarize themselves with the articles [here], as they raise a number of interesting issues that will be the topic of future posts of mine.
Reader reflections are encouraged, as always.
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Neutral theory does not claim that natural selection is not a mechanism of change.
Most or perhaps even all intelligent design advocates deny that Darwinian theory is sufficient to explain complex life and adaptations. It’s not therefore a theory of evolution?
VJT is a philosopher and should know better than to make such a specious argument.
Hi News,
Thanks for re-posting my five questions. By the way, I think one of the hyper-links in your post needs to be fixed: the one about the New York Times reporter should be directed here: http://www.uncommondescent.com.....bout-race/
Thanks again.
Hi Mung,
Thank you for your comments. Regarding the first passage you quoted, I think the point that News was making was that on the neutral theory, natural selection is no longer the main mechanism of evolutionary change.
Regarding my second question, which you quoted from: first, I was simply quoting an argument put forward by Gert Korthof, a Dutch biologist; and second, I happen to think Korthof was right. Darwinism purports to be an all-inclusive biological theory. If there is some central aspect of our biological make-up which Darwinism cannot explain (e.g. complexity) then it fails as a theory, and can no longer be considered an adequate theory of evolution, but at best, a mere hypothesis, or outline of a theory.
Hi Mung,
Just to be clear: Korthof himself believes that Darwinism is an adequate theory of evolution, although I would say otherwise, as an Intelligent Design advocate. What Korthof believes is that the neutral theory is not an adequate theory of evolution. As he puts it (see his review at http://wasdarwinwrong.com/kortho37.htm ):
So Korthof thinks (thought) that Darwinism is an adequate theory, but Myers and Moran don’t? They think genetic drift (mutation) is an adequate theory and natural selection isn’t? Is this where we are now?
Could someone please tell me why isn’t genetic drift just a special case of natural selection/ In other words genetic drift is a subset of natural selection.
Remember natural selection is not a process and does not do anything. NS is just an outcome of another process. Genetic drift is just another outcome of the same process. Isn’t this biology 101?
jerry:
I would say that you are right that drift is similar to NS in one aspect, because it is a form of natural fixation, a process whose results are the same as those of natural selection: the expansion and fixation of a gene in a population.
But it is also different, because in drift there is no “selection”, in the sense that NS acts on a subset of new genes that are different from others for a definite property (they confer reproductive advantage), while drift acts randomly, in the same way (IOWs, with uniform probability distribution) on all the genes which are there.
So, NS is a selective natural fixation where the fixation is based on a specific functional advantage, while drift is a random natural fixation, which introduces random variation in the scenario of random variation, and nothing else.
That’s a big difference, even if both are certainly processes which do not “do” anything.
They are not processes. They are outcomes of the same process. At every step of the process that leads to a fixation the allele that survives is subject to elimination but survives. That is called natural selection.
In most cases more than one allele survives the process.. So the case where one survives is a special case.
First, we’ve been hearing about the neutral (or mutationist) theory for years, but explanations vary with the explainer.
Since the neutral theory, and mutationist theories of evolution are entirely separate things, are we left to conclude that you’ve learned nothing in all those years of hearing about them? Your further confusion between drift and mutation in comments here suggest so.
They think genetic drift (mutation) i
. At every step of the process that leads to a fixation the allele that survives is subject to elimination but survives. That is called natural selection.
No. In natural selection the odds are stacked such that some alleles are more likely to survive. Selection is the process when the odds are skewed in some way, drift for the process with uniform odds.
wd400:
You are right. Thank you for helping to clarify that.
Wikipedia had a front page story today about Huntsman (Daddy Long Legs) non-spiders. They have had EXACTLY the same body plan for 400 MILLION years, and the details of the earliest fossils agree remarkably well with Daddy Long Legs living today.
So, does the new Evolution explain Stasis? How can a species have been PERFECTED 400 million years ago and NOT “evolved” since.
There are many, many different Huntsman species alive today. The guess is 10,000 separate SPECIES. But none of them are radically different from each other, and Huntsman are different enough from real spiders to have NOT formed the basis for real spiders.
So a Theory of Evolution must not only provide an Origin of Life from chemicals. It must also explain Stasis from the same mechanisms with which it describes “descent with modification”. And how can Competition explain Stasis? No change after 400 MILLION years would seem to indicate that Competition is NOT a factor.
jerry, perhaps it would help if you could explain what you mean when you say that natural selection and drift are part of the same process.
Drift is a phenomenon of sampling. Even alleles under selection are subject to drift.
wd400, any issues with the bolded text?
I will say it again, natural selection is not a process or mechanism. It is a name given to an outcome of a complicated process of reproduction in different environments. NS does not do anything. It does nothing more than describe a result. The environment affects outcomes, random events affect outcomes, internal genomic processes affect outcomes. NS just describes the outcomes that are due to these processes.
Certain alleles are left after numerous reproductive cycles. The ones that are left are the result of differential fecundity of the offspring as well as differential heredity of alleles. The differential fecundity and heredity may be due to a lot of things and the actual cause is almost impossible to determine. The actual result could be due to random events or to environmental pressures or something else. In all cases the ones that exist after each reproductive round are said to have survived and these alleles will form the new gene pool.
Sometimes this differential fecundity and heredity will end up with one allele and we will probably never know the reason why this happened. In nearly all cases more than one allele will survive, sometimes there will be several alleles at the same loci. Sometimes the differential heredity will be due to strictly random events and we could end up with several or just one allele at a loci. But all must face survival so every allele that persists in a gene pool is said to have survived. Natural selection just describes the alleles that survived. It is the output of fecundity, heredity and the environment and in some cases random processes.
From Allen MacNeill who teaches evolutionary biology at Cornell.
http://www.uncommondescent.com.....ent-306698
So genetic drift which is really just a change in the gene pool due to random heredity events does not change the fact that any allele must face survival. When it survives it is said to have been naturally selected.
I believe drift is a phenomenon of random heredity. it is not a sampling issue since nothing is being sampled. The population is reproducing and certain alleles may appear more frequently than expected due to random events.
All alleles are theoretically under environmental pressures and all alleles are subject to random heredity.
I really couldn’t care less if we called natural selection a ‘process’ in whatever sense jerry want to use to word.
But if you definition ends up saying “when it survives it was selected” then it’s just wrong with the way words are used in biology. Natural selection is the non-random survival of alleles (or phenotypes or whatever).
Likewise, sampling is indeed a useful way to think about drift. Only some sample of the near-infinite set of possible alleles is realised in each generation. That’s why drift is stronger effect in small populations (it’s a small sample drawn from a large population).
jerry:
Again, I agree with wd400. It is certainly true that what survives survives, but still drift and NS are two different models of what survives (different, but not incompatible).
Drift describes how genes can survive by random processes. NS is the classical model of neo darwinism, which describes how genes can preferentially survive because they confer a reproductive advantage. In the NS model, it is important that the gene survives for reasons related to the gene itself, because that is an integral part of how neo darwinism tries to explain the generation of complex functions (without succeeding, but that’s another story).
Drift is by definition unrelated to the functional activity of the gene, and to any possible reproductive advantage it may confer. It is possible in theory that a gene which confers reproductive advantage be fixed by drift, but as the genes which confer reproductive advantages are a minimal part of the total, that effect is not relevant. The few genes which confer reproductive advantage will be fixed by a NS process, if they are fixed. The probability that they may be fixed by drift is really negligible.
It isn’t negligible if the selection coefficient s and the effective population size N_e are both sufficiently small (to wit, if 4×N_e×s is smaller than 1). A “preferred” allele may be lost by drift or fixed more thanks to drift than to positive selection, and a deleterious allele may be fixed by drift despite selection against it, or lost — again more thanks to drift than to purifying selection. The importance of drift is inversely proportional to the effective population size, which is why fixation by natural selection is more likely in big populations than in small ones (where unpredictable random fluctuations may override the effects of selection).
Piotr- Natural selection is eliminative and “selection coefficients” only exist in computer programs.
And no one knows what it takes to get a new allele fixed.
jerry- I understand what you are saying wrt natural selection. However natural selection can be defined as: differential reproduction due to heritable chance mutations. So that would also be or could be considered to be the process.
Genetic drift wouldn’t be special case of natural selection because it is not eliminative.
As for natural selection being non-random, well all that just means is not every organism in a population has the same probability of surviving/ being eliminated. It isn’t magical non-randomness.
Everything that wd400 wrote was nonsense and you agreed with him. For example, I suggest you look at how he used the term “sample” and justify your comment. I didn’t respond to his comment because it was fatuous. There is too much response on this site to nonsense comments.
———————–
Every offspring that arises is subject to the pressures of the environment no matter how the alleles it possesses came about. There will never be a perfect replication of the gene pool due to how reproduction works. So the frequency distribution of alleles is constantly changing in small amounts by natural processes . But if an allele frequency change remains then it was not eliminated by environmental pressures no matter how the frequency distribution of the allele arose and one then says that natural selection allowed this allele frequency to remain. So called selection pressures or environmental pressures are constantly operating. They usually operate to keep the gene pool pretty much the same but nonetheless they are still operating. And the gene pool as I said always changes a little from generation to generation.
So when these slight allele frequency changes due to differential heredity (a population frequency distribution different due to random reproductive events), it does not mean that environmental pressures stopped operating. People are confusing the processes of reproduction that led to a slight change in the gene pool with the environmental pressures that affect the survival of particular organisms. Or rather with the survival of a subset of the population of the organism that possess a certain allele or combination of alleles. If an allele becomes fixed it went through a long process of environmental pressures and survived. It was naturally selected at each step of the way.
Genetic drift is a red herring that never adds anything to a gene pool. To say that it is a major factor in evolution is ludicrous. It only subtracts as does natural selection. Look at the comment by Allen MacNeill and the only thing that matters is the origin of variation and the survival of this variation.
jerry- there is more to evolution than producing adaptations. That genetic drift is more of a factor than natural selection should tell us how impotent evolution really is.
Let’s suppose we have two alleles, A and a. Natural selection tends to reduce the reproductive success of the carriers of a in comparison with A, so while carriers of a produce 100 fertile offspring, carriers of A produce 101, on the average. The ratio 101:100 can be expressed as (1+s):1 (here, s=0.01). This s, ranging from -1 to + infinity, but usually rather close to zero, is the selection coefficient favouring A relative to a (the competing allele). It’s positive for A despite the “eliminative” character of selection in this case.
An alternative way of defining the selection coefficient is 101:100 = 1:(1-s’), where s’ is the selection coefficient against a (relative to A). It doesn’t matter much which definition you prefer, as long as you use one of those coefficients consistently (they are not quite equivalent but can easily be transformed into each other: s’ = s/(1+s)).
If you have a large population in which neither A nor a make a statistically significant difference in terms of advantage (or disadvantage) to their carriers, selection can’t fix or eliminate either of them. But in a finite population drift alone will eventually fix one of them at the expense of the other, even if complicating factors such as mutation and/or migration can be neglected.
Piotr, nature isn’t as simple as your model
From “What Evolution Is” (Mayr) page 117:
Page 118:
jerry:
a) My agreement with wd400 was limited to what he says in post #16, and in particular to the following statement:
“Natural selection is the non-random survival of alleles (or phenotypes or whatever).”
I think that your use of the concept of NS is not correct, or at least does not correspond to what everybody (except maybe MacNeill) means with that name.
However, I have a perfect agreement with you, limited to the following statement:
“Genetic drift is a red herring that never adds anything to a gene pool. To say that it is a major factor in evolution is ludicrous. It only subtracts as does natural selection. Look at the comment by Allen MacNeill and the only thing that matters is the origin of variation and the survival of this variation.”
Whatever MacNeill may think, the origin of complex functional variation is one and only one:design.
But the product of good design can certainly be expanded and fixed by NS (not drift), because of its high functionality.
Of course it isn’t. But I’m only trying to tell you what some fundamental notions of population genetics mean. There are more sophisticated models which take into account mutations, lateral gene flow, degree of inbreeding, structure of the population, etc., etc., etc. (whatever is relevant in a given situation) Of course you can always say, “It’s a model, not reality”. But the same can be said of physics, or any science. Models aren’t supposed to represent the real world with 100% fidelity; but they help you to understand what happens in the world by focussing on the most important aspects of real-world phenomena.
Piotr:
I understand pop gen. I also understand that it is useless wrt reality and it doesn’t help us understand reality.
That said, no one can model unguided evolution doing what it is claimed it has done.
+
is like saying, “I understand gravity… and no-one knows what makes the Earth orbit the Sun.”
Piotr, pop gen is not based on reality and no one has ever verified its equations. And no one has ever observed a new allele reach fixation in the wild.
OTOH we have a very good understanding of gravity and why the earth orbits the sun.
I doubt any physicist would ever say that gravity is as well established as pop gen.
Population genetics has nothing to do with the evolution debate. It only deals with what is already there. What the debate is about is the origin of novel variation. After the variation appears, natural processes will affect how widespread the variation becomes.
So natural selection and genetic drift are real but meaningless concepts in terms of the debate. People tend to want to use the term “natural selection” as a special case of the natural environmental pressures that are always working on populations. Eventually there will be a different skew of allele frequencies. When does one say in this process that NS has taken place? The answer is that NS takes place at every step. It is just that no one sees anything of interest in nearly all the steps in this process. Most of the times there is no essential difference in the gene pool.
So tell me when you say there is NS? Also the changes in the gene pool could be random or due to environmental pressures or a combination of both.
So tell me when you say there is NS?
When can measure its effect, and see a pattern (in survival or reproductives, heterozygosity, types of substitutions occuring) that is best explained by selection and not drift.
You are really all at see on this, I’m afraid.
Also the changes in the gene pool could be random or due to environmental pressures or a combination of both.
Yes, of course. And we have names for the process when it’s largely due to the random processes (drift) and when it’s largely due to differential success of variants (selection).
(I should say, following Mung’s comment: indeed drift is still in operation on very large populations and with large selection coefficients. It’s just the relative strengths of the random effects is dwarfed by the directional ones in such cases)
wd400:
What kind of non-random force does natural selection apply to a phenotype? How is it measured? What is the unit of measurement? In what direction will the force be applied in a given situation?
Hi News,
Thanks for your question. Gert Korthof recognizes that Darwin was wrong about a number of things, but still regards neo-Darwinism as an adequate theory of evolution. You can find out more about his current views here: http://wasdarwinwrong.com/kortho13.htm .
PZ Myers and Larry Moran, on the other hand, regard the neutral theory of evolution as adequate at the genetic level, although they acknowledge a limited role for natural selection as well. I’m still trying to ascertain which aspects of evolution they think require an explanation in terms of natural selection.
Selection doesn’t apply a force to a phenotpye. It changes allele frequencies, or the distribution and mean of phenotypic traits in a population. The ‘units’ are the units of the phenotype under selection, and selection will be directional, stabilizing or diversifying depending on the fitness of the variants under consideration.
wd400:
Now, come on. Let’s consider whether natural selection can “change allele frequencies” (or do anything for that matter) if it doesn’t apply some kind of force.
Or perhaps what you really meant to say was:
That’s more like it.
You sound suspiciously like someone that wants to play a round of amateur philosophy. Natural selection is a pretty well understood phenomenon, it arised from non-random survival of heritable characters. As i said to start, if you want to spend energy arguing about “processes outcomes and forces” your welcome to, but it will do nothing to help us understand biology, so i’ll skip that one.
jerry:
*sigh*
Let me try to help. Alleles are being sampled. How many alleles make it into the next generation (or not).
How many alleles make it into the next generation is not solely determined by their “selective” value.
A particular allele may be very beneficial to the carriers of that allele, but if only one individual in a large population carries that allele, tough cookies.
Random heredity. Taking samples.
jerry:
Random events would include what? Genetic drift? If not, why not?
So your position is that natural selection is an amalgamation of of all processes, both random and non-random?
jerry:
The claim that genetic drift is a red herring that never adds anything to a gene pool is a red herring.
To say that random events are not a major factor in evolution is ludicrous.
vjtorley:
Given that neo-darwinism cannot explain the things that Gert Korthof thinks ought to be explained by a theory of evolution (complex life and adaptations), why doesn’t he likewise hold that neo-darwinism is not a theory of evolution? At least that would be consistent.
Alleles under selection will tend to be represented in greater numbers in each succeeding generation.
If you take a random sample from that population, alleles which exist with greater frequency are more likely to appear in the random sample.
Non-random survival just means that some organisms have a higher probability of surviving than others. Big deal. That could be anything- better sight, better hearing, better taste, faster, slower, bigger, smaller, taller, shorter, eyes or no eyes, legs or no legs- contingency rules.
Joe:
So what does random survival mean, Joe? Does it also mean that contingency rules?
wd400:
Nope. Not philosophy. Just interested in scientific clarity.
Well, that is the assertion, isn’t it. People keep wanting to claim that natural selection imparts some “non-random” direction to the process of evolution. (Makes the whole story seem more believable that way, of course.) But in fact when we pin down what actually happened with the population, it is very much random.
Unless, of course, one wants to point back to mere ‘survivability’ as the “non-random direction” natural selection imparts to the process. In which case we are dealing with a useless tautology.
Yes, better to stick to vague assertions about natural selection’s power than to actually delve into the details. That’s fine.
Look, I have no problem with someone using the term “natural selection” — as long as they realize it is an after-the-fact label and as long as the acknowledge that natural selection doesn’t actually produce anything, doesn’t cause anything.
Well, that is the assertion, isn’t it. People keep wanting to claim that natural selection imparts some “non-random” direction to the process of evolution. (Makes the whole story seem more believable that way, of course.) But in fact when we pin down what actually happened with the population, it is very much random.
No. By definition selection means reproductive sucsess that is not random with respect to some heritable trait. Whatever point you are trying to make with this quibbling, selection is not random.
Mung:
By what Mayr said it would mean that all organisms have the same probability of surving/ being eliminated.
You guessed it. Give Mung a bisquit.
wd400:
Contigent upon the environment, of course.
Yes some organisms may have a higher probability of surviving than others depending upon the enivironment. Big whoop.
Whatever is good enough to survive gets the chance to try to reproduce. It’s as non-random as the spread pattern of a sawed-off shotgun shooting bird shot.
wd400:
If by “quibbling” you mean that I am interested in the details and am not satisfied with descriptions of natural selection that are vague, overly-broad, and (often) self-contradictory, then I plead guilty as charged.
If people anthropomorphize natural selection and keep talking about it as though it “selects” (it doesn’t) or it “produces” (it can’t), then I will continue to quibble.
As to the claim that natural selection imparts some non-random directionality to evolution:
That sounds great. Until we consider the details.
How do you suppose that heritable trait came about? Some random mutation or some random biochemical error occurring in some random organism, which happens to confer a reproductive advantage in a particular environment, based on the predators in the environment, the food supply, other competitive organisms and a hundred other random factors, any of which could change at any time.
So sure, we could say that natural selection temporarily “preserves” that trait. That is until some other random factor changes — new predators, different food supply, different competition, changes in the weather, whatever — in which case some other trait will come to the forefront.
So the trait that we claim was “selected” by natural selection is, at the end of the day, nothing more than a result of all the random factors that existed prior and that happen to exist today. That is all the substance there is to the idea of natural selection: whatever happens to work today, works today. Yesterday was different; tomorrow might be something else as well.
We could fix your statement as follows:
At least that is closer.
—–
Suppose I have a random number generator that generates a string of 100 random digits. Then I have a “selector” that always selects the 6th digit in the string. Then I go out and claim to people that because my selector always selects for the same thing (perhaps I can even prove to their satisfaction that it always perfectly, without fail selects the 6th digit) that the result of my process is not random. I claim that my selector is a “non-random” factor I have introduced into the process. People would rightly raise an eyebrow and point out that the selection of the digit does not change the underlying substantive randomness of the process.
Claiming that natural selection somehow imparts directionality or somehow makes evolution non-random commits the same error.
I’m afraid this is just a longer version of one of Joe’s catechisms, and hardly worth more time.
Suppose I have a random number generator that generates a string of 100 random digits. Then I have a “selector” that always selects the 6th digit in the string.
Then you selected number would be random with respect to its value, which makes a pretty poor analog to natural selection.
There is nothing that selects. And selection what ever it is, certainly does not change allele frequencies. There are only environmental pressures affecting the fecundity of individuals of a population in various ways and random reproductive processes that affect the proportion of alleles in the next generation. There are also random forces which affect the environment. The result is frequently a different distribution of alleles in the next generation.
Over time this distribution of alleles could be pretty much the same as the current gene pool, slightly different in some alleles or dramatically different. Call this process what you may but nothing selects anything. The outcome of parts of this process has frequently been called natural selection but natural selection is not the process and never selects anything. It is just a result.
Some call parts of the process genetic drift but genetic drift when it actually occurs in any population, is happening along with changes of the gene population due to environmental pressures. It will almost be impossible to determine when or if ever genetic drift happens. There will always be changes in the gene population due to random events each generation.
All of the outcomes from these processes of environmental pressures or random process affecting allele frequency does not add anything new to the gene pool. They actually subtract alleles especially in the case of genetic drift and make it less likely the gene pool could survive in the future. Thus these processes are meaningless in the evolution debate. They certainly have usefulness in other areas but not in evolution.
The only thing that is of interest in the evolution debate is the origin of new variation and its integration into the gene pool. So the discussions on natural selection and genetic drift are pointless for the evolution debate.
The only thing that is of interest in the evolution debate is the origin of new variation and its integration into the gene pool.
And selection is key to understanding that “integration” part: what happens to new variants, from what starting place is variation created in subsequent generations.
I really think that if you can concoct a story that makes natural seleciton “meaningless in the evolution debate” then you need to check your premises.
wd400:
Well, I realize it is unlikely I will be able to cut through years of indoctrination that natural selection is actually doing something or imparting a non-random direction to the process. So you are right, maybe not worth much more time. But hopefully some lurker will be reading and say, “Wait a minute, hmmmmm . . .” 🙂
Nope. No analogy is perfect, of course, but it is a pretty good analogy and well worth considering.
The mistake comes in thinking that natural selection is selecting some definitive special “value.” It isn’t; at least not over time. The “value” that natural selection selects (anthropomorphizing again for a moment) is just as random as my random number — a temporary blip on the scene of life until the myriad random organismal and environmental factors change, and then something entirely different may be “selected.”
All anyone has ever been able to articulate to try to explain natural selection’s “non-random” selection process is a vague general claim that natural selection selects for more reproductive success. Yet a moment’s observation of the natural world will tell us that this doesn’t have much substance.
What has been “selected” in the real world? Larger organisms, smaller organisms. Faster organisms, slower organisms. More complex organisms, simpler organisms. Organisms with fur, organisms without fur. Eyes, lack of eyes. Legs, lack of legs. Longer gestation periods, shorter gestation periods. More offspring, fewer offspring. And on and on. There isn’t anyone who can give us any prediction or assessment about what will happen over time — precisely because it is essentially a random series of events, there is no directionality. Why does any particular organism exist? Who knows? Stuff Happens.
The whole series of events and environmental factors that lead to one organism happening to survive is a crapshoot. And we deceive ourselves if we think we can apply a label of natural selection to the stochastic results of the process and make what was a crapshoot into not a crapshoot.
wd400:
Joe’s catechisms come from the high priests of evolutionary biology, for example Mayr in “What Evolution Is”:
Certain properties means it all depends and it obviously can be more than one.
Yes chance plays a much smaller role but much smaller in relation to 100% is what, 70%? 50%?
Fitness can be from any number of characteristics, again, it all depends.
All wd400 has is wd400 and is failing to make a point.
Frankly, Im amazed you would spend so much effort saying so little. Evolution is a contingent process, sure. So what?
If selection always made things {larger, smaller, faster…} then it wouldn’t help us understand biology since the world is fill of large and small and fast and slow organisms. Theories of adaptation have to explain why organisms fit their environment so well. Selection is a process by which organisms become better-adapted to their environment. If environments change selecton may help populations track that change, I don’t know why you would think that is a weakness of natural selection.
wd400:
How does it do that? Whatever is good enough survives to get the chance to reproduce.
Populations wobble but don’t change very much. That is the “strength” of natural selection.
From Chapter IV (Wobbling Stability) of “Why is a Fly Not a Horse?”:
(snip a few paragraphs on peppered moths)
I do not deny what happens to a novel variation after it arises is of interest and especially how it affects the viability of the organism is very important. But for the evolution debate it is much more important to understand how the variant arose and how it became functional. For without this there would never had been anything but very simple microbes around after OOL. So far no one has been able to provide a coherent rationale as to how life changed since the first cell. It is all stories.
I have been following this debate for 15 years and I have read a lot by people on both sides of the debate and have yet to see anyone make a good case for natural selection resulting in anything meaningful. Perhaps those who support this concept should provide the rationale for why it is important.
Sarcastic remarks don’t seem to do it. When one resorts to them, it is a sign of a lack of a rationale as opposed to it being obvious or even that there is one. It is the sign of a non-serious comment.
Caveat: Probably in the next few years the whole debate will turn away from how elements in the coding region arose and turn to how the regulatory regions arose and just what these sequences do.
wd400 @55:
Great, that’s all I want. An acknowledgement that we are dealing with a contingent process. An acknowledgment that natural selection doesn’t somehow make the contingent process non-contingent.
We’re on the same page. Thanks.