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ORIGINAL: Aristocrat
Biblical creation is six days....and about the earth being only a few thousand years old.

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I assume you mean selective pressures. It isn't necessary that because one sea creature changed as a result of, say, a snowball Earth that another creature changed. There's plenty of reason to suspect that a major global or regional event would have a profound effect on relevant species (in the case of a global event, the relevant species would be all of them), but there's little reason to say that these relevant species would all necessarily be impacted. If you wish to contend that there have been selective pressures that would radically (or even minorly) alter the horseshoe crab, you're going to need to present evidence.

What are the major events you contend are relevant to the horseshoe crab?

How is the horseshoe crab affected?

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There quite specifically is a reason to think this. I already cited it. An organism which is highly adapted to its environment has a smaller range of all possible beneficial mutations when compared to less well adapted organism. Let's set a max number of 100 possible beneficial mutations that could occur to an organism. The actual number of possible mutations is so near infinite we may as well call it that, but that isn't important. Our hypothetical states 100 possibilities. A poorly adapted organism can have 90 of these. The other ten would be deleterious because of what it happens to be. In other words, five mutations could be five different kinds of claws, but because of the cumulative effect of natural selection selecting another 5 mutations, our organism is some sort of finned sea creature. Claws are no good.

Now we take a well adapted organism. It only has a possible range of 10 mutations because it has already gone through 90 others (or maybe a combination of, say, 60 which canceled out the benefit of another 30). The total set of possibilities is smaller. This means the probability of a beneficial mutation is less for the well adapted organism than the poorly adapted organism. The point is assisted if we consider 100 possible neutral mutations, 100 possible deleterious mutations, and, of course, the 100 beneficial mutations.

All these numbers are arbitrary, but the point should be clear. A more well adapted organism has less room with which to improve. If it has fully exploited its niche, why would it need to evolve? The horseshoe crab has done this, at least insofar as its body is concerned.

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Most mutations are neutral. Many are deleterious. Neutral mutations do no lead to large scale changes unless a separate beneficial mutation occurs which exploits the formally neutral genes (natural selection can also act upon this). Biologists don't claim this to be the way in which the vast majority of large scale changes occur. Deleterious mutations obviously are weeded out.

That "mutational change is rather ordinary and constant" doesn't prove any point because mutations do not always (nor usually) lead to change in species. You can say mutations are as constant and common as you wish. This does not mean we should expect change. Furthermore, a critical flaw in your point is that it assumes beneficial mutations are constant and ordinary. Mutation is random. Why would anyone assume anything is constant concerning something which is random?

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I saw your claim that planets and beetles have remained constant. Do you have an way of substantiating this claim?

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ORIGINAL: Jhud

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I assume you mean selective pressures. It isn't necessary that because one sea creature changed as a result of, say, a snowball Earth that another creature changed. There's plenty of reason to suspect that a major global or regional event would have a profound effect on relevant species (in the case of a global event, the relevant species would be all of them), but there's little reason to say that these relevant species would all necessarily be impacted. If you wish to contend that there have been selective pressures that would radically (or even minorly) alter the horseshoe crab, you're going to need to present evidence.

What are the major events you contend are relevant to the horseshoe crab?

How is the horseshoe crab affected?

Well there have been a number of extinction events that presumably killed off trilobites, marine reptiles, and drove wholly marine animals onto land. Are you suggesting that these events would have had a dramatic effect on animals that existed in the oceans throughout the world, and none whatsoever on horseshoe crabs? That’s an extraordinary claim.

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Or that the events that killed off the dinosaurs and drove the proliferation of mammals had no effect on the platypus, or army ants? Or crayfish?

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There quite specifically is a reason to think this. I already cited it. An organism which is highly adapted to its environment has a smaller range of all possible beneficial mutations when compared to less well adapted organism. Let's set a max number of 100 possible beneficial mutations that could occur to an organism. The actual number of possible mutations is so near infinite we may as well call it that, but that isn't important. Our hypothetical states 100 possibilities. A poorly adapted organism can have 90 of these. The other ten would be deleterious because of what it happens to be. In other words, five mutations could be five different kinds of claws, but because of the cumulative effect of natural selection selecting another 5 mutations, our organism is some sort of finned sea creature. Claws are no good.

Now we take a well adapted organism. It only has a possible range of 10 mutations because it has already gone through 90 others (or maybe a combination of, say, 60 which canceled out the benefit of another 30). The total set of possibilities is smaller. This means the probability of a beneficial mutation is less for the well adapted organism than the poorly adapted organism. The point is assisted if we consider 100 possible neutral mutations, 100 possible deleterious mutations, and, of course, the 100 beneficial mutations.

All these numbers are arbitrary, but the point should be clear. A more well adapted organism has less room with which to improve. If it has fully exploited its niche, why would it need to evolve? The horseshoe crab has done this, at least insofar as its body is concerned.

Your reasoning is rather circular. It’s well adapted because, well, its still here. It’s still here because, well, it’s well adapted.

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This of course doesn’t explain why animals which seemed equally well adapted in the same environments are no longer here, or how it is that changes to the same environment presumably caused other animals to drastically change.

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Most mutations are neutral. Many are deleterious. Neutral mutations do no lead to large scale changes unless a separate beneficial mutation occurs which exploits the formally neutral genes (natural selection can also act upon this). Biologists don't claim this to be the way in which the vast majority of large scale changes occur. Deleterious mutations obviously are weeded out.

That "mutational change is rather ordinary and constant" doesn't prove any point because mutations do not always (nor usually) lead to change in species. You can say mutations are as constant and common as you wish. This does not mean we should expect change. Furthermore, a critical flaw in your point is that it assumes beneficial mutations are constant and ordinary. Mutation is random. Why would anyone assume anything is constant concerning something which is random?

The problem is of course is that we aren’t dealing with 5 years or 5000 years, but you are claiming that in 500 million years, an organism that is threatened with survival today endured among the most massive environmental changes and remained, by all evidence, the same. This can only mean a few things – it simply didn’t change in any way that could be affected by the environment – that is, it wasn’t evolving – or environmental changes don’t actually act on mutations to effect a significant change in structures or systems of organism. So while evolution can claim some organisms evolved, we know from observation that evolution played no part whatsoever in the history of certain life forms, contra Darwin.

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I saw your claim that planets and beetles have remained constant. Do you have an way of substantiating this claim?

I listed the articles at the beginning of the thread.

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The best scientific theory we have predicts this. Since it is all we have, this is what we work with.

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What makes you think that it had no effect on these creatures?

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The theory of evolution predicts that when a creature remains static for a very long time, it would be because it is well adapted to it's niche, and there is no need for it to change. Since the ToE is the best scientific theory we have, it makes sense to use it in this case.

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It is not a circular argument. It is the output we get from the theory of evolution, when we feed the theory with the evidence at hand.

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Could you be more specific, and cite your sources please?

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How do you come to this conclusion? Could you include your actual argument?

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It is simple to defeat it. All I have to do is say the following : "Species that remain static poses no problem for evolution."

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All we have to work with are the fossils. The fossils show us that the parts of the horseshoe crabs that can actually fossilize did not change a lot. That is all we can deduce from this. We cannot see the genes, so we cannot make any arguments about the mutations that may or may not have occurred.

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Your only argument seems to be that you find it unlikely that the niche the crabs occupy could have remained static. Why do you think this? Why do you think that a niche MUST change

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Also, just because YOU can't imagine a niche remaining static, does not mean that it cannot remain static.

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ORIGINAL: BVZ

Juhd, your argument is a weak one.

It is simple to defeat it. All I have to do is say the following : "Species that remain static poses no problem for evolution."

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If Jhud has answers for the apparent stasis of a few species, then I would like to hear them. Whatever his answers are, they should be compatible with the species which have taken such complicated paths. If he doesn't have an answer for 99.9% of species, I wonder why just a few would be significant to him?

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ORIGINAL: Jhud

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If Jhud has answers for the apparent stasis of a few species, then I would like to hear them. Whatever his answers are, they should be compatible with the species which have taken such complicated paths. If he doesn't have an answer for 99.9% of species, I wonder why just a few would be significant to him?

Well, I have simply listed a few well documented ones. Obviously documentation of the presumed 99.9% of species would fill tomes. New cases of stasis are being discovered regularly, indeed, stasis appears to be the rule – sudden appearance, explosive diversity, and stasis. I would be interested in exceptions, because I would guess these are much rarer than what I have documented.

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So you are talking about "intermittant stasis" of all species? Is that what you are suggesting?

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ORIGINAL: Jhud

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So you are talking about "intermittant stasis" of all species? Is that what you are suggesting?

I don't think 500 million years of not changing could rightly be called 'intermittent'.

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You mentioned the rule of sudden appearance, explosive diversity, and stasis.

Actually extinction is the rule.

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ORIGINAL: Jhud

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You mentioned the rule of sudden appearance, explosive diversity, and stasis.

Actually extinction is the rule.

I disagree. I think most of the major forms of animals and plants that ever existed continue to exist.

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What do you mean by "major forms" of animals and plants.

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ORIGINAL: Jhud

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What do you mean by "major forms" of animals and plants.

Body plans, structures, systems, organs.

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All species have body plans, structures systems and/or organs. What did the extinct ones have that is different?

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ORIGINAL: Jhud

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All species have body plans, structures systems and/or organs. What did the extinct ones have that is different?

Exactly.

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Jhud, is there any form of life that does not have either body plans, structures systems and /or organs?

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Well there have been a number of extinction events that presumably killed off trilobites, marine reptiles, and drove wholly marine animals onto land. Are you suggesting that these events would have had a dramatic effect on animals that existed in the oceans throughout the world, and none whatsoever on horseshoe crabs? That’s an extraordinary claim.

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Or that the events that killed off the dinosaurs and drove the proliferation of mammals had no effect on the platypus, or army ants? Or crayfish?

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Your reasoning is rather circular. It’s well adapted because, well, its still here. It’s still here because, well, it’s well adapted.

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This of course doesn’t explain why animals which seemed equally well adapted in the same environments are no longer here, or how it is that changes to the same environment presumably caused other animals to drastically change.

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The problem is of course is that we aren’t dealing with 5 years or 5000 years, but you are claiming that in 500 million years, an organism that is threatened with survival today endured among the most massive environmental changes and remained, by all evidence, the same. This can only mean a few things – it simply didn’t change in any way that could be affected by the environment – that is, it wasn’t evolving – or environmental changes don’t actually act on mutations to effect a significant change in structures or systems of organism. So while evolution can claim some organisms evolved, we know from observation that evolution played no part whatsoever in the history of certain life forms, contra Darwin.

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I listed the articles at the beginning of the thread.

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Again, the horseshoe crab is the exception, not the rule. If we were to find something anywhere near 1% of animals that changed so incredibly little, evolution may have a problem (or rather, more questions), but the few cases which you can cite aren't convincing evidence that stasis is a problem for evolution.

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Certain animals, especially aquatic ones, would tend to be far less affected by the asteroid that hit Earth than dinosaurs.

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Not at all. You've simply ignored the entire argument.

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The environments are not necessarily the same from organism to organism. Also, simply because something "seems" to be adapted equally well to you does not mean that it actually is.

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Again, you'll have to cite a specific global event and then you'll need to show why you think this should change the specific environment of the horseshoe crab.

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Plants and beetles have not remained constant in the same way in which horseshoe crabs have, nor do the articles say that. In no way have plants and beetles remained in a 500 (or however long each respective article cites) million year long stasis.

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This is rather fruitless. You're basically arguing (and poorly) that punctuated equilibrium is an issue for evolution. It is not.

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It's an interesting discussion, but it tends to be more of a discussion point for creationists than biologists.

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ORIGINAL: Mountaineer

This is rather fruitless. You're basically arguing (and poorly) that punctuated equilibrium is an issue for evolution. It is not. It's an interesting discussion, but it tends to be more of a discussion point for creationists than biologists.

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ORIGINAL: Mountaineer
Again, the horseshoe crab is the exception, not the rule. If we were to find something anywhere near 1% of animals that changed so incredibly little, evolution may have a problem (or rather, more questions), but the few cases which you can cite aren't convincing evidence that stasis is a problem for evolution.

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ORIGINAL: Jhud
I would say that most organisms alive today have forms that are quite old, and those we only find in the fossil record remain in stasis for at least tens of millions of years. I would entertain examples to the contrary – but I imagine they are infrequent at best.
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None of which denies the fact that there are a number of organisms that remained in stasis throughout the events that were said to drive the evolution of other organisms.

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ORIGINAL: Mountaineer
This is rather fruitless. You're basically arguing (and poorly) that punctuated equilibrium is an issue for evolution. It is not. It's an interesting discussion, but it tends to be more of a discussion point for creationists than biologists.

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ORIGINAL: Jhud
Punctuated equilibrium, a rather dated concept, sought to explain sudden changes; the cases I have detailed are devoid of change.

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They are devoid of body changes. This doesn't make your case that these animals failed to evolve. Indeed, you cannot make that case because you do not have the genetic evidence to say one way or the other. Again, this is rather fruitless. Your assertion is great creationist fodder, I suppose, but it doesn't go much beyond that.

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ORIGINAL: Jhud

Well, again, if it is the case that phenotypic changes represent evolutionary changes in the fossil record, then no phenotypic changes certainly indicate a lack of evolutionary change in the fossil record. You could of course dismiss the entire fossil record as irrelevant to evolution I suppose, but what would you have left?