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Topic: Proposed algorithm for evolution by ID
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yersinia
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posted 16. March 2003 04:25
quote:
The second law does apply to open systems. Engineers use it all the time. You need an auxiliary device to allow a localized decrease in entropy.
Thus, according to your voodoo thermodynamics, hot things never cool down without an auxiliary device.
As for investigating the details of changes in yeast, I'm sure Matt can fill you in even though he's just a sloppy non-IDist... ![[Smile]](smile.gif)
[ 16. March 2003, 04:34: Message edited by: yersinia ]
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Carl
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posted 22. March 2003 23:57
(I started a reply and lost it - ?????)
Kyle7, I was impressed with your thread.
I would like my thread to focus on the fossil and DNA evidence, and the competing paradigms of Darwin and ID per my proposal. I see much discussion on IC, SLoT, and other topics, but nothing on what this thread covers.
This topic was closed because of combative attitude and getting off topic. I would like it to continue.
The yeast falls well within the microevolution, IMO. No matter how many of such microevolutionary changes occur, it will still be yeast. Macroevolution is simultaneous changes in DNA, not sequential.
I lost my other post by jumping back to the thread - perhaps someone can tell me how to look around and still get back to my post. :-(
[ 23. March 2003, 00:04: Message edited by: Carl ]
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Frances
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posted 23. March 2003 13:16
Carl: The yeast falls well within the microevolution, IMO. No matter how many of such microevolutionary changes occur, it will still be yeast. Macroevolution is simultaneous changes in DNA, not sequential.
An interesting definition of macroevolution. Where did you get the notion that these changes have to be simultaneous? Why should macroevolution be simultaneous and what evidence supports this notion? Perhaps an interesting topic for a new thread?
Kyle: Frances,
The second law does apply to open systems. Engineers use it all the time. You need an auxiliary device to allow a localized decrease in entropy. This auxiliary device must have all the mechanisms to allow the specified application of energy. A life-form has all the information in the genome that specifies the boundary conditions and the detailed processes to construct the life-from. However, when naturalists try to use NeoDarwinism to explain the development of new systems, they run into problems with the Second Law of Thermodynamics because they lack an auxiliary device that specifies the precise application of energy in the construction of the new system. The stochastic nature of the Darwinian mechanism does not allow the specification needed for new systems to develop.
And yet real experiments as well as simulations show quite the contrary. Not surprisingly since for open systems it is exactly the selection which causes the link between the environment and the genome. The auxiliary device is life itself which propagates with the survival rate being determined through a mutual information component between the genome and the environment. As shown by Adami it is this correlation betwen genome and environment which 'transports' the information from the environment into the genome. But it comes at an incredible cost, not surprisingly, since it requires the death of many organisms for every bit of information.
So I wonder if Kyle can present us with some actual data that show these problems neo-Darwinists run into dealing with the SLOT since as far as I can tell scientists have dealt quite well with the SLOT and found that the SLOT rather than being a limitation on evolution seems to be instrumental.
Evolution of Biological Complexity by Christoph Adami et al
quote:
In order to make a case for or against a trend in the evolution of complexity in biological evolution, complexity needs to be both rigorously defined and measurable. A recent information-theoretic (but intuitively evident) definition identifies genomic complexity with the amount of information a sequence stores about its environment. We investigate the evolution of genomic complexity in populations of digital organisms and monitor in detail the evolutionary transitions that increase complexity. We show that because natural selection forces genomes to behave as a natural ``Maxwell Demon'', within a fixed environment genomic complexity is forced to increase.
Or check out Adami's lectures which argue that "How natural selection behaves like a Maxwell Demon (selective measurements) so that the amount of information stored in genes can only increase. How this law can be violated. Evidence for this mechanism in digital organisms. How to correct for epistasis in the measurement of complexity. The role of co-evolution."
[ 23. March 2003, 13:25: Message edited by: Frances ]
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Carl
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posted 23. March 2003 22:10
Frances:
quote:
An interesting definition of macroevolution. Where did you get the notion that these changes have to be simultaneous? Why should macroevolution be simultaneous and what evidence supports this notion? Perhaps an interesting topic for a new thread?
This is a basic part of my proposal, integral to this thread. The fossil record overwhelmingly shows stasis, with no record of the changes. If macroevolution took thousands of years, as it would take at the rate of microevolution, there would surely be fossils showing such someplace. I recognize how sparse the fossil record is, and the difficulty in finding precise information, but with all the fossils that have been studied there should surely be some finds of partial macroevolution. They are not found!
Problems with the fossil record as proposed by Darwin:
The long periods of stasis are counter-intuitive. What process can prevent expression of mutations for millions of years, then force rapid change in some short but unspecified period of time? Close investigation of environment fails to provide that as a reason. In my proposal, the long periods of stasis are mandated, and the macroevolution happens within a single generation. I expect DNA to provide the proof when developmental biologists finally find out which genes determine the phenotype of organisms.
Random mutations would send an organism in many different directions. There should be many macroevolutionary variation to every species if random mutations are responsible for macroevolution. Darwin, in the only chart in ...Origin..., indicated many dead-end variations at each proposed speciation.
The sequence from theropod dinosaur to bird shows single-minded progression over several speciations, with several necessary bird-like changes in each speciation. The only way I can account for such a sequence is with design. Random processes should produce many false sidelines.
Macroevolution makes many major changes in an organism. For example, if the tooth becomes larger, it requires a different jaw which requires changes in skull, and the heavier head requires a different mechanism to support it, which also requires changes in the support mechanism of the legs and other associated characters. Organisms are never found with mismatched parts, which would indicate that once speciation begins it goes to completion, which means all parts are modified before any fossil is made. A more understandable change would be from knuckle walking to upright stance - study of the pelvis and legs indicates how walking was done, and it impacts most skeletal systems of the organism. It cannot be done in pieces - fitness of a partial change would be drastically reduced, and it could not survive over the proposed tens of thousands of years necessary for all the required DNA changes to be made.
I would like to see a detailed proposal of how DNA bases could be changed one at a time (or even by moving of sections of DNA) to accomplish the above problems. I cannot find any detailed proposal at all of how Darwin would propose such changes.
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Frances
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posted 23. March 2003 22:41
Carl: This is a basic part of my proposal, integral to this thread. The fossil record overwhelmingly shows stasis, with no record of the changes. If macroevolution took thousands of years, as it would take at the rate of microevolution, there would surely be fossils showing such someplace. I recognize how sparse the fossil record is, and the difficulty in finding precise information, but with all the fossils that have been studied there should surely be some finds of partial macroevolution. They are not found!
Perhaps you are not too familiar with the actual fossil records? I cannot fault you for this since paleontology is a very specialized science but a simple cursory search may help explain the confusion of stasis/evolution. In fact as evolutionary models have shown, stasis seems to be an intricate part of evolution itself.
An example of a beautiful transitional series from reptile to mammals 
You as "The long periods of stasis are counter-intuitive. What process can prevent expression of mutations for millions of years, then force rapid change in some short but unspecified period of time?" and the answer is very simple: Statis are periods in which mutations are mainly neutral and organisms 'search' in sequence space for mutations which may be beneficial. This feature has been shown in exquisite detail in RNA where large neutral networks can be found throughout sequence space and most other common structures can be found in close proximity.
Random mutations alone would send organisms off into many different directions that's why selection is an essential component.
Carl: The only way I can account for such a sequence is with design. Random processes should produce many false sidelines.
But evolution is not random thus while you may only be able to account for the observations by appealing to some form of design which seems to not explain anything, science has in fact looked at these observations and found some very plausible explanations.
Carl: I would like to see a detailed proposal of how DNA bases could be changed one at a time (or even by moving of sections of DNA) to accomplish the above problems. I cannot find any detailed proposal at all of how Darwin would propose such changes.
Darwin was not really aware of DNA so it should not come as a surprise that Darwin does not address these details. But as I said, check out the thread on RNA for instance to see how science approaches these questions in a very methodological manner and seems to have proposed plausible explanations for these observations.
[ 24. March 2003, 07:26: Message edited by: Moderator ]
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Carl
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posted 27. March 2003 01:06
Frances wrote:
<<Perhaps you are not too familiar with the actual fossil records? I cannot fault you for this since paleontology is a very specialized science but a simple cursory search may help explain the confusion of stasis/evolution. In fact as evolutionary models have shown, stasis seems to be an intricate part of evolution itself.
An example of a beautiful transitional series from reptile to mammals <snip> >>
That is a nice sequence of separate species. But we were discussing species that were only partly separate. Each one of the species you show were in stasis for probably at least a million years, then quickly (?) changed to a successor species.
DNA studies have shown that random mutations occur at apporximately the same rate all the time. For man it is approximately one mutation per person per year, spread out among the 3 billion bases. Some systems are highly conserved, and evidently reject the mutations, but the non-coding DNA shows just how much change continually occurs. So how do the species reject such mutations during stasis, then accept them during the speciation period (and just how long is thst speciation period, until mutations are again rejected?) Mayr says that 'purifying selection' reject the mutations, while other biologists claim that the mutations build up without being expressed so that when a change in environment occurs change will come quickly. I see major problems with either theory, and no evidence for either.
Frances
<<Statis are periods in which mutations are mainly neutral and organisms 'search' in sequence space for mutations which may be beneficial. >>
Then what process changes the character of the presumably random mutations to change their character for millions of years, then change it back for the short period of change? Is there any evidence for such a proposal?
Frances
<<Random mutations alone would send organisms off into many different directions that's why selection is an essential component.>>
Of course it should go in many different directions. So what evidence is there that it does not? Selection cannot prevent mutation, all it can do is act on what is presented.
Frances
<<But evolution is not random thus while you may only be able to account for the observations by appealing to some form of design which seems to not explain anything, science has in fact looked at these observations and found some very plausible explanations.>>
I have looked at the 'plausible' explanations of science, and am not very impressed. I keep looking for the evidence to back up the plausibles. IMO, the plausible explanations only mean something if you want to believe them. Without evidence they are just hopeful comments.
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Carl
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posted 28. March 2003 22:24
Random mutation thoughts.
Since the discovery of DNA, many approaches have been made to try to understand the development of species. It has been noted that random mutations occur at regular rates for the most part, and this has been called a DNA clock. Some biological compounds, such as those that provide energy to life, are highly conserved. As I understand it, every lifeform - animal, plant or microbe (with maybe some rare exceptions)- uses the same energy system. Some parts of the genome are not used, and changes there are not eliminated, and it is those parts that give the information for the DNA clock. In human the DNA clock is very close (within an order of magnitude) to one change per human genome per year. As only 3 percent of the human genome is used, that means that only 30 mutations in a thousand have a possibility of affecting the genome. About 1/3 of those would fall in the DNA bases that have no effect in specifying the amino acid building block, and most of the changes in working DNA are deleterious and do not survive. I estimate (no one else will, that I have seen) that one mutation in 1000 in the working DNA will survive, either neutral or advantageous to the organism.
In the sequence of reptiles to mammals shown in this thread, it is obvious that each organism in the sequence is different from it's predecessor and it's successor. Complexity theory requires more descriptors for more complex forms. The differences between steps must be described within the DNA, but that application of DNA has eluded the developmental biologists according to what I have read. Thus any estimate of the amount of difference between such steps has to be mostly guesswork. I believe that at least 1000 bases must be different between each stage. Going back to the one effective mutation per 1000 years from the previous paragraph, 1000 bases would take 1 million years to integrate if every random change was the correct one. I recognize that there are other processes that evolution uses, but they are considered much rarer than random mutation. The problem is that the fossil record shows no change at all during the periods of stasis, and gives no time for the changes to take place. If we take the 40,000 year figure that Gould proposed (pulled out of thin air) for species to change, that would only be 40 base changes. However, there is no fossil evidence for such time, and 40 changes would be hard pressed to describe all the changes necessary to become a different species. Random mutations are not expected to go to the precise places needed (and there may not even be a step-by-step sequence of base replacements to get from the old to the new gene configuration.)
These figures make any support for Darwin's proposal difficult from the fossil record.
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Frances
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posted 29. March 2003 15:09
Carl asserts that the excellent series of transitional fossils from reptile to mammal shows separate species. I do not understand why this is a problem? Speciation is a well understood concept and has even been observed in our lifetime. Carl suggests that these 'species' were in stasis for probably at least a million years and then changed quickly to their succesor species. While such speculation may be interesting it misses that intermediate forms of the reptile to mammal transition can be found.
Carl then wonders about the processes that change the nature of the mutations but as I have argued, the nature of the mutations is determined by the phenotype to genotype mapping. It has been found that there are few common secondary (RNA) or protein (DNA) structures and many very uncommon. It furthermore has been found that these common structures are prevalent throughout sequence space and well connected to other common structures. At certain moments when mutations may have to cross what would have been a chasm, they can now cross since neutral mutations are so common. It is the structure of the genotype/phenotype space which determines the nature of the mutations, combined of course with the environment.
No change in process but a change in the genotype phemotype space may explain the existence of statis followed by fast change. Carl wonders why mutations would not direct organisms in random directions but as I have stated, it does and it is selection which culls from these random directions the ones that are most succesful. Selection cannot prevent mutation but it can surely determine which mutations are allowed to continue and which ones are 'dead ends'.
Since Carl states that he has looked at plausible explanations of science, it might be helpful if Carl can provide us with some examples. We can then determine if there is supporting evidence for these scenarios.
As Carl stated, without evidence these are just hopeful comments. Interestingly enough that is a two sided sword since it applies equally well to his speculations.
Carl also seems to jump from a conclusion of different to 'more complex' "In the sequence of reptiles to mammals shown in this thread, it is obvious that each organism in the sequence is different from it's predecessor and it's successor. Complexity theory requires more descriptors for more complex forms." but fails to show that difference between predecessor and successor increase complexity. But as has been shown evolutionary processes seem to be quite able to increase complexity in the genome.
Furthermore rather than pursue Carl's strawman 'evolutionary' proposal, we may far more benefit from actual examples of such proposals and see if there is any support for the Darwinian theory from the fossil record. One of the obvious problems with Carl's scenario is that even within the same species there are likely far more than 1000 bases difference in the DNA.
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Carl
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posted 29. March 2003 22:01
Frances wrote:
quote:
Carl asserts that the excellent series of transitional fossils from reptile to mammal shows separate species. I do not understand why this is a problem? Speciation is a well understood concept and has even been observed in our lifetime. Carl suggests that these 'species' were in stasis for probably at least a million years and then changed quickly to their succesor species. While such speculation may be interesting it misses that intermediate forms of the reptile to mammal transition can be found.
The problem is your labeling of such species as 'intermediate forms', like there is something different in the species you have shown and 'normal' species. Close examination of the fossil record shows that species remain the same from it's earliest identification to the latest time it is found, with very few exceptions. Gould's big book on 'The Structure of Evolutionary Theory' has some excellent information on the fossil record. The observed stasis is not speculation, but and observed fact. Geologists, who were often paleontologists as well, have used species as markers for years, and when biologists trained as paleontologists closely examined the fossil record they had to agree. Two different studies of fossils have shown the periods of stasis to be 1 million to 3 million years on the average. As the change from one species to another is not recorded in the fossils presently available, there is no time period that can be given for the speciation process.
quote:
Carl wonders why mutations would not direct organisms in random directions but as I have stated, it does and it is selection which culls from these random directions the ones that are most succesful. Selection cannot prevent mutation but it can surely determine which mutations are allowed to continue and which ones are 'dead ends'.
If mutations really go in random directions, then at least some of them should be succesful in the short term. Darwin, in the only drawing in his book, showed several branches at each step, only one or two of which were succesful in the long run. Yet we consistently see linear series of species with no record at all of failed offshoots at each speciation.
quote:
Since Carl states that he has looked at plausible explanations of science, it might be helpful if Carl can provide us with some examples. We can then determine if there is supporting evidence for these scenarios.
Here is one from your post: "No change in process but a change in the genotype phemotype space may explain the existence of statis followed by fast change." The description of how evolution works is filled with such speculation, presented as plausible explanations. I have seen biologists present a plausible explanation to counter such well-thought-out problems as Behe presented, and claiming from those plausible explanations that Behe is totally wrong.
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As Carl stated, without evidence these are just hopeful comments. Interestingly enough that is a two sided sword since it applies equally well to his speculations.
Absolutely.
quote:
Carl also seems to jump from a conclusion of different to 'more complex' "
I was not trying to indicate that one of the species you presented was more complex than another, but just that each one is complex and requires many descriptors to completely specify it. Adjacent species will have many descriptors different, to adequately describe each one. As the descriptors available are DNA bases, there has to be many different bases.
quote:
One of the obvious problems with Carl's scenario is that even within the same species there are likely far more than 1000 bases difference in the DNA.
There is obviously much variation within species, far more than 1000 bases as you state. But the PAX6 gene, for example, which helps initiate the eye, is almost identical in drosophila, mouse and human. For purposes of my proposal, the genes that need to be identified are those that cause the formation of the teeth, or jaw, or skull that are different in successive species in the sequence shown above. Science has identified many SNPs (Single Nucleotide Polymorphisms) that seem to provide some of the variation noted between individuals within a species. In my proposal the SNPs remain the same in a new speciation, with only the necessary changes (as noted in the skeleton, primarily) being made in the DNA. Once science has determined which genes describe the tooth or skull, similar genes from related species can be compared to determine how many bases have been modified.
quote:
Furthermore rather than pursue Carl's strawman 'evolutionary' proposal, we may far more benefit from actual examples of such proposals and see if there is any support for the Darwinian theory from the fossil record.
When you really understand my proposal you will see that it is based upon solid evidence. But I would welcome a study of actual examples. I am not sure what you are referring to. Could you please amplify the suggestion?
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yersinia
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posted 29. March 2003 22:29
Just picking one severe error out of many in Carl's posts:
quote:
If mutations really go in random directions, then at least some of them should be succesful in the short term. Darwin, in the only drawing in his book, showed several branches at each step, only one or two of which were succesful in the long run. Yet we consistently see linear series of species with no record at all of failed offshoots at each speciation.
No we don't. I'd be surprised if you can give an example that spans more than a few species. The dominant pattern is the "bush" with lots of dead ends. E.g., fossil horses are a famous example of this:
Fossil Horses FAQ index
A greatly simplified horse family tree:
code:
2My Old & New World Equus
\ | /
\ | /
4My Hippidion Equus Stylohipparion
| | Neohipparion Hipparion Cormohipparion
| | Astrohippus | | |
| | Pliohippus ---------------------------
12My Dinohippus Calippus \ | /
| | Pseudhipparion \ | /
| | | |
------------------------------------------- Sinohippus
15My \ | / |
\ | / Megahippus |
17My Merychippus | |
| Anchitherium Hypohippus
| | |
23My Parahippus Anchitherium Archeohippus
| | |
(Kalobatippus?)-----------------------------------------
25My \ | /
\ | /
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35My |
Miohippus Mesohippus
| |
40My Mesohippus
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45My Paleotherium |
| Epihippus
| |
Propalaeotherium | Haplohippus
| | |
50My Pachynolophus | Orohippus
| | |
| | |
------------------------------
\ | /
\ | /
55My Hyracotherium
The horses also contradict your wild statements regarding species-species transitions "always" being abrupt, because with horses (as well as many other mammals), sometimes they are (paleontologically) abrupt, but sometimes they are quite gradual.
Some of the conclusions:
quote:
Horse species were constantly branching off the "evolutionary tree" and evolving along various unrelated routes. There's no discernable "straight line" of horse evolution. Many horse species were usually present at the same time, with various numbers of toes, adapted to various different diets. In other words, horse evolution had no inherent direction. We only have the impression of straight-line evolution because only one genus happens to still be alive, which deceives some people into thinking that that one genus was somehow the "target" of all the evolution. Instead, that one genus is merely the last surviving branch of a once mighty and sprawling "bush".
The view of equine evolution as a complex bush with many contemporary species has been around for several decades, and is commonly recounted in modern biology and evolution textbooks.
...however Carl seems to be unaware of it.
Regarding the special creation of species, the FAQ discusses the problems the horse record presents; "God" is referred to but the conclusions apply equally well to any interventionist designer:
quote:
A Question for Creationists: Creationists who wish to deny the evidence of horse evolution should careful consider this: how else can you explain the sequence of horse fossils? Even if creationists insist on ignoring the transitional fossils (many of which have been found), again, how can the unmistakable sequence of these fossils be explained? Did God create Hyracotherium, then kill off Hyracotherium and create some Hyracotherium-Orohippus intermediates, then kill off the intermediates and create Orohippus, then kill off Orohippus and create Epihippus, then allow Epihippus to "microevolve" into Duchesnehippus, then kill off Duchesnehippus and create Mesohippus, then create some Mesohippus-Miohippus intermediates, then create Miohippus, then kill off Mesohippus, etc.....each species coincidentally similar to the species that came just before and came just after?
Just to emphasize that Carl is contradicted not only by horses, he should read Transitional Fossils FAQ
Carl's population genetics is also erroneous but let's deal with the fossils first.
yersinia
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Frances
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posted 30. March 2003 00:32
Carl: "Close examination of the fossil record shows that species remain the same from it's earliest identification to the latest time it is found, with very few exceptions."
I have shown various examples that show that this is erroneous. I do not believe that Carl's portrayal of the fossil record is in line with the reality of the fossil record. The moderator deleted most of my previous links thus I will not repeat them.
Carl: I was not trying to indicate that one of the species you presented was more complex than another, but just that each one is complex and requires many descriptors to completely specify it. Adjacent species will have many descriptors different, to adequately describe each one. As the descriptors available are DNA bases, there has to be many different bases.
Even within the same species there are many different DNA bases. The reason why the Pax gene is well conserved is because of the fact that it seems to be an essential bauplan gene.
Perhaps Carl could share with us his solid evidence?
He mentioned before that he had looked at plausible explanations of science and found them to be lacking. Perhaps Carl could share with us a few of those examples for us to discuss?
As others also have shown species species transitions need not be abrupt although at the resolution of the fossil record one may not always be able to discern all the changes.
Carl: The problem is your labeling of such species as 'intermediate forms', like there is something different in the species you have shown and 'normal' species.
Nope, transitional/intermediate forms are descriptors used to describe the nature of these fossils. Nothing different from 'normal' species just that in this case these fossils show a gradual change from reptile to mammal.
As I have shown, stasis is not only expected from the genotype-phenotype mapping but that does not mean that gradual changes cannot and do not happen. The fossil record has many exquisite examples of such.
Or in the words of Gould
quote:
“The anatomical transition from reptiles to mammals is particularly well documented in the key anatomical change of jaw articulation to hearing bones. Only one bone, called the dentary, builds the mammalian jaw, while reptiles retain several small bones in the rear portion of the jaw. We can trace, through a lovely sequence of intermediates, the reduction of these small reptilian bones, and their eventual disappearance or exclusion from the jaw, including the remarkable passage of the reptilian articulation bones into the mammalian middle ear (where they became our malleus and incus, or hammer and anvil). We have even found the transitional form that creationists often proclaim inconceivable in theory — for how can jawbones become ear bones if intermediaries must live with an unhinged jaw before the new joint forms? The transitional species maintains a double jaw joint, with both the old articulation of reptiles (quadrate to articular bones) and the new connection of mammals (squamosal to dentary) already in place! Thus, one joint could be lost, with passage of its bones into the ear, while the other articulation continued to guarantee a properly hinged jaw. Still, our creationist incubi, who would never let facts spoil a favorite argument, refuse to yield, and continue to assert the absence of all transitional forms by ignoring those that have been found, and continuing to taunt us with admittedly frequent examples of absence.”
— "Hooking Leviathan by Its Past," Dinosaur in a Haystack: Reflections in Natural History, New York: Crown Trade Paperbacks, 1997, pp. 360-361.
Gould on gradualism and Darwinism
quote:
“The modern theory of evolution does not require gradual change. It in fact, the operation of Darwinian processes should yield exactly what we see in the fossil record. It is gradualism that we must reject, not Darwinism. […] Eldredge and I believe that speciation is responsible for almost all evolutionary change. Moreover, the way in which it occurs virtually guarantees that sudden appearance and stasis shall dominate the fossil record. All major theories of speciation maintain that splitting takes place rapidly in very small populations. The theory of geographic, or allopatric, speciation is preferred by most evolutionists for most situations (allopatric means ‘in another place’). A new species can arise when a small segment of the ancestral population is isolated at the periphery of the ancestral range. Large, stable central populations exert a strong homogenizing influence. New and favorable mutations are diluted by the sheer bulk of the population through which they must spread. They may build slowly in frequency, but changing environments usually cancel their selective value long before they reach fixation. Thus, phyletic transformation in large populations should be very rare — as the fossil record proclaims. But small, peripherally isolated groups are cut off from their parental stock. They live as tiny populations in geographic corners of the ancestral range. Selective pressures are usually intense because peripheries mark the edge of ecological tolerance for ancestral forms. Favorable variations spread quickly. Small peripheral isolates are a laboratory of evolutionary change.
“What should the fossil record include if most evolution occurs by speciation in peripheral isolates? Species should be static through their range because our fossils are the remains of large central populations. In any local area inhabited by ancestors, a descendant species should appear suddenly by migration from the peripheral region in which it evolved. In the peripheral region itself, we might find direct evidence of speciation, but such good fortune would be rare indeed because the event occurs so rapidly in such a small population. Thus, the fossil record is a faithful rendering of what evolutionary theory predicts, not a pitiful vestige of a once bountiful tale.”
— "The Episodic Nature of Evolutionary Change," The Panda's Thumb: Reflections in Natural History, New York: W. W. Norton & Company, 1980, pp. 182-184.
Both from this source
Carl: If mutations really go in random directions, then at least some of them should be succesful in the short term. Darwin, in the only drawing in his book, showed several branches at each step, only one or two of which were succesful in the long run. Yet we consistently see linear series of species with no record at all of failed offshoots at each speciation.
It seems once again that Carl may be unfamiliar with the fossil record and what to expect. What exactly does Carl propose with short term successes of random mutations? Would such changes lead to immediate speciation ? It would be helpful if Carl could describe his model in more detail and explain to us how it relates to evolution.
[ 30. March 2003, 01:01: Message edited by: Frances ]
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Carl
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posted 30. March 2003 22:14
Excellent reply, Yersinia
quote:
No we don't. I'd be surprised if you can give an example that spans more than a few species. The dominant pattern is the "bush" with lots of dead ends. E.g., fossil horses are a famous example of this:
I was thinking of the horse 'bush' when I wrote my post, but could not think of how to include that information without cluttering up what I was trying to say. Each species in the horse bush was successful enough to persist for as long as most species remain. But Darwin clearly indicated that there should be numerous branches that should die out in shorter times because they could not compete. Natural selection works on very small differences as well as on larger differences, and the smaller the difference the longer the poorer species will persist. The fossil record probably would not pick up species that would only persist for a few thousand years, but it should pick up those that would last 100,000 years. There seems to be a lack of such short lived species, even though random mutations should produce many more unsuccessful species than it does successful ones.
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The horses also contradict your wild statements regarding species-species transitions "always" being abrupt, because with horses (as well as many other mammals), sometimes they are (paleontologically) abrupt, but sometimes they are quite gradual.
Here we have to define what we mean by gradual. In geologic time, the various pre-horse species are gradual, as are the steps from reptile to mammal in the previous post. However, when talking about evolution by random mutation, which seems to be the major source of change in the fossil record, gradual has to mean single base changes in DNA. Gould has a different point of view than many biologists, but he is (was) an excellent paleontologist, and knows the fossil field as well as anyone I know. I have his big book, The Structure of Evolutionary Theory, and in that book he spends much time insisting that the fossil record overwhelmingly represents stasis. One instance of gradual (meaning a long time to change one species into another) speciation he attributed to hybridation, rather than mutation. Some of the few other examples of gradual change, when examined, indicate some process other than mutation for the change.
Your quote asks: "how can the unmistakable sequence of these fossils be explained?"
One answer can be found in another quote:
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Many horse species were usually present at the same time, with various numbers of toes, adapted to various different diets.
Suppose there is a designer for each species. IOW, the head designer has at his disposal almost unlimited help. There is also a fixed goal, and the intermediate goals might be flexible with regard to time and what the intermediates look like. (Here 'intermediate' refers to any species between bacteria and man.) The various designers assigned to the horse clan have different niches to fill, and modify the designs appropriately, keeping in mind that one line has to end up with the draft and riding animal that equus is. I see a bush as an excellent result.
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Just to emphasize that Carl is contradicted not only by horses, he should read Transitional Fossils FAQ
I really appreciate the excellent FAQs on TO. I browsed them years ago, and enjoyed them very much.
Frances wrote:
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Carl: "Close examination of the fossil record shows that species remain the same from it's earliest identification to the latest time it is found, with very few exceptions."
I have shown various examples that show that this is erroneous. I do not believe that Carl's portrayal of the fossil record is in line with the reality of the fossil record. The moderator deleted most of my previous links thus I will not repeat them.
I would like to see some of the links that disagree with Gould. I have much confidence in his knowledge, but recognize that he could be biased. Perhaps the moderator would allow one or two good references.
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He mentioned before that he had looked at plausible explanations of science and found them to be lacking. Perhaps Carl could share with us a few of those examples for us to discuss?
Did you miss the plausible explanation you made that I pointed out to you in my previous post?
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As others also have shown species species transitions need not be abrupt although at the resolution of the fossil record one may not always be able to discern all the changes.
I see this statement, explaining why the fossil record does not yield what Darwin expected, as a plausible explanation. Some plausible explanations are more plausible than others, and the sparcity of the fossil record is real, but with the millions of speciations you would think that every once in a while a fossil that is halfway between two established species would be found. I believe that if such were found, the finder might get a nobel prize for finding proof for Darwin's idea of speciation. Instead we see more steps added to the ladder of evolution, with each step being discrete and enough different from those on each side to preclude mixing them up. My proposal requires small, discrete steps - not gradual (see my definition above) steps nor giant steps. The change in jawbone configuration that led to mammal ear bones is exactly the type of steps my proposal requires. The horse bush is another example of the same.
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As I have shown, stasis is not only expected from the genotype-phenotype mapping but that does not mean that gradual changes cannot and do not happen. The fossil record has many exquisite examples of such.
The recent study of the finches on Galapagos Island is an excellent example of how gradual changes happen, and how they respond to environmental change. It covered about 20 years, and followed changes during drought and rainy periods. The population crashed during terrible drought, and could have gone extince had it lasted longer. During good times the population soared. The makeup of the population varied according to the food supply available. Beak size varied, as did proportion of birds in adjacent species. But all these changes were from the already existing variation built in the species. Had they not had variation built in, some species surely would have perished, but the variation gave enough robustness to the species that they survived. But there was no evidence of mutation, hence heritable change/evolution was not a part of the study.
From Gould's quote:
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All major theories of speciation maintain that splitting takes place rapidly in very small populations. The theory of geographic, or allopatric, speciation is preferred by most evolutionists for most situations (allopatric means ‘in another place’). A new species can arise when a small segment of the ancestral population is isolated at the periphery of the ancestral range.
I had not seen this statement before, but have seen similar ones from others. I believe that Mayr was the originator of this basic idea, but he did not amplify it as much as Gould does here. You will note that Gould correctly labels this as a theory. He does not list any evidence to back up this idea, and when I try to visualize the details I come up with problems. For example, Mayr contends that a large group has 'purifying selection' to decrease the variation within the species, while another biologist insists that stasis is used to increase the diversity of the species so that when a small group separates it already has enough variation to rapidly speciate. ?????
Is there any evidence for either view?
How 'small' is the group that separates from the main body? I have not seen any proposal.
How long is the 'quick' speciation? Gould pulled 40,000 years out of the hat, but I doubt there is any fossil support for that figure. I have seen studies of the persistence of fossil species, one said 1 million years and another said 3 million years on the average. But no one has tried to determine how much time there is between species, that I have seen. Perhaps the studies of the persistence of species could also address the between-species times, but I have not seen the original work.
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In any local area inhabited by ancestors, a descendant species should appear suddenly by migration from the peripheral region in which it evolved.
Gould again speculating. I wonder how long two almost evenly matched species would exist side by side? Some of the changes from one species to the successor species seem to provide very little, if any, survival advantage. If a small group in some periphal area changed, and then spread over the range of the earlier group, it should take maybe a million years to get rid of the vestiges of the original species. Yet oil company geologists and others that need to date rock formations use fossil species to date them. The same fossils area in the same strata all over the world. That is a very large area to be 'conquored' by a successor species - you would expect that the time scales determined from fossils would have to be adjusted according to the distance from where the speciation originated. I am not aware of any efforts to make such adjustments, which could be taken as evidence that the speciation occured at the same time over the range of the species.
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It seems once again that Carl may be unfamiliar with the fossil record and what to expect. What exactly does Carl propose with short term successes of random mutations? Would such changes lead to immediate speciation ? It would be helpful if Carl could describe his model in more detail and explain to us how it relates to evolution.
Perhaps another explanation will clarify the proposal. I propose that macroevolution occurs in a single generation, by change in the required genes of each embryo born after some date. This would preserve the variation within the species, and would change the species within a single generation. Microevolution is a change of less than 10 bases at one time, usually only a single base. This happens all the time, at a rate that DNA analysis can determine. It seldom results in speciation, and very rarely does such a mutation happen in a base that causes major phenotypic change. Darwin was very perceptive to see this type of change. Unfortunately microevolution does not have the power to cause macroevolution.
You will note from one of my posts above how the evidence looks at mutation.
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yersinia
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Member # 324
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posted 31. March 2003 02:55
Carl,
There are so many misconceptions in your post that I rather despair that I can get anywhere. You seem to want individual mutational "steps" to be found in the fossil record. You must realize this is ridiculous, for both genetic (most traits, especially size etc., are continuous traits) and paleontological (basically only bones fossilize consistently) reasons.
You claim to have read the talk.origins transitional fossils FAQ, but you also claim that microevolution can't add up to macroevolution. You evidently missed bits such as this set of *gradual* transitions between *families* which is macroevolution in anyone's book:
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Krishtalka & Stucky (1985) documented smooth transitions in the common early Eocene artiodactyl genus Diacodexis. The fossil record for these animals is very good (literally hundreds of new specimens have been found in Colorado and Wyoming since the 1970's). Analysis of these specimens found gradual species-species transitions for every step of the following lineage, including the origination of three different familes: Diacodexis secans-primus is the first artiodactyl species known. Immediately a new group of animals split off that gave rise to the Wasatchia and Bunophorus genera (not further discussed by this particular paper). Meanwhile, the main lineage of D. s-primus continued, and became D. s-metsiacus. Two species split off from D. s-metsiacus: one was D. gracilis, the other was an as-yet-unnamed new species "Artiodactyla A", which gave rise to "Artiodactyla B"; these two were the first members of the new families Homacodontidae and Antiacodontidae. Meanwhile, D. s- metsiacus continued changing and became D. s-kelleyi. Another species forked off, D. minutus. Slightly later another species forked off, D. woltonensis, which apparently was the first member of the new family Leptochoeridae. Meanwhile, D. s-kelley continued changing and became D. s-secans. Some quotes from the paper: "A good fossil record, such as that of Diacodexis, flies major anagenetic change in the face of artificial [naming] conventions..." "Evolutionary change (both anagenesis and cladogenesis) among these artiodactyls appears to have been gradual, chronoclinal, and mosaic, involving an increase in the degree of expression and frequency of occurrence of derived morphologic features..." "...it appears that different taxa of artiodactyls -- in hindsight, the most primitive members of originating suborders, families, and subfamilies -- arose at different times from different lineage segments of the single species Diacodexis secans." The authors conclude: "Microevolutionary processes can account for both cladogenetic and anagenetic change among these artiodactyls; macroevolutionary processes are not called for."
Or how about this series, looks pretty gradual to me:
...I expect my Nobel prize in the morning, unless you can tell me which of these fossils belong to the same designed type as modern humans, and which are a different designed type.
Or did your multiple designers gradually work on all of these different models and finally pick just one and let the rest die off there, also?
Regarding punk eek, the major reason for thinking that speciation might occur in small peripheral populations are that (1) population genetics shows that small populations can change much more rapidly (new alleles are much easier to spread to fixation; and (2) peripheral populations are likely to experience novel environments that would drive new adaptations. It is still debatable whether this really is the major mechanism of speciation; the fossil record of e.g. mammals shows numerous examples of both PE and smooth transitions.
I could go on and on, but I won't.
But the one thing I did like about your post was that you actually stuck your neck out and proposed a design model -- in a word, the much criticized (on ISCID) Multiple-Designer Theory (MDT):
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Suppose there is a designer for each species. IOW, the head designer has at his disposal almost unlimited help. There is also a fixed goal, and the intermediate goals might be flexible with regard to time and what the intermediates look like. (Here 'intermediate' refers to any species between bacteria and man.) The various designers assigned to the horse clan have different niches to fill, and modify the designs appropriately, keeping in mind that one line has to end up with the draft and riding animal that equus is. I see a bush as an excellent result.
I see it as incredibly wasteful way to design something. Why bother with all the other horse species?
And, why didn't the Australians and native Americans have horses, if the point was to give humans handy beasts of burden? Why did zebras prove essentially undomesticatable, depriving Africans of these handy beasts? There are some decent answers to these questions based on natural processes, but on your design model these facts are inexplicable except by appeal to "the designer wanted it that way".
yersinia
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Frances
Member
Member # 169
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posted 31. March 2003 13:01
Carl: I would like to see some of the links that disagree with Gould. I have much confidence in his knowledge, but recognize that he could be biased. Perhaps the moderator would allow one or two good references.
I provided you with a link to Gould quotes for your perusal.
Other random comments
Carl: You will note that Gould correctly labels this as a theory. He does not list any evidence to back up this idea, and when I try to visualize the details I come up with problems.
In order to understand Gould's theory you need to do more than rely on a quote Carl. Are you familiar with the seminal papers by Eldredge and Gould on this topic?
Carl: Gould again speculating. I wonder how long two almost evenly matched species would exist side by side?
It is fascinating that Gould's claims are called speculative (despite the fact that there is more support for them than for Carl's 'speculative speculations').
Carls non sequitur strawman: I am not aware of any efforts to make such adjustments, which could be taken as evidence that the speciation occured at the same time over the range of the species.
It is fascinating how Carl seems to rely on building strawmen which seem to have little or no relationship to reality only to use them as support for his thesis.
And the best one of Carl's speculative claims: "Unfortunately microevolution does not have the power to cause macroevolution."
Carl has failed to show that many instances of microevolution cannot be considered macroevolution. Lacking any evidence of macroevolutionary changes in a single generation and presented with much evidence showing gradual change it seems that Carl's speculative ideas may have to be rejected as relevant.
As Yersinia comments "There are so many misconceptions in your posts that I despair that I can get anywhere.' Indeed I have the same feeling where Carl jumps from one quote to the other, grasping at bits of 'evidence' left and right helping to formulate a strawman or two only to be stricken down in the next paragraph.
it would be helpful if Carl were to read some of the relevant scientific papers on the concepts he seems to comment on such as Gould and Eldredge and punctuated equilibrium as well as the RNA papers by Schuster which show how microevolution happens at all the time and yet at some times there are instances of stasis while at other moments there are instances of gradual changes all because of the characteristics of the genotype-phenotype mapping. No need to appeal to hopeful monster mutations. Nevertheless if Carl can show evidence of such mutations then by all means.
Oh and one more
Carl: "However, when talking about evolution by random mutation, which seems to be the major source of change in the fossil record, gradual has to mean single base changes in DNA. Gould has a different point of view than many biologists, but he is (was) an excellent paleontologist, and knows the fossil field as well as anyone I know"
Carl seems to forget that evolution is not merely random mutation but also selection. But random mutation is not limited to point mutations either. Perhaps Carl is unaware of the various other mutations that may happen which are not limited to single base changes in DNA? Gould's views also are not that very different than many biologists. And indeed he knows his fossil field quite well which is why Gould should not be used to support the ideas of absence of gradualism in the fossil record.
That Gould finds that the fossil record shows much stasis does not negate that the fossil record also shows abrupt and gradual changes and in fact he complains how his comments seem to be taken to mean that no such gradual changes exist.
But rather than chasing an ever changing argument, correcting the many misconceptions I see, I would like to see Carl present some evidence for HIS viewpoint.
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RBH
Member
Member # 380
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posted 31. March 2003 22:27
yersinia wrote quote:
But the one thing I did like about your post was that you actually stuck your neck out and proposed a design model -- in a word, the much criticized (on ISCID) Multiple-Designer Theory (MDT)
Since it's before Carl's time on ISCID (or at least well before his registration on ISCID) here's a reference to Multiple Designers Theory for him.
RBH
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