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Author | Topic: IC & the Cambrian Explosion for Ahmad...cont.. | |||||||||||||||||||||||||||
Ahmad Inactive Member |
quote: I am going to use the examples of IC as the positive evidence. There are many examples of irreducible complexity which be found here. To pick one: Bacterial flagella.
Behe summarizes the structure of the bacterial flagellum in these terms: Some bacteria boast a marvelous swimming device, the flagellum, which has no counterpart in more complex cells. In 1973 it was discovered that some bacteria swim by rotating their flagella. So the bacterial flagellum acts as a rotary propellor -- in contrast to the cilium, which acts more like an oar. The structure of a flagellum is quite different from that of a cilium. The flagellum is a long, hairlike filament embedded in the cell membrane. The external filament consists of a single type of protein, called "flagellin." The flagellin filament is the paddle surface that contacts the the liquid during swimming. At the end of the flagellin filament near the surface of the cell, there is a bulge in the thickness of the flagellum. It is here that the filament attaches to the rotor drive. The attachment material is comprised of something called "hook protein." The filament of a bacterial flagellum, unlike a cilium, contains no motor protein; if it is broken off, the filament just floats stiffly in the water. Therefore the motor that rotates the filament-propellor must be located somewhere else. Experiments have demonstrated that it is located at the base of the flagellum, where electron microscopy shows several ring structures occur. The rotary nature of the flagellum has clear, unavoidable consequences ... (pp. 70-72) Behe concludes that such irreducibly complex systems were ultimately the result of intelligent design. (It should be pointed out that Behe has no objections to the concept of universal common ancestry as he is not a creationist himself. His objections to evolution are limited to the rejection of the neo-Darwinian mechanism as a sufficient explanation for the origin of all biological systems.) So there you have it. A positive evidence from the example of bacterial flagella and its apparent irreducible complexity. Ofcourse there are many... but this should suffice to serve as the positive evidence.
quote: As I said before, the abrupt appearance of almost all animal phyla, save the bryozoans, including some very weird and highly complex ones (trilobites, Ottoia etc which are now said to be extinct) in a geologically short period of time (~5-10 million years) poses a surmountable amount of problems for the ToE to explain. In fact, investigations done in the Yunnan province now reduces the period of time taken for the appearance of organisms to 2 YEARS!! I would call them mammoth hurdles for evolution to explain and give a descriptive valid evidence for the occurence of evolution in the cambrian era.
quote: I have several times outlined my own assertion and explanation for the cambrian explosion. Cambrian explosion is strong evidence for creation. Creation theory offers reasonable explanations for both the Cambrian Explosion and the origin and ubiquity of the genetic code that evolution can't. The taxonomic diversity seen in the Cambrian Explosion may be simply the result of preservation of various communities of marine organisms living on or near the floor of the sea. The basis for the association of the fossils is ecological rather than genealogical. The absence of ancestors in the underlying strata is not due to a faulty fossil record, but reflects separate origins of the various groups. This proposition applies whether one reads the fossil record as extended history or as complex catastrophe. Design may be the best explanation for the origin and ubiquity of the genetic code. Common design seems eminently reasonable as an explanation of similar features in organisms that appear genealogically unlinked. That is my opinion about it. Regards,Ahmad
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Ahmad Inactive Member |
Mark, this may be my last post for the weekend, as I will be away for a while. So don't expect any immediate response
quote: Ok, do it like Primordial egg did. Give me the criterias or the possible potential pathways by which IC systems could have evolved and I will put some IC examples to the test to see if the proposed evolutionary pathway could have evolved the IC system. Fair enough? If not, then tell me.. what will it take me to prove, in your opinion, that IC systems couldn't have evolved and I'll chalk out a response.
quote: To begin with, I don't understand your question. If you could be more clear... it would be helpful for me to respond since you want me to be more specific. I will make an attempt to answer nonetheless, as I have understood it. I think it ties at the phyla level since most of the animal phyla made their first appearances during that time. Thats all I can say for now... unless you can be more specific Regards,Ahmad
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Ahmad Inactive Member |
quote: Yes, Yes I can and I have many a times. But you dismiss my response by saying its an argument from incredulity when its not. I will reiterate once again and this time in the words of Behe: "By irreducible complexity I mean a single system which is composed of several interacting parts that contribute to the basic function, and where the removal of any one of the parts causes the system to effectively cease functioning. An irreducibly complex system cannot be produced directly by slight, successive modifications of a precursor system, since any precursor to an irreducibly complex system is by definition nonfunctional. Since natural selection requires a function to select, an irreducibly complex biological system, if there is such a thing, would have to arise as an integrated unit for natural selection to have anything to act on. It is almost universally conceded that such a sudden event would be irreconcilable with the gradualism Darwin envisioned." Now thats the basic definition backed up by the biological examples that are IC, as I have shown in previous post. If you disagree, don't just dismiss it by saying its an argument from incredulity but point it out to me exactly where the incredulity lies. By definition, as well as by numerous biological examples... its evident that any system that is IC (aka Behe's definition) could not have evolved by the serial direct darwinian evolution. If you disagree, provide YOUR argument or pick faults from mine and I will respond. I have done my part.
quote: I am not updated with this "multipurpose genome"... never heard of it, but it seems interesting. In my opinion, I favor the polyphyletic explanation. Yes I am well-aware of that this taxon is recognised invalid in the cladistic taxonomies but nonetheless, it can well explain the cambrian explosion adequately. Polyphyly implies that the genetic code has multiple independent origins, and is not the result of common ancestry as the darwinian monophyletic tree depicts. This suggests the concept of similarity by common design. Design may be the best explanation for the origin and ubiquity of the genetic code, as I have said before. Common design seems eminently reasonable as an explanation of similar features in organisms that appear genealogically unlinked (for eg - try comparing the trilobites with ottoia and see if you can find any morphological similarity) Perhaps polyphyly is an idea that deserves greater consideration by the scientific community. The idea has been mentioned a few times as I remember, but does not seem to have been seriously discussed within the mainstream scientific community. One counterargument against polyphyly, that I know of, is that biomolecular similarities indicate common ancestry and monophyly. For example, the genetic code and metabolic enzymes are similar in nearly all living organisms. However, there are significant differences in the details of the cellular processes in different groups of organisms.(The phylogeny of prokaryotes. Science 209:457-463.). I hope the explanation suffices.
quote: Now remember, it is not quantity that made their appearances thats significant (although there is a high quantity too) but the quality of the organisms taking in account the widely varying anatomical designs, or novel body plans. When almost all the animal phylas made their appearance at that time, save bryozoans, why is it that you ask for the sub-taxas? Is there a "Law of creation" that you know of that states that God should create all living organisms at the same time? He gave rise to the phylas... family, genera, and species took their toll, may be sometime later. But how does that invalidate my claim? This what my actual argument against evolution and for creation really is: How is it that evolution predicts the gradual step-by-step cumulative progression of complexity in organisms while the cambrian explosion turns out to be diametrically the opposite? The wide mosaic variety of living organisms (that comprised almost all the animal phylas) with an equally highly complex anatomical design of the novel body plans, made their appearance more than 500 years during an explosion that lasted only ~5-10 million years. What alternative does evolution suggest to explain this explosion? Furthermore, some Chinese scientists even believe that time period for the cambrian explosion is more like 2-3 million years (Chinese National Geography 467 Sept 1999)!! Believe it or not, but this big bang has really blown the socks of evolution and I reckon they will have one hell of a time justifying this explosion and hanging on to their flimsy thread of materialism Regards,Ahmad [This message has been edited by Ahmad, 12-01-2002]
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Ahmad Inactive Member |
quote: Then what is "good enough" for you? It seems as though you have pre-decided that no matter what the evidence provided, you will keep on regurgitating that "it ain't good enough". By definition as well by many demonstrated examples, IC is a theory that is still open for more research. Exactly what kind of evidence you're looking for is bizarre to me. I gave you positive evidence for the non-evolvability of IC. I even showed you examples. IC is evident as I many times said before. IC describes a system whose function is dependent on the interaction of multiple components, such that the removal of even one component results in the complete loss of function. Consider the following equation: A + B + C + D ~~~> F where A,B,C, and D represent specific components (gene products) and F represents the function that is elicited by the interaction of these four parts. From this observation, it is evident that F could not possibly evolve by the darwinian evolution, as F requires the presence of all four components. In other words, there would be no selective advantage of having parts A, B, and D compared to an organism having only parts A and B. Why? Because both combinations fail to elicit the function!! So you tell me: HOW CAN SUCH A SYSTEM EVOLVE, in the first place??
quote: Firstly, polyphyletic origins is still a theory, IMO. Secondly, I think polyphyly implies at almost all levels. Thirdly, as I said before, polyphyly implies that the genetic code had multiple independent origins, and is not the result of common ancestry. In light of that, species of mammals always remained as mammals. Reptiles always remained as reptiles. Birds always remained as birds. Now if you want to discuss their origins, that would be an entirely different subject.
quote: ToE predicts "gradual" progressive evolution from simple to complex. This is where it contradicts evolution. Not only there. Now are you denying that "limit" does not exist? Ofcourse, you may postulate alternative theories like modern synthesis or punctuated equilibria part of the noe-darwinism movement. If you do postulate them, I suggest you explain exactly how the alternative theories sufficiently explain the cambrian explosion. Regards,Ahmad
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Ahmad Inactive Member |
Now now brother Andya, don't jump to conclusions. If bony fish, amphibians, dinosaurs, australopiths, humans descended from a single vertebrate ancestor, then that represents the blurry darwinian monophyletic tree. How is that polyphyly? Polyphyly is an important tenet of creation theory. In the case of cambrian explosion at least, creation theory appears to provide the explanation that is most in accordance with the evidence from nature.
Regards,Ahmad
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Ahmad Inactive Member |
quote: I gave you the data with examples.
quote: The eamples I have provided previously serve as the evidence of the non-evolvablility of such systems. If you can show how they evolve, then fine and dandy with me. You're on denial no matter how many evidence is given..
quote: I gave you the evidence, that I consider as positive. It seems as though you're unwilling to accept it.
quote: Now is an argument from defintion, an unbacked assertion or an argument from incredulity? I even gave you examples of systems where all required componenets are needed for the system to function. They can't evolve thus since all their componenets need to be present from the very moment of their existence.
quote: Then where are the transitions??
quote: How is it in "order"? It surely doesn't fit the traditional evolutionary explanation. Nor is it sufficiently explained by the modern neo-darwinian theories, now is it? Now if evolution predicts both increase and decrease in complexity, which one do you think is more plausible? How is the specified complexity increased. Your explanation gives rise to more question than answers.. I guess.
quote: How are transitionals and intermediates found with the present situation of the fossil record? And you're wrong. A progressive simple to complex trend is not seen in the fossil record. In fact the greatest morphological differences appear in the lower Phanerozoic rocks, while the rest of the fossil record consists largely of variations of familiar themes. Regards,Ahmad
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Ahmad Inactive Member |
quote: Sure.. No problem.
quote: Alright.. then get back to my original contention. If evolution does not predict what I stated.. what exactly does it predict then? Lame question to ask but seems vital for our discussion. Now as I know.. it is the general increase in complexity. Is it not? But then how did the wide mosaic of living organisms that just "abruptly" appeared with no evolutionary history or no transitional links, take place? Whats more is that the organisms had novel body plans and highly complex anatomical design. The trilobite eye is just one of the examples. This occurence is very unlikely and contrary to the predictions of evolution. How does evolution explain it?
quote: Well first appearances for orders peak in the Cambrian and Ordovician, but are more broadly distributed. In contrast, first appearances of families, genera and species are relatively low in the Cambrian, and generally increase through the geologic column but they did exist in the cambrian. Now regarding the question of the number of creation events, its still not clear. We really don't know how many creation events took place but we do know the organisms were created. Two evidence is cited for this: 1. Abrupt appearance of almost all phylas, save bryozoans, in a geologically short period of time (~5-10 mya). 2. Organisms differing highly from one another (at the species level) in design and body plans but were indeed complex.
quote: I understood your question now . The answer is: I don't know. Of course, we can all make good predictions. But I have to think over this before I can issue my response. Its a very good question and Insha Allah I will respond to it once I have additional information. Regards,Ahmad
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Ahmad Inactive Member |
quote: Possibly...
quote: You don't seem to understand what I want to say. Consider this simple graph obtained from On the Origin of Stasis According to evolutionary theory, animals had ancestors from which they evolved. Is this explosion of life consistent with an evolutionist interpretation? If these animals, which include some very modern (complex) shelled creatures, sponges, and jawless fish, trilobites did have primitive evolutionary ancestors, where are they to be found in the fossil record? The answer is they aren’t anywhere to be found. Before the Cambrian Period, very few fossil having anything to do with modern phyla are found in the fossil record.
quote: What is the basis for saying there is "an overall trend of increasing complexity"? Now let me choose a group of animal and look attrends in the record. My favuorite example are the trilobites. I've drawn the following mainly from: Babin, C. 1980, "Elements of Palaeontology", John Wiley & Sons Ltd, Chichester. Numerous species of trilobites are found in Lower Cambrian rocks.They are well differentiated from other arthropods, resulting in problems for those who wish to trace an evolutionary ancestry. Babin says their ancestry is "obscure" (p.255). There are about 1500 genera of trilobites known, with a more orless consistent decline in number of genera from the Upper Cambrian to the Permian. From the Upper Ordovician, the number of genera was always less than that in the Lower Cambrian. Thus, there is no trend of increasing numbers of genera in the fossil record. Evolutionary trends have been analysesd as follows: (a) Paedomorphosis (where juvenile features become dominant inthe ontogenesis of descendants). (b) Gerontomorphosis (where adult features become dominant in the ontogenesis of descendants). Sometimes, these two trends coexist: for example, the paedomorphic tendency towards a reduction in the number of thoracic segments has been observed to coexist with the gerontomorphic tendency towards the enlargement of the rachis. Overall, there are no dominant trends and Babin writes that the data "still tends to be difficult to interpret" (p.262). Whatever these trends are, can they be interpreted in any way asan increase in complexity? Neither of the reported trends involves novel structures - only modifications of existing structures. Trilobite morphologies are, of course, very diverse. Cambrianfaunas are distinctive, although some of these forms are also found in Ordovician strata. A number of variants are found in the base of the Ordovician, but these are localised stratigraphically. The dominant Ordovician groups have a much broader range. Above the Ordovician, according to Nield and Tucker (1985), "there seems to have been little further development in the overall design of trilobites, with only minor variations on the basic themes stated in the early Ordovician" (p.26). The conclusion: in the context of trilobites, claims of increasingcomplexity in the fossil record appear to lack a solid foundation. quote: I don't want to think what evolution says but want to hear it from the horse's mouth. What exactly does evolution predict? Its very relevant and certainly not a strawman.
quote: Just like to respond to your previous question: "At what classification level was life made polyphyletic?" It's quite hard to be specific in this case. Especially when you're dealing with taxonomy. Since polyphyly implies that the genetic code had multiple independent origins, ascribing it to one classification level can hardly be in general. I'll add some more thoughts to this next time Insha Allah. Regards,Ahmad
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Ahmad Inactive Member |
Mark,
quote: I should remind you that fossils of soft-bodied organisms are famously found in Cambrian Preservat-Lagerstatten such as the Burgess Shale and the Chengjiang locality in China. Fossil bacteria are reported from both Precambrian and Phanerozoic rocks. Why would depositional conditions favor preservation of bacteria in both Precambrian and Phanerozoic rocks, but soft-bodied multicellular organisms only in the Phanerozoic and uppermost Precambrian? The fossil record is obviously incomplete, but there is no evidence it is so incomplete it would not preserve fossils of soft-bodied organisms for half their supposed geologic history!!
quote: I haven't the slightest idea. Species appear and disappear abruptly, according to scientists and they show no "gradual evolution" but "the sudden explosion of one group at the expense of another". Thats the sole problem of evolution. Where, indeed, are the missing fossils... the missing links?
quote: You have generalized it greatly. Only if you go into details of the trend, you might realize how incredibly random it is (like I have described in the case of the trilobites).
quote: Interesting but would you consider the remarkable similarities between bacteria billions of years old and present bacteria? Have they not undergone evolution of any sort? Regards,Ahmad
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