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Two Concepts of Evolution

  1. Mar 20, 2004 #1
    Until the mid-1980s, the understanding of the development of animal life was that it had followed the logical path of a gradual evolution with more simple phyla over eons leading into more complex phyla.

    With the rediscovery of fossils held quietly in the dusty drawers of the Smithsonian Institution since 1909, this concept underwent a drastic revision. These fossils in conjunction with other discoveries indicate that all animal phyla appeared almost simultaneously 530 million years ago in the Cambrian period.

    All further development was confined to variations within each phylum. One of the great mysteries of animal evolution is WHY no new phyla have evolved or appeared since that Cambrian explosion of life as now documented by all fossil evidence in the world libraries and museums?

    What happened to any NEW PHYLA EVOLUTION since that Cambrian period some half billion years ago? How long are we to wait for some new phyla to evolve?
     
    Last edited: Mar 20, 2004
  2. jcsd
  3. Mar 20, 2004 #2
    There's no great mystery...where would a new phylum go?
     
  4. Mar 20, 2004 #3
    Originally posted by Zero

    There's no great mystery...where would a new phylum go?

    Right into the proof column of the theory of evolution.
     
  5. Mar 20, 2004 #4
    Ummm, no, I meant physically, where would you put an entire new phylum of creatures, geographically?
     
  6. Mar 20, 2004 #5

    selfAdjoint

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    My theory is that the Burgess shale explosion of phyla coincided with the evolution of the "homeobox" genes. These enabled a complex body plan to be developed. And all the niches available to various combinations of homeo genes were quickly explored. Many turned out to be not viable in the long run and the rest lived on to give us our modern phyla. Any new body plan that might arise by mutation would have to compete with established phyla already on the scene. So the laws of probability would say that it's extremely unlikely that a new body plan would be anything but a relative failure.
     
  7. Mar 20, 2004 #6
    Originally posted by Zero

    Ummm, no, I meant physically, where would you put an entire new phylum of creatures, geographically?

    If the phylum had lungs and limbs, it would appear on the land and if gills and scales, in the sea.

    Your meaning is unclear to me as any brand new phyla appearing anywhere on planet earth would create a world-wide riot in the scientific community similar to the report in the New York Times on April 23, 1991 titled "Spectacular Fossils Record Early Riot of Creation" referencing the dramatic conclusion that a burst of multicellular life was found during the Cambrian era, more than one-half billion years ago.

    Not one new phyla found since that Cambrian Era.
     
  8. Mar 20, 2004 #7
    Originally posted by selfAdjoint

    My theory is that the Burgess shale explosion of phyla coincided with the evolution of the "homeobox" genes. These enabled a complex body plan to be developed. And all the niches available to various combinations of homeo genes were quickly explored. Many turned out to be not viable in the long run and the rest lived on to give us our modern phyla. Any new body plan that might arise by mutation would have to compete with established phyla already on the scene. So the laws of probability would say that it's extremely unlikely that a new body plan would be anything but a relative failure.

    I like your theory about the Burgess shale explosion of phyla coinciding with the mysterious presence of 'homeobox' genes.

    Some evolutionists hailed homeobox or hox genes as the saviour of evolution soon after they were discovered. They seemed to fit into the Gouldian mode of evolution (punctuated equilibrium) because a small mutation in a hox gene could have profound effects on an organism. However, further research has not born out many people's evolutionists’ hopes. Dr Christian Schwabe, the non-creationist sceptic of Darwinian evolution from the Medical University of South Carolina (Dept. of Biochemistry and Molecular Biology), wrote:

    His book scientifically fights your theory on the factual terms, on their issues, using their testimony, and their ground rules. This non-cretionist dismantles many evolutionary illusions, and offers a new creation theory of biology.

    He says that ‘Control genes like homeotic genes may be the target of mutations that would conceivably change phenotypes, but one must remember that, the more central one makes changes in a complex system, the more severe the peripheral consequences become. Homeotic changes induced in Drosophila genes have led only to monstrosities, and most experimenters do not expect to see a bee arise from their Drosophila constructs.’

    Research in the six years since Schwabe wrote this has only born out his statement. Changes to homeotic genes cause monstrosities (two heads, a leg where an eye should be, etc.); they do not change an amphibian into a reptile, for example. And the mutations do not add any information, they just cause existing information to be mis-directed to produce a fruit-fly leg on the fruit-fly head instead of on the correct body segment.

    Of course, you are using the ubiquity of hox genes in your argument for common ancestry (‘Look, all these creatures share these genes, so all creatures must have had a common ancestor’). However, commonality of such features is to be expected with their origin from the same source. All such homology arguments are only arguments for evolution when one excludes, a priori, origins by design. Indeed many of the patterns seen do not fit common ancestry. For example, the discontinuity of distribution of hemoglobin-like proteins, which are found in a few bacteria, molluscs, insects, and vertebrates. One could also note features such as vivipary, thermoregulation (some fish and mammals), eye designs, etc.

    You will simply have to give more proof of your theory of homeobox genes sudden appearance as the origin of early DNA pattern for phyla.
     
    Last edited: Mar 20, 2004
  9. Mar 20, 2004 #8
    You might want to watch your quotations from other sources...make sure it is clear what you are quoting, and what your own ideas are.


    BTW, are YOU a creationist, ID proponent, or otherwise deficient in the understanding of science? (I'm kidding)
     
  10. Mar 20, 2004 #9

    FZ+

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    I don't think you understand what phyla are. It may be noted that practically all macroscopic animal life, from fish to us are listed under one single phyla - the chordates. Phyla represent a collossal difference, something fundamental that gets added on during relative simplicity and much more other stuff are built on top of. The current state of things are too full of competition, and so on, for there to be a niche for a new phyla to appear.

    A list of phyla:

    http://www.abdn.ac.uk/~nhi708/classify/animalia/
     
  11. Mar 20, 2004 #10
    Oops, I forgot to get back to that...that was my point exactly. Nearly every life-sustaining niche has been filled by some form of life. Where there is little life, evolutionary forces will shape existing species to fill each niche. But, once the niche is filled, it becomes nearly impossible for another species to compete with it. How then would we expect an entirely new phylum to come into existance, when it is hard enough for a new species to get a foothold?
     
  12. Mar 20, 2004 #11
  13. Mar 20, 2004 #12

    selfAdjoint

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    He says that ‘Control genes like homeotic genes may be the target of mutations that would conceivably change phenotypes, but one must remember that, the more central one makes changes in a complex system, the more severe the peripheral consequences become. Homeotic changes induced in Drosophila genes have led only to monstrosities, and most experimenters do not expect to see a bee arise from their Drosophila constructs.’

    Well that doesn't contradict my theory since I did point out that after the first radiation, the mutation of the hox genes would be very unlikely to produce a valid competitor phylum. For example I would expect mutations in the hox genes of vertibrates to produce nonviable fetuses.
     
  14. Mar 20, 2004 #13
    Originally posted by FZ+

    I don't think you understand what phyla are. It may be noted that practically all macroscopic animal life, from fish to us are listed under one single phyla - the chordates. Phyla represent a collossal difference, something fundamental that gets added on during relative simplicity and much more other stuff are built on top of. The current state of things are too full of competition, and so on, for there to be a niche for a new phyla to appear. A list of phyla:
    http://www.abdn.ac.uk/~nhi708/classify/animalia/


    FZ+ as I understand it phyla are morphologically based branches of the tree of life on planet earth.

    The different three morphological phyla types on earth being Bacteria, Archaea and Eukarya.

    The following graph demonstrates darwinian theory vs. the fossil record to this point in time. And you are correct in my confusion and error with phyla progression changes in the tree classifications of specie and class.

    http://id-www.ucsb.edu/fscf/library/origins/CATALOG/FIGJ.html

    The next graph demonstrates the "vast majority of phyla appear abruptly with low species diversity. The disparity of the higher taxa precedes the diversity of the lower taxa."

    http://id-www.ucsb.edu/fscf/library/origins/CATALOG/FIGH.html

    The last graph demonstrates evidence of sudden appearnce and stasis.

    http://id-www.ucsb.edu/fscf/library/origins/CATALOG/FIGI.html

    Darwin wrote, (*note Darwin's referral to the Silurian period is now known as the Cambrian era)

     
  15. Mar 20, 2004 #14
    Ummm...talus, you do realize that when Darwin said "at present", it was 1859?:wink:
     
  16. Mar 20, 2004 #15
    Originally posted by Zero
    Ummm...talus, you do realize that when Darwin said "at present", it was 1859?

    I enjoyed your critical site of biochemist Schwabe but the article actually admits that both Darwin and Schwabe are both the extremes and that there must be a central ground. The following quote from your article appears to make Schwabe's one-time lucky event and the chance-oriented Darwin construct appear to be one and the same.

    Yes Darwin did say 'at present' in the admission of his possible error statment in the year 1859. What has bascially changed since that 1859 time which alters Darwin's basic evolutionary premise in 2004's scientific community?
     
  17. Mar 20, 2004 #16
    Originally posted by selfAdjoint

    He says that ‘Control genes like homeotic genes may be the target of mutations that would conceivably change phenotypes, but one must remember that, the more central one makes changes in a complex system, the more severe the peripheral consequences become. Homeotic changes induced in Drosophila genes have led only to monstrosities, and most experimenters do not expect to see a bee arise from their Drosophila constructs.’

    Well that doesn't contradict my theory since I did point out that after the first radiation, the mutation of the hox genes would be very unlikely to produce a valid competitor phylum. For example I would expect mutations in the hox genes of vertibrates to produce nonviable fetuses.

    Are you saying that the first radiation of various combinations of homeotic genes were "quickly" explored for an initially complex aberrant construct which was somehow successful. Then "quickly" disappeared because any further use of this gene would result in mutations producing nonviable fetuses? Or that everything originated from one phylum as contradicted by the fossil record as shown in previous thread graphs.

    What are the chances of such a one time event occurring once in even 2X the full span of time speculated for the beginning of the universe until now?
     
    Last edited: Mar 20, 2004
  18. Mar 20, 2004 #17
    *rolls eyes*

    Do you think anyone today is a strict Darwinist? Old Charles would hardly recognise today's evolutionary science, so attacking Darwin is attacking a strawman.
     
  19. Mar 20, 2004 #18
    Originally posted by Zero

    *rolls eyes*

    Do you think anyone today is a strict Darwinist? Old Charles would hardly recognise today's evolutionary science, so attacking Darwin is attacking a strawman.


    *amazement*

    Before I can avoid that Darwin 'strawman' again I need to understand your personal construct of 'currently recognized', 'accepted', 'fixed' evolutionary science as apposed to various evolution theorists, biologists and scientists with differing perspectives of Darwin's 1859 original theory.
     
  20. Mar 20, 2004 #19

    FZ+

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    You must additionally recognise that the so-called cambrian explosion may be only due to the start of fossilisation - pre-cambrian types may well have existed, but were undetectable because they did not secrete minerals etc to leave a genuine trace.

    For a start, we actually have a theory of genetics, by which we observe that morphology is often hugely misleading - leaves etc are in fact very easy to produce, by the repitition of small parts, and that's why they are common in nature. We also understand a much greater changebility in the rate of evolution, involve in our models more of the inherent feedback between the organism and its environment, involve theories of co-evolution to see how ecosystems appear, view evolution in terms of new mathematical techniques of dynamical systems, and so on and so forth.
     
  21. Mar 20, 2004 #20

    Nereid

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    IMHO there's an awful lot of stuff here mixed up, resulting in much confusion.

    1) The taxonomic hierarchy is:
    Kingdom
    Phylum (Division for plants)
    Class
    Order
    Family
    Genus
    Species

    2) Little is known about the evolution of multi-cellular organisms before the Cambrian, for the good reason that there is little in the fossil record on which to base assignment of taxa (there's plenty of evidence of eukaryotes, just not enough to be able to classify them into classes etc)

    3) The vertiginous mixing of Darwin's words with echoes of modern evolution theory - Darwin got it wrong, in many respects (he was a scientist, science progresses), Gould is just one of those who've developed the theory of evolution since Darwin
     
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