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  1. #1 Tuatara 
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    Evolving or not?

    The tuatara has remained virtually unchanged over the past 140 million years.
    Link

    "What we found is that the tuatara has the highest molecular evolutionary rate that anyone has measured," Professor Lambert says.
    Link

    So let me get this straight, the fastest evolving animal known to man hasn't changed in the last 140 million years?


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    a change in genotype doesn't always have to be reflected in a similar-size change in phenotype, and vice versa


    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
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    The tuatara has remained morphologically unchanged, and the morphology in question would be bone morphology only, since soft tissues from 140 million years ago don't fossilize. They could have changed extensively in any variety of soft tissues or other systems like the immune system, or even behavioral suites.
    Man can will nothing unless he has first understood that he must count on no one but himself; that he is alone, abandoned on earth in the midst of his infinite responsibilities, without help, with no other aim than the one he sets himself, with no other destiny than the one he forges for himself on this earth.
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    If it's the fastest evolving animal, why is it's phenotype unchanged?
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    more often than not alterations to the genotype are likely to remain in place when the changes happen in the portion of the DNA that does not get expressed

    changes in the genotype that does get expressed is subject to natural selection and may be culled if in some way disadvantageous

    does anyone know whether the tuatara has an exceptionally large portion of "junk" DNA ?
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    Didn't you read what I wrote?

    Phenotype is the WHOLE animal - soft tissue, immune system, behavior, etc etc. The ONLY portion of phenotype that we are we are SURE is unchanged from 140 million years ago is the BONES, because those are the only things that fossilize.

    Just because the bones look similar doesn't mean changes in other areas hasn't happened.
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    Quote Originally Posted by paralith
    Didn't you read what I wrote?

    Phenotype is the WHOLE animal - soft tissue, immune system, behavior, etc etc. The ONLY portion of phenotype that we are we are SURE is unchanged from 140 million years ago is the BONES, because those are the only things that fossilize.

    Just because the bones look similar doesn't mean changes in other areas hasn't happened.
    So the only reason why scientists say it's unchanged in 140 million years is because it's bones are the same?

    Why are it's bones the same? If it's the fastest evolving animal shouldn't it's bones have evolved?

    And what animals have evolved from the Tuatara?
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    To evolve is to change. It is not required that the tuatara budded off several new species before we can say it evolved.

    There are no requirements for what changes and how it changes in evolution. If the bone structure was ideal for the environment, then it won't change. If what kept changing was, say, viruses and other pathogens, and the tuataras had to keep evolving their immune systems in order to survive, a great deal of genetic change could accrue in genes related to immunity.
    Man can will nothing unless he has first understood that he must count on no one but himself; that he is alone, abandoned on earth in the midst of his infinite responsibilities, without help, with no other aim than the one he sets himself, with no other destiny than the one he forges for himself on this earth.
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    Quote Originally Posted by paralith
    To evolve is to change.
    So some animals don't evolve since they haven't changed. E.g. cyanobacteria, echinoids, sharks, tuatara, etc.

    It is not required that the tuatara budded off several new species before we can say it evolved.
    What did the Tuatara evolve into?

    There are no requirements for what changes and how it changes in evolution.
    So "evolution" can mean anything basically?

    If the bone structure was ideal for the environment, then it won't change.
    So prokaryotes, echinoids, sharks, etc don't evolve.

    If what kept changing was, say, viruses and other pathogens, and the tuataras had to keep evolving their immune systems in order to survive, a great deal of genetic change could accrue in genes related to immunity.
    But you would have no way of knowing that since the only evidence we have are unchanged bones.
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    Quote Originally Posted by Total Science
    If it's the fastest evolving animal, why is it's phenotype unchanged?
    Gross morphology is not the only measure of phenotype.
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  12. #11  
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    Quote Originally Posted by Total Science
    Quote Originally Posted by paralith
    To evolve is to change.
    So some animals don't evolve since they haven't changed. E.g. cyanobacteria, echinoids, sharks, tuatara, etc.
    All of these have changed in some manner over time. Further, the "animals" you have listed (with the exception of the tuatara) are not species but entire families of species with great variety within them

    Quote Originally Posted by Total Science
    It is not required that the tuatara budded off several new species before we can say it evolved.
    What did the Tuatara evolve into?
    [/quote]

    A tuatara with some minor differences? It is quite possible for a species to evolve and remain the same species. If this were not possible, evolution wouldn't work at all in multicellular organisms.

    Quote Originally Posted by Total Science
    There are no requirements for what changes and how it changes in evolution.
    So "evolution" can mean anything basically?
    Where'd you get that idea? If you're not sure what evolution is, we can explain it to you in full or direct you to a decent source.


    Quote Originally Posted by Total Science
    If the bone structure was ideal for the environment, then it won't change.
    So prokaryotes, echinoids, sharks, etc don't evolve.
    Organisms always evolve, but they undergo changes at different rates. Many shark species are evolving at a rate considerably lower than average as the selective pressures upon them, the drives to evolve, are relatively weak.

    Quote Originally Posted by Total Science
    If what kept changing was, say, viruses and other pathogens, and the tuataras had to keep evolving their immune systems in order to survive, a great deal of genetic change could accrue in genes related to immunity.
    But you would have no way of knowing that since the only evidence we have are unchanged bones.
    [/quote]

    There's evidence aside from the bones. Read the second link you provided. They isolated DNA from 8000 year old bones and newer and based their new assessment of the rate of evolution upon that. The changes to the genome that were not reflected in gross morphology, though that's not very surprising given the timescale.
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    Quote Originally Posted by TheBiologista
    Quote Originally Posted by Total Science
    If it's the fastest evolving animal, why is it's phenotype unchanged?
    Gross morphology is not the only measure of phenotype.
    That does not address the question. Why hasn't the morphology evolved?
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    Quote Originally Posted by TheBiologista
    All of these have changed in some manner over time.
    If evolution is defined as "change in some manner over time" then even creationists believe in evolution.

    There's evidence aside from the bones. Read the second link you provided.
    I knew paralith had to be wrong abnout that. Thank you for correcting him.
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  15. #14  
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    TS, you're trolling.

    We don't deserve this. You don't deserve this. You're an intelligent guy and can do better.
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  16. #15  
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    Quote Originally Posted by Total Science
    Quote Originally Posted by TheBiologista
    Quote Originally Posted by Total Science
    If it's the fastest evolving animal, why is it's phenotype unchanged?
    Gross morphology is not the only measure of phenotype.
    That does not address the question. Why hasn't the morphology evolved?
    Paralith already explained that to you. Presumably because there was no selective pressure in favour of change but rather one which favoured a stable morphology. This tends to happen when an organism enters a niche/environment which has stable aspects. This does not mean that all traits become stable (unless every conceivable selective pressure remained constant), but those selected for by the stable environmental elements will.

    Quote Originally Posted by Total Science
    Quote Originally Posted by TheBiologista
    All of these have changed in some manner over time.
    If evolution is defined as "change in some manner over time" then even creationists believe in evolution.
    The creationists tend to talk about "microevolution" as being possible. That is to say, evolution within the "created kinds", and generating no new functional "information". They don't rigorously define what kinds or information are, so on those counts they don't have a scientific argument. They also tend to consider the world to be less than 10,000 years old, so evolution would not have the time to proceed even to the extent they claim unless the theory is incorrect.

    Quote Originally Posted by Total Science
    There's evidence aside from the bones. Read the second link you provided.
    I knew paralith had to be wrong abnout that. Thank you for correcting him.
    Paralith told you that morphology was not the only means by which evolution could be measured. That is correct. She also alluded to other traits that might have undergone evolution that would not be detectable by mere examination of bones from 140 million years ago. Also correct. She also explained how the morphology could undergo minimal changes whilst other traits underwent significant evolution. Correct yet again. Where is she wrong exactly?

    The first contention (that the Tuatara was evolving very slowly) was based on bone morphology from 140 million years ago to the present, whereas the second contention (that said species was actually evolving very quickly) was based on DNA from bone samples only 8000 years old and younger. So whilst it is correct to say that the Tuatara evolved slowly in terms of gross morphology, more recent data suggests that other traits were evolving very quickly indeed.

    Clear enough?
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    Quote Originally Posted by TheBiologista
    Presumably because there was no selective pressure in favour of change but rather one which favoured a stable morphology.
    Why was there no selective pressure? I thought natural selection is the driving force of evolution.

    This tends to happen when an organism enters a niche/environment which has stable aspects.
    The Earth is a niche environment with stable aspects.

    Quote Originally Posted by Total Science
    Quote Originally Posted by TheBiologista
    All of these have changed in some manner over time.
    If evolution is defined as "change in some manner over time" then even creationists believe in evolution.
    The creationists tend to talk about "microevolution" as being possible. That is to say, evolution within the "created kinds", and generating no new functional "information".
    So what's the problem then? Why can't atheists coexist peacefully with them?

    They don't rigorously define what kinds or information are, so on those counts they don't have a scientific argument.
    DNA isn't defined?

    They also tend to consider the world to be less than 10,000 years old, so evolution would not have the time to proceed even to the extent they claim unless the theory is incorrect.
    Who are you talking about? I don't know any creationists that think that.

    Quote Originally Posted by Total Science
    There's evidence aside from the bones. Read the second link you provided.
    I knew paralith had to be wrong about that. Thank you for correcting him.
    Paralith told you that morphology was not the only means by which evolution could be measured. That is correct. She also alluded to other traits that might have undergone evolution that would not be detectable by mere examination of bones from 140 million years ago. Also correct. She also explained how the morphology could undergo minimal changes whilst other traits underwent significant evolution. Correct yet again. Where is she wrong exactly?
    You said she's wrong.

    Quote Originally Posted by paralith
    The ONLY portion of phenotype that we are we are SURE is unchanged from 140 million years ago is the BONES, because those are the only things that fossilize.
    The first contention (that the Tuatara was evolving very slowly) was based on bone morphology from 140 million years ago to the present, whereas the second contention (that said species was actually evolving very quickly) was based on DNA from bone samples only 8000 years old and younger. So whilst it is correct to say that the Tuatara evolved slowly in terms of gross morphology, more recent data suggests that other traits were evolving very quickly indeed.

    Clear enough?
    To you maybe.
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    science, Sarah Palin thinks the world is less than 10,000 years old. To be exact, she thinks it is only 6,000.
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    Quote Originally Posted by verzen
    science, Sarah Palin thinks the world is less than 10,000 years old. To be exact, she thinks it is only 6,000.
    Link please.

    For the record, the Roman Catholic Church which is the biggest group of creationists (80 million or 25% of Americans) does not have an official position on the age of the Earth.

    Much less has been defined as to when the universe, life, and man appeared. The Church has infallibly determined that the universe is of finite age—that it has not existed from all eternity—but it has not infallibly defined whether the world was created only a few thousand years ago or whether it was created several billion years ago.

    Catholics should weigh the evidence for the universe’s age by examining biblical and scientific evidence. "Though faith is above reason, there can never be any real discrepancy between faith and reason. Since the same God who reveals mysteries and infuses faith has bestowed the light of reason on the human mind, God cannot deny himself, nor can truth ever contradict truth" (Catechism of the Catholic Church 159).

    The contribution made by the physical sciences to examining these questions is stressed by the Catechism, which states, "The question about the origins of the world and of man has been the object of many scientific studies which have splendidly enriched our knowledge of the age and dimensions of the cosmos, the development of life-forms and the appearance of man. These discoveries invite us to even greater admiration for the greatness of the Creator, prompting us to give him thanks for all his works and for the understanding and wisdom he gives to scholars and researchers" (CCC 283).
    Link
    "The most likely site for error is in the most fundamental of our beliefs." -- Samuel Warren Carey, geologist, 1988
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  20. #19  
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    Quote Originally Posted by Total Science
    Quote Originally Posted by TheBiologista
    Presumably because there was no selective pressure in favour of change but rather one which favoured a stable morphology.
    Why was there no selective pressure? I thought natural selection is the driving force of evolution.
    I did not say there was no selective pressure (that would cause genetic drift, not a static morphology). I said there was no pressure in favour of change. A pressure may act to enforce no change. For example, the mutation of the CFTR gene in humans is not favoured by the environment. So we tend to be selected not to change in that respect. For a set of traits (such as gross morphology) to remain static, it must be disadvantageous for change to occur.

    Also, "selective pressure" is not a single, unified phenomenon. Being hunted by a species is one selective pressure and will act upon certain traits. A change in atmospheric temperature would be another selective pressure that might act upon other traits.

    Quote Originally Posted by Total Science
    This tends to happen when an organism enters a niche/environment which has stable aspects.
    The Earth is a niche environment with stable aspects.
    Yes, and traits relevant to those stable aspects are stable. Most organisms use DNA as genetic material. Most organisms have enzymes which function within the range of temperatures that generally occur on Earth. We can look at environment on several scales and find that these rules hold.

    Quote Originally Posted by Total Science
    Quote Originally Posted by Total Science
    Quote Originally Posted by TheBiologista
    All of these have changed in some manner over time.
    If evolution is defined as "change in some manner over time" then even creationists believe in evolution.
    The creationists tend to talk about "microevolution" as being possible. That is to say, evolution within the "created kinds", and generating no new functional "information".
    So what's the problem then? Why can't atheists coexist peacefully with them?
    Atheists? Scientists are philosophically obliged to attack all assertions that cannot be back up with evidence. Microevolution makes no sense as there is no practical barrier between the processes of evolution over short time scales versus long time scales. To assert otherwise is misleading. Further, to attempt to have such beliefs promoted as science, or even taught to children as such, is misleading.

    Quote Originally Posted by Total Science
    They don't rigorously define what kinds or information are, so on those counts they don't have a scientific argument.
    DNA isn't defined?

    They also tend to consider the world to be less than 10,000 years old, so evolution would not have the time to proceed even to the extent they claim unless the theory is incorrect.
    Who are you talking about? I don't know any creationists that think that.
    Then perhaps you have yet to meet any Young Earth Creationists. I have met several. They typically consider the Earth to be approximately 6000 years old.

    http://en.wikipedia.org/wiki/Young_Earth_creationism

    Quote Originally Posted by Total Science
    Quote Originally Posted by Total Science
    There's evidence aside from the bones. Read the second link you provided.
    I knew paralith had to be wrong about that. Thank you for correcting him.
    Paralith told you that morphology was not the only means by which evolution could be measured. That is correct. She also alluded to other traits that might have undergone evolution that would not be detectable by mere examination of bones from 140 million years ago. Also correct. She also explained how the morphology could undergo minimal changes whilst other traits underwent significant evolution. Correct yet again. Where is she wrong exactly?
    You said she's wrong.

    Quote Originally Posted by paralith
    The ONLY portion of phenotype that we are we are SURE is unchanged from 140 million years ago is the BONES, because those are the only things that fossilize.
    The first contention (that the Tuatara was evolving very slowly) was based on bone morphology from 140 million years ago to the present, whereas the second contention (that said species was actually evolving very quickly) was based on DNA from bone samples only 8000 years old and younger. So whilst it is correct to say that the Tuatara evolved slowly in terms of gross morphology, more recent data suggests that other traits were evolving very quickly indeed.

    Clear enough?
    To you maybe.
    I don't know how to explain it better. Essentially the first contention is inaccurate, but could be said to be correct with a whole lot of caveats. The second is based on more evidence on a different time scale. Paralith and I are on the same page on that.
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    And you've done it again, Totalscience. You've taken what should have ended up as an interesting titbit on Tuataras and instead turned it into an exhibition of stubborn ignorance.

    Your definition of evolution is simplistic in the extreme. It is well known that two different animals can have very similar body plans when they exist in similar habitats, have similar diets, etc. It’s known as convergent evolution (and similarly parallel evolution and evolutionary relay) and it explains rather neatly similar traits shared between different lineages.

    So if an animal had pretty much the perfect body plan for its environment and habits, why would it change? Remember, evolution is blind and it does not necessarily mean that an animal has to change into something else (superficially) over time. If the environment changes beyond a certain point and no beneficial mutations happen in time (or it can find a reasonably similar environment close by), it dies out. The Tuatara, evidently, was never put in a position where its bone structure was not suitable for any changes that might have come across its path, but, as has been pointed out, this does not mean that nothing has changed. This is the clear picture that your two links paint.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    Quote Originally Posted by TheBiologista
    I said there was no pressure in favour of change.
    But I thought pressure is the driving force of evolution.

    Quote Originally Posted by Thebiologista
    A pressure may act to enforce no change.
    In other words, some animals don't evolve.

    Quote Originally Posted by TheBiologista
    Scientists are philosophically obliged to attack all assertions that cannot be back up with evidence.
    Exactly why I attack plate tectonics and other religious dogma.

    Quote Originally Posted by TheBiologista
    Then perhaps you have yet to meet any Young Earth Creationists. I have met several. They typically consider the Earth to be approximately 6000 years old.

    http://en.wikipedia.org/wiki/Young_Earth_creationism
    Are they related to Young Earth Atheists?

    http://www.youtube.com/watch?v=h1lBxrUFbZ8

    Quote Originally Posted by KALSTER
    Your definition of evolution is simplistic in the extreme.
    You don't know what my definition of evolution is. Unless you've evolved atheist demigod ESP powers.

    Remember, evolution is blind and it does not necessarily mean that an animal has to change into something else (superficially) over time.
    So what does it mean then?
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    Quote Originally Posted by Total Science
    Quote Originally Posted by TheBiologista
    I said there was no pressure in favour of change.
    But I thought pressure is the driving force of evolution.
    It is one of the main influences on evolution, yes. But it can both drive change and drive stability. And I stress that this is on a trait-by-trait basis. Morphology may be selected to remain constant for a time whilst some biochemical pathways change rapidly at the same time. It's evolution in both cases.

    Quote Originally Posted by Total Science
    Quote Originally Posted by Thebiologista
    A pressure may act to enforce no change.
    In other words, some animals don't evolve.
    Not exactly. Some traits in some species may remain unchanged for a considerable time. This does not mean they are not evolving. To my knowledge, we've never observed a species that was not undergoing changes to some trait or other, even if many of its traits were static.

    Quote Originally Posted by Total Science
    Quote Originally Posted by TheBiologista
    Scientists are philosophically obliged to attack all assertions that cannot be back up with evidence.
    Exactly why I attack plate tectonics and other religious dogma.
    Good luck with that. Plate tectonics is a well-accepted theory for good reason. There's massive amounts of evidence in support of it. But if you find yourself with little to do I guess it'll keep you busy.

    Quote Originally Posted by Total Science
    Quote Originally Posted by TheBiologista
    Then perhaps you have yet to meet any Young Earth Creationists. I have met several. They typically consider the Earth to be approximately 6000 years old.

    http://en.wikipedia.org/wiki/Young_Earth_creationism
    Are they related to Young Earth Atheists?

    http://www.youtube.com/watch?v=h1lBxrUFbZ8
    I doubt there's any relation as the man in your video is being very heavy-handedly satirical, whilst most young Earth creationist are, sadly, quite serious about the age of the Earth. Are you, by any chance, also a young Earth atheist?
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    Quote Originally Posted by TheBiologista
    Plate tectonics is a well-accepted theory for good reason. There's massive amounts of evidence in support of it.
    That's exactly what the Young Earth Creationists say.
    "The most likely site for error is in the most fundamental of our beliefs." -- Samuel Warren Carey, geologist, 1988
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    So what does it mean then?
    Did you notice the part in brackets, i.e. superficially? To a casual eye the organism could look (the bones) pretty much the same, but closer analysis (DNA) can reveal major changes, again, as your two links show.

    You don't know what my definition of evolution is.
    Have we not been discussing it? Do I need ESP to read? Why don’t you tell us your definition then?
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    Quote Originally Posted by Total Science
    Quote Originally Posted by TheBiologista
    Plate tectonics is a well-accepted theory for good reason. There's massive amounts of evidence in support of it.
    That's exactly what the Young Earth Creationists say.
    No they don't, the YEC crowd are all about Flood geology. The only time they bring in tectonics is when they talk about runaway subduction in some effort to explain where all the water from Noah's Flood went to. Standard plate tectonics don't make them happy as it suggests the world is too old.
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    The answer to the question is simple. The original statement was wrong.

    Not sure where you got it from, but the Tuatara has changed substantially. What has not changed is that it is still a member, and the last surviving member of the reptilian order Rhynchocephalia. It retains all the features of rhynchocephalians, which is an order that goes back to the dinosaurs. In the sense that it retains rhynchocephalian features, it has not changed.

    However, the tutatara as a species is NOT unchanged for all those millions of years. It is a recent species, just as all other reptilian species are recent. To say it is unchanged makes as much sense as to say a lizard is unchanged for 50 million years, since its ancestor 50 million years ago was a lizard, even though the ancestor would have been a totally different species.

    In fact, it is probably not even an old resident of New Zealand. There is increasing evidence that the whole country went underwater in the Miocene, and all life forms were wiped out. The ancestor of the tuatara arrived after that time, and evolved to adapt to its new environment.
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