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Member (Idle past 4489 days) Posts: 250 From: Tasmania, Australia Joined: |
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Author | Topic: Adding information to the genome. | ||||||||||||||||||||||||||||||||||||||||||||
Coyote Member (Idle past 2106 days) Posts: 6117 Joined:
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The new field of genetics could have caused a major revision Motoo Kimura stated that his Neutral Theory showed the "great majority" of evolution at the molecular level was caused by genetic drift and not natural selection. You don't regard this as a major revision? Kimura studied proteins and genes, and showed that they exhibited little evidence of natural selection, whereas studies of whole organisms showed a great deal of natural selection. Not hardly the same thing at all! And evolution works with whole populations. No, genetics did not overturn previous theory, nor did Kimura.
Perhaps creationists should not try to dabble in science, eh? Being against science and the scientific method because of their religious beliefs, they tend not to learn enough about it to make meaningful comments. Which ones in particular? Isaac Newton? John Sanford? Simon Conway Morris? Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
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cavediver Member (Idle past 3644 days) Posts: 4129 From: UK Joined: |
Motoo Kimura stated that his Neutral Theory showed the "great majority" of evolution at the molecular level... You know, you've repeated this a thousand times, and you still haven't noticed those magic words "at the molecular level". They do actually mean something even if the nuance is lost on you...
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Kaichos Man Member (Idle past 4489 days) Posts: 250 From: Tasmania, Australia Joined: |
Kimura studied proteins and genes, and showed that they exhibited little evidence of natural selection, whereas studies of whole organisms showed a great deal of natural selection. Not hardly the same thing at all! And evolution works with whole populations. So the genotype evolves by one method, the phenotype by another?
Those folks who were creationists and who made names for themselves in science did so by following the scientific method But didn't you just write:
Being against science and the scientific method because of their religious beliefs, they tend not to learn enough about it to make meaningful comments. Were you wrong then? Or now? "Often a cold shudder has run through me, and I have asked myself whether I may have not devoted myself to a fantasy." Charles Darwin
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Kaichos Man Member (Idle past 4489 days) Posts: 250 From: Tasmania, Australia Joined: |
"at the molecular level" So I'll put to you the same question I've just put to Coyote: do you believe the genotype evolves by one method, the phenotype by another? "Often a cold shudder has run through me, and I have asked myself whether I may have not devoted myself to a fantasy." Charles Darwin
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Percy Member Posts: 22394 From: New Hampshire Joined: Member Rating: 5.2
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Kaichos Man writes: Motoo Kimura stated that his Neutral Theory showed the "great majority" of evolution at the molecular level was caused by genetic drift and not natural selection. You don't regard this as a major revision? Whether you define evolution as Darwin did (descent with modification and natural selection) or in a more modern way (change in allele frequency over time), Kimura's neutral theory had no impact on either. His work addressed some underlying genetic mechanisms behind one type of evolutionary change, not the basic structure of evolutionary theory. --Percy
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Percy Member Posts: 22394 From: New Hampshire Joined: Member Rating: 5.2
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Kaichos Man writes: So I'll put to you the same question I've just put to Coyote: do you believe the genotype evolves by one method, the phenotype by another? Cavediver was just pointing out that you've been ignoring the "at the molecular level" portion of your Kimura quote. Kimura showed that most mutations cause little or no phenotypic change. Obviously that means that the rest of the mutations do cause phenotypic change. It comes up in discussions here over and over again that most mutations don't have much if any detectable effect, and Kimura's research is one way we've come to understand this. But you seem to be misinterpreting his research as showing that mutations cannot cause any phenotypic change. --Percy Edited by Percy, : Typo.
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Larni Member (Idle past 164 days) Posts: 4000 From: Liverpool Joined:
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No other field of science is based on a fundamental theory that is unrepeatable, unfalsifiable and therefore unscientific. Can I ask what scientific discipline you hale from? I can't imagine any one with a scientific background would say this (unless it's because of religion).
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Blue Jay Member (Idle past 2698 days) Posts: 2843 From: You couldn't pronounce it with your mouthparts Joined:
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Hi, Kaichos Man.
Kaichos Man writes: What's to say Cynodonts weren't mammals? As far as I can tell from the research (correct me if I'm wrong) we can't even prove they laid eggs. They had a couple of extra bones in their jaw. Does that mean they weren't mammals? Since the term "mammal" uses the jawbone character in its definition, cynodonts are not mammals. But, it's just an arbitrary term used to represent evolutionary relationships. Cynodonts certainly were less related to everything that we call "mammals" than those mammals are to each other. That's all that matters when talking about evolution. -----
Kaichos Man writes: For example, can a mammal be egg-laying? Can a mammal be poisonous? The Platypus is both. Minor correction: the platypus is venomous, not poisonous. Poison is a defensive/passive secretion that works via ingestion. Venom is an offensive/active weapon that is injected into the bloodstream. Sorry. Pet peeve. -----
Kaichos Man writes: If Cynodontia were mammals, all arguments about their evolution of lactation become moot. Correction: if the Cynodontia were derived mammals, all arguments about their evolution of lactation become moot. But, since, even if they were mammals, they would be the earliest mammals known; they still would represent an earlier stage in mammal evolution than everything else that is a mammal, so they would still be the ideal clade in which to study the evolution of mammary secretions. Edited by Bluejay, : No reason given. -Bluejay (a.k.a. Mantis, Thylacosmilus) Darwin loves you.
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Huntard Member (Idle past 2296 days) Posts: 2870 From: Limburg, The Netherlands Joined:
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Kaichos Man writes:
Very well. Ralians. And you can prove it by naming an atheist who doesn't believe in evolution? I hunt for the truth I am the one Orgasmatron, the outstretched grasping handMy image is of agony, my servants rape the land Obsequious and arrogant, clandestine and vain Two thousand years of misery, of torture in my name Hypocrisy made paramount, paranoia the law My name is called religion, sadistic, sacred whore. -Lyrics by Lemmy Kilmister of Motorhead
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RAZD Member (Idle past 1405 days) Posts: 20714 From: the other end of the sidewalk Joined:
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Hi Kaichose Man, getting closer.
Which is what the author was attempting. I suggest you read the article again. The presence of the milk protein in all three daughter clades - eutheria (placental mammal), metatheria (marsupial mammals) and monotreme (egg laying mammals) - is indicative of common ancestry. Further development or loss of a feature after that ancestral point does not invalidate the ancestry, and marine mammals are a branch of placental mammals, well after the divide between eutheria, metatheria and monotreme .
What's to say Cynodonts weren't mammals? As far as I can tell from the research (correct me if I'm wrong) we can't even prove they laid eggs. They had a couple of extra bones in their jaw. Does that mean they weren't mammals? Are there rules a mammal has to abide by in order to be a mammal? For example, can a mammal be egg-laying? Can a mammal be poisonous? The Platypus is both. If Cynodontia were mammals, all arguments about their evolution of lactation become moot. They weren't mammals, they are ancestral to the eutheria clade, the metatheria clade, and the monotreme clade - they are older than the divisions between these later clades of animals, and this is marked by the jaw development that was completed in the mammaliforms. iirc. The platypus is a (venemous, male only) monotreme. All of these fossils also have the same developing jaw bone homologies which was completed before mammalia iirc, before becoming mammals per se and the division into the three clades. The platypus also has teeth during fetal development but loses them as they mature and their soft bill forms. The diagram again - from The origin and evolution of lactation, Anthony V Capuco and R Michael Akers
quote: The development of the jaw\ear bone structure from a reptilian 3-bone jaw + 1 attached earbone, to a mammalian single bone jaw and detached 3-bone ear occurs during the evolution from therapsida to mammaliform, including several with two jaw joints, transitional between the two basic structures. So the increased use of calcium likely occurred well before the division of the daughter clades, and their homologies in milk forms, jaw forms and other structures argue for common ancestry.. Enjoy. Edited by RAZD, : corrections per bluejay (thanks) by our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
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Blue Jay Member (Idle past 2698 days) Posts: 2843 From: You couldn't pronounce it with your mouthparts Joined:
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Hi, RAZD.
One more minor correction: you used the word "mammal" to refer to "placental mammals," but the marsupials and monotremes are also included in the clade "Mammalia." A minor point, but it might turn into a talking point if we're not careful, so I thought I should mention it. -Bluejay (a.k.a. Mantis, Thylacosmilus) Darwin loves you.
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Kaichos Man Member (Idle past 4489 days) Posts: 250 From: Tasmania, Australia Joined: |
They weren't mammals, they are ancestral to the eutheria clade, the metatheria clade, and the monotreme clade - they are older than the divisions between these later clades of animals, and this is marked by the jaw development that was completed in the mammaliforms So we can say with stone-cold certainty that cynodonts did not bear live young?
The development of the jaw\ear bone structure from a reptilian 3-bone jaw + 1 attached earbone, to a mammalian single bone jaw and detached 3-bone ear occurs during the evolution from therapsida to mammaliform, including several with two jaw joints, transitional between the two basic structures. It's such an attractive idea, isn't it? You can just see the animation; the malleus and incus falling back, shrinking down as the dentary gets bigger and bigger, and then the two small bones eventually disappear into the ear, to play a brand new role there. But if this actually happened, let's consider for a moment what is required in terms of known evolutionary mechanisms. For each small, incremental step in this process: 1. At least three simultaneous mutations must occur, two to diminish the malleus and incus, one to enlarge the dentary. 2. The mutations must be perfectly complementary, i.e. the shrinkage of the malleus and incus must be perfectly offset by the growth of the dentary, otherwise a misshapen jaw will result- clearly a survival disadvantage. 3. A survival advantage must be conferred, significant enough to reach fixation. Remember, these requirements are for each incremental step. Anyone feel up to doing the maths? The probability would obviously run into the trillions-to-one against, but that shouldn't be a problem As long as there were trillions of therapsids. "Often a cold shudder has run through me, and I have asked myself whether I may have not devoted myself to a fantasy." Charles Darwin
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Percy Member Posts: 22394 From: New Hampshire Joined: Member Rating: 5.2
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Hi Kaichos Man,
Your position is that though the fossil record indicates that some bones in the jaw evolved to become bones in the ear, the mutations and allele remixing that occur during reproduction are insufficient due to low probability to have caused this change. But yoru position is based upon a faulty understanding of how genes control growth and development. Let's say, for the sake of discussion, that you're completely correct that evolution could not have caused this change. You're still completely wrong about two things. First this:
Kaichos Man writes: 1. At least three simultaneous mutations must occur, two to diminish the malleus and incus, one to enlarge the dentary. Phenotypic change, even extremely significant phenotypic change, is not often caused by simultaneous coordinated mutations. Genes communicate instructions to the developing and growing body by generating proteins that carry "messages." Genetic changes can cause changes to these "messages" that can in turn cause changes in some or all of these three areas:
A single point mutation can easily cause a change in just one of these three areas which can in turn cause significant phenotypic change throughout the organism. It is certainly sufficient to minutely change the position and size of a few bones in the jaw. Now on to your second error:
2. The mutations must be perfectly complementary, i.e. the shrinkage of the malleus and incus must be perfectly offset by the growth of the dentary, otherwise a misshapen jaw will result- clearly a survival disadvantage. Genes are not specifications of position, shape, size and orientation. There is no gene or set of genes saying that the malleus is this long, this wide and that high with this shape, and that it is positioned at these (x,y,z) coordinates. The malleus, like all structures of organisms, is the result of the timing and concentrations of proteins and raw materials acting together in a complex dance of chemical reactions. Proteins are not carriers of messages like, "You have to move 3 centimeters to the left and grow a little spur at the bottom," and so there are no genes generating proteins to carry these messages that don't exist. There are a number of genetically based hearing impairment problems, many caused by a single mutation, that are responsible for morphological changes ranging from the subtle to the profound. Here's a picture I found at Wikipedia of someone with Waardenburg syndrome. It is usually caused by a single mutation in one of a set of related genes, and it causes widespread morphological changes such as widespread eyes, premature graying of the hair, and significant hearing impairment:
There must be many mutations and genetic variations affecting hearing, but ones that don't cause significant problems don't get studied or even noticed. Our bedroom is on the second floor, so is it some genetic difference that allows me to be kept awake by a water drip in the basement while my wife sleeps blissfully on? Did genes cause my malleus to be just a millimeter better positioned, or my stapes to be tapered in just the exact best way? Was it just normal developmental variation? Could be, but we'll never know. The point is that, even just a single point mutation can cause changes ranging from the non-existent to the subtle to the dramatic. A coordinated set of simultaneous mutations, though not impossible, is neither required, nor likely, nor thought to occur to any significant degree. --Percy
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Kaichos Man Member (Idle past 4489 days) Posts: 250 From: Tasmania, Australia Joined: |
The point is that, even just a single point mutation can cause changes ranging from the non-existent to the subtle to the dramatic. So in the case of the cynodonts, you're invoking the hopeful monster? "Often a cold shudder has run through me, and I have asked myself whether I may have not devoted myself to a fantasy." Charles Darwin
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Percy Member Posts: 22394 From: New Hampshire Joined: Member Rating: 5.2 |
Kaichos Man writes: The point is that, even just a single point mutation can cause changes ranging from the non-existent to the subtle to the dramatic. So in the case of the cynodonts, you're invoking the hopeful monster? No, of course not. I was responding to the errors in your position regarding how phenotypic change occurs through mutations and allele remixing, not making an argument about cynodonts. You mistakenly believe that each tiny little incremental change, say moving three tiny bones of the jaw by a millimeter, requires a coordinated set of simultaneous mutations. It doesn't. A single mutation can easily accomplish that much change and even far more. We see evidence of it all the time. What you need to do is examine your position in light of the fact that your supporting argument of coordinated simultaneous mutations with its associated extremely low probability is not the way anyone within biology thinks evolutionary change occurs. You can argue till the cows come home that this scenario is very unlikely, and all we can do is agree with you. That's why it isn't a scenario given any serious consideration by biologists. In other words, even if evolution is wrong, one of the things it can't possibly be wrong about is that evolutionary change occurs through multiple simultaneous coordinated mutations because that isn't a proposition that evolution accepts. It therefore makes no sense for you to offer this proposition as a reason why evolution is wrong. Or to beat this dead horse even more, it would make as much sense to argue that Christianity is wrong because Jesus didn't really spin straw into gold. You continue to make the same fundamental mistake of mustering complaints against evolution about things it doesn't say. If evolution is wrong then it can only be wrong about things it actually says, not about things you mistakenly think it says. --Percy
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