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Member (Idle past 4826 days) Posts: 360 From: Phoenix Arizona USA Joined: |
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Author | Topic: Evolving the Musculoskeletal System | |||||||||||||||||||||||||||||||||||||||||||
ICdesign Member (Idle past 4826 days) Posts: 360 From: Phoenix Arizona USA Joined: |
Whatever dude...got to go for now...
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crashfrog Member (Idle past 1496 days) Posts: 19762 From: Silver Spring, MD Joined: |
Keep going back to the first one. The Last Universal Common Ancestor, or LUCA, may have been more primitive than any living thing since, but it was an entirely fully-formed LUCA. Evolution isn't about organisms going from no-form, to half-formed blobs, to fully-formed organisms. It's about species of fully-formed organisms giving rise to fully-formed, differently-formed descendant organisms. But they're fully-formed all along the way. Fully-formed fish giving eventual rise to fully-formed lizards, by means of fully-formed intermediate forms like Tiktaalik. It's like, you get on the highway in Peoria and drive to Chicago. The highway doesn't lead from Peoria to Chi, which is like Chicago only it's only the north 20% of the city, and then 20 miles later you come to Chica, which is like Chicago only it's the entire north half of the city, then you come to Chicag, which is just like Chicago except missing Soldier's Field, and then you finally come to fully-formed Chicago. No, you get on the highway in Peoria and drive to Chicago, and on the way you pass through a town like Bloomington, which is a fully-formed Bloomington but is a lot like Peoria except with some Chicago features (better deep-dish and taller buildings), and then you pass through Joilet, which is a fully-formed Joilet but a lot like Chicago but with some features of Peoria (country music, jack-off cops.) Fully-formed towns all along the way - not snapshots of Chicago's construction history. Evolution is the same way, it's fully-formed organisms all along the way, even when those organisms are transitional forms between their ancestors and their descendants.
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scarab Junior Member (Idle past 4670 days) Posts: 5 Joined:
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Thanks for your welcoming words in your other post. I wont be able to respond to that post tonight.
The FACT is my friend, every system within our bodies is dependent on each other for survival. I think that this is true. They are dependent on each other now but our ancestors would not have needed many of the systems that we rely on today. For a start, if you are small and live in water then you don't need a heart, or lungs, or gills, or a circulatory system, or even a gut. You can exchange all waste products and gases, and intake all nutrients directly through your integument. Simple diffusion is sufficient because all cells are close to the environment. Its only when an organism gets bigger that it needs anything more sophisticated. This is because its surface area increases as the square of its length whilst its volume increases as the cube of its length. (So the surface area / volume ratio drops as the organism gets bigger. And that is a problem if you are relying on your skin to exchange substances with your environment.) This is basic, beginners biology. I don't mean this in a cheeky way but you really should read some basic biology text books, some simple undergraduate level texts, they all explain the stuff that I'm going to mention here and they will do a better job of it. The reason that you don't make much traction with these arguments is that they have all been answered long before you made them and, probably, long before you even thought of them.
Which order did the systems evolve and how would they survive the development process when they have to be complete to survive? If you want me to address the other part of your question then I will do it in another post. Its a fun topic, well its interesting but its not nearly as important as the second part of your question because that goes straight to heart of the mistakes that you are making, the conceptual hurdles that you will have to overcome to understand how evolution could work. I can see three flawed assumptions, 3 mistakes that are holding you back. 1) You assume that because something is needed now then it must always have been needed. This simply isn't true as I explained above. Small animals need very little in the way of complex systems. Our early ancestors would have been small, marine, organisms. 2) You assume that a feature must be fully developed before it can be of use to an organism. (Though I'm not sure about this. Is it one of your assumptions?) 3) You assume that an organism that has never had a feature could not survive without this feature. We know that this is nonsense because there are animals alive today that lack many of the complex systems that mammals have and yet they live just fine. :-) Our early ancestors would not have had hearts and lungs but that's OK, they didn't need them. They were small marine organisms; they weren't humans without hearts. So why did you make those mistakes? I think that you make the first mistake because you are fixated on the final product. You think that every human ancestor had to have the same requirements as humans do. They wouldn't have had the systems necessary to meet those requirements therefore they couldn't have lived. You need to realize that our ancestors go far back into deep time. They were nothing like us. (In the sense that a layman would not recognize them.) They had vastly reduced needs and could meet those needs with whatever systems they had at the time. In the earliest days those systems would have been: 'skin' ;-) I'm not sure that you make assumption 2) but I'd like to address it just in case. Its not necessary to have a fully evolved organ system in order to benefit from a partial implementation. We see this in nematodes where they have a fluid filled internal body cavity where the fluid bathes the organs and muscular contractions of the body mix the fluid. This is a simple way to transport wastes and nutrients around the body pseudocoel | anatomy | Britannica . See here for an explanation of the insect circulatory system Color Diagrams of Insect Organs and Internal Structures . This isn't a fully developed closed vessel circulatory system like vertebrates have but it does let them grow very much larger than nematodes. I gave those two examples above to demonstrate that 'partially developed' systems are of benefit to the organisms that have them but there is a second point to be learned from those examples. The point is that although large organisms depend on having good circulatory systems: small ones don't. They can get by with less but once they develop even rudimentary systems then they are able to grow in size. Once they do this they start to become dependent on those systems and will die without them. Its a seductive trap but its not a bad trade-off, I'd much rather be a human than a nematode. Your 3rd assumption is rather strange. Have I understood you correctly? Did you really think that our earliest ancestors would have died without our two pressure circulatory systems or without advanced brains and a central nervous system? Maybe the thing that I have identified as assumption 3) is really just a rephrasing of assumption 1) What do you think? Have I understood your points? Have I misrepresented them? What would you say that your assumptions were?
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Percy Member Posts: 22504 From: New Hampshire Joined: Member Rating: 4.9 |
ICDESIGN writes: As I said in Message 71, if an organism isn't fully formed from the beginning it cannot exist. Evolution doesn't produce half-formed organisms. With evolution, all successful organisms are sufficiently well adapted to their environment to reproduce. If they were half-formed they couldn't reproduce. Jar picked up a long time ago that you and Bolder-dash think evolution produces half-formed creatures, which is why he keeps asking you what happens to half-formed creatures. The answer is that they die and leave no offspring. Their genes die with them. Natural selection has passed them by and that's the end of the line.
Not one of you has yet addressed this problem. Why is that? The source of your problem is your misunderstanding of how evolution works. You are quite correct that evolution couldn't possibly work the way you think it does. We can't explain how your misconception of evolution works because we agree with you that it's quite unworkable.
Evolution doesn't produce sudden new structures.
Exactly! So how does a system that would take a vast amount of time to evolve be functionalduring the vast time of evolvement? Each tiny little change had to be sufficiently functional in its existing environment to enable the organism to survive to reproduce, otherwise the tiny little change would have died with the organism. For instance, you might ask what good is an underdeveloped hip joint that allows our legs to splay out a bit to the sides, making it impossible for us to run fast. But chimps have that kind of hip joint and they get along just fine. All the variety of systems that make up a living organism are all evolving simultaneously in tiny, tiny steps from one generation to the next. Mutations cannot be prevented and so this incremental change over time is inevitable genetically, and combined with environmental demands that changes the requirements of adaptation, morphological changes are also inevitable. --Percy
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jar Member (Idle past 423 days) Posts: 34026 From: Texas!! Joined: |
So next step headed towards Evolving the Musculoskeletal System.
What minimal systems are needed for something to be alive? Anyone so limited that they can only spell a word one way is severely handicapped! |
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ICdesign Member (Idle past 4826 days) Posts: 360 From: Phoenix Arizona USA Joined: |
Evolution is so full of double talk and blurred lines its ridiculous.
Percy writes: Evolution doesn't produce half-formed organisms So if an organism starts out fully formed with the systems it needs to survive already fully developed, that is an act of creation not evolution.
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Huntard Member (Idle past 2324 days) Posts: 2870 From: Limburg, The Netherlands Joined: |
ICDESIGN writes:
No no no no! I'll try to explain. When an organsim, for whatever reason, is born incomplete, what happens to that organism? It dies, and well before it can reproduce. This means that wahtever caused the malfunction will die with it. So if an organism starts out fully formed with the systems it needs to survive already fully developed, that is an act of creation not evolution. Remember the laryngeal nerve thread? We explained to you there that if there ever was an instance of a mutation breaking the nerve, that the organism would die before it can reproduce, and therefore the mutation would die with it. You seemed to accept that. The same thing applies here. If there ever was produced an incomplete organism, it would die before it was able to reproduce, and thus, its "faulty" genes will not be passed on, eliminating it from the population. That is what Percy meant with "evolution doesn't produce half-formed organisms". Every organism is as complete as it needs to be (this is very important) to survive. Or if it isn't, the faults will be eliminated with it, because it cannot reporduce. Please pay special attention to the "as it needs to be". If you don't quite understand how we mean that, feel free to ask more questions.
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ICdesign Member (Idle past 4826 days) Posts: 360 From: Phoenix Arizona USA Joined: |
Percy writes: If they were half-formed they couldn't reproduce. Jar picked up a long time ago that you and Bolder-dash think evolution produces half-formed creatures, which is why he keeps asking you what happens to half-formed creatures. The answer is that they die and leave no offspring The question is; how long does it take a new body part to evolve? It certainly takes longer than the life of a given organism. How does that new body part appear in the next off spring, and the next, and the next until its a full body part? We see in Message 119 how a bad mutation can show up for our viewing. Where are the examples of a mutation producing a useful new feature?
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ICdesign Member (Idle past 4826 days) Posts: 360 From: Phoenix Arizona USA Joined: |
Hi Huntard,
Remember the laryngeal nerve thread? I was just wanting to understand how you guys think. I don't agree with your conclusions because I believe everything was created suddenly. It wasn't a hill to fight to the death over for me on that issue. So do you agree with Mr Jack on Message 149? Edited by ICDESIGN, : No reason given.
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Huntard Member (Idle past 2324 days) Posts: 2870 From: Limburg, The Netherlands Joined: |
ICDESIGN writes:
Well, look at this thread the same way. We are trying to explain to you how we see things. To get you to understand how we see it. I know we probably will never convince you of the "truth" of evolution. But we can explain to you how we see things in the hope you will understand our position.
I was just wanting to understand how you guys think. I don't agree with your conclusions because I believe everything was created suddenly. It wasn't a hill to fight to the death over for me on that issue. So do you agree with Mr Jack on Message 149?
Yes. What I think he was trying to say there is that we think the first life came about through chemistry, not evolution (Which only happens after there is life). Also, even if we grant you that god only created the very first life (a position I don;t think you hold), evolution would still be responsible for everything we see after that.
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ICdesign Member (Idle past 4826 days) Posts: 360 From: Phoenix Arizona USA Joined: |
But we can explain to you how we see things in the hope you will understand our position. ten4 Mate
Also, even if we grant you that god only created the very first life (a position I don;t think you hold), evolution would still be responsible for everything we see after that. No I don't hold that position
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Meldinoor Member (Idle past 4837 days) Posts: 400 From: Colorado, USA Joined:
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Hello ICDESIGN,
ICDESIGN writes: So if an organism starts out fully formed with the systems it needs to survive already fully developed, that is an act of creation not evolution. That depends entirely on what you mean by "fully formed". If you mean "in its present condition" (i.e. a fully formed human appearing out of nowhere) then yes, it would be a miraculous act of creation. Of course, the same applies for any creature. A fully-formed lobster, honeybee, chicken, earthworm, E.Coli etc., can not appear out of nowhere fully developed, except through some form of intervention. Of course, a seriously incomplete individual, e.g. a human with no nervous system would be unable to survive. There are many parts of the human body that are indispensable to a fully developed human. These include obvious ones like the brain, the cardio-vascular systems, the spine etc. Then there are parts that aren't directly required for survival, but which confer an important evolutionary advantage, such that losing them makes life much more difficult. Your sensory organs such as your eyes, ears, nose, etc. would fall into this category. You can survive without your eyes, at least until you walk straight into an open manhole or something. In fact, many animals do get by without (or with severely reduced) eyes. Star-nosed moles and blind cavefish are examples of this. Finally, you've got parts that you could just as easily do without. Your body-hair isn't terribly important in this day and age. The appendix would be a blessing to be rid of. You don't really need those little muscles that wiggle your ears (as amusing as they may be). The reason I emphasize this distinction between indispensable, semi-dispensable, and completely dispensable parts, is that the distinction will play a role in determining what is a "fully-functioning" individual. I'm pretty sure you consider a man with reduced skin-pigmentation, or without an appendix, to be a "fully-functional" individual, as opposed to someone without a brain or nervous system. Now, when you contrast the indispensable subsystems of the human body with the more dispensable ones you'll discover something incredible. All of our truly indispensable parts are shared with many other lifeforms, and usually, the more indispensable a given part is, the more it is shared across the tree of life. Take our nervous system as an example. Not only does it have a lot in common with our close cousins, the apes, but we also share it with other mammals, reptiles, and birds. It's even shared as far as amphibians and fish. The Recurrent Laryngeal Nerve that has been the topic of another thread in which you have taken part, is an example of this. All tetrapods and fish share this indispensable feature of our immune system. The same thing applies to the musculoskeletal system. Because it is so indispensable, all tetrapods and fish share analogous systems. This implies that the musculoskeletal system has been around for a long long time. It didn't first appear in humans. Nor did it appear in apes, primates, mammals, reptiles or any tetrapod for that matter. The most distantly related animals in which it exists in analogue to the human body are primitive fish. So our skeletons must have first begun evolving early on in the evolution of fish (possibly starting with a simple notochord)*. Since skeletons were rather newfangled at the time, they would not have been as indispensable as they are now. Probably our first "skeletal" ancestors shared the waters with similar and closely related species that did not need a skeleton. As time went by, our basal skeleton design slowly added parts as they became useful. Doubtless several were evolutionary dead-ends and never went anywhere. But some managed to become highly successful, and they became the ancestors of all fish and tetrapods today. Most importantly, by the time they had become recognizable as "fish", they would have become so dependent on their skeleton that it had truly become an indispensable part. A fish that lost its skeleton would no longer be "fully-formed". And here is the message that I'm trying to convey with this rather lengthy post: The ancient ancestors of all fish were still able to go without full skeletons because to them, the skeleton was still a semi-dispensable but useful new tool for their survival. They could add parts to it or new designs willy-nilly, and possibly even lose them again. But once fish discovered a winning formula, they stuck with it and eventually became dependent on their complex musculo-skeletal system to the extent that it became indispensable to them, to tetrapods, to us. We still use a modified fish-skeleton, although of course it has changed a lot in 300 million years. The theory of evolution accounts for our many indispensable inter-working systems the same way that I just described for fish. By going back to an ancestor where these systems were not indispensable and could be evolved separately. Respectfully, -Meldinoor Edited by Meldinoor, : No reason given.
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Huntard Member (Idle past 2324 days) Posts: 2870 From: Limburg, The Netherlands Joined: |
ICDESIGN writes:
Ok. Good. I hope that, even though you'll probably never agree with us, you can follow our logic and see how we arived at the conclusions we do.
ten4 Mate No I don't hold that position
Thought not.
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ICdesign Member (Idle past 4826 days) Posts: 360 From: Phoenix Arizona USA Joined: |
Hi Meldinoor,
Thank you for you very respectful and thoughtful post. I don't have time to respond with feedback right now but I certainly will be picking your brain in the near future Respectfully,IC
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Bolder-dash Member (Idle past 3659 days) Posts: 983 From: China Joined: |
Bolder-dash - please take these issues to your New name for evolution, "The Bacteria Diet" thread. --Admin
So talk us through this Melindoor, what do YOU personally think the first mutations to those primitive fish without any skeletons at all would have looked like? Here was this soft fleshy kind of fish thing, that had no spine, and no bones of any kind. And then what do you think that very first mutation that started the whole process out looked like? Was it a piece of bone near where the spine already was? Or was it a piece of bone that started off somewhere near his belly, and then over time and many generation slowly migrated over towards his back? Do you think those early first fish with the bones near their stomach looked silly, compared to the others? Do you think the other fish laughed at him, or do you think the female fish decided he was special, and so he got a good selection advantage, and that is why more fish ended up with the bony stomach? And then, by the time it got close to his spine, to actually protect his spine, do you think that the part near the stomach started shrinking in successive generations, because by then all the men had bony stomachs so the girl fish no longer felt it was very sexy? And then, do you think the girls started choosing the guys with the bony back, because they knew one day they would have bony back children themselves, and they knew that that bony back would be a big plus in case they bumped their spines on some coral that was just started to form a few miles offshore? Do you think they knew about the spine protection it was going to give them, or do you think they just sensed it? And what about back to that first guy who got the bony stomach mutation-do you think he is sort of famous throughout the entire marine world, as the guy who started off this whole darn bone race? Do you think there is an underwater Hall of Fame for the skeleton starter? Might we even find his fossil remains one day, and have him hung in the museum of stomach bones? And how often do bony stomach mutations happen these days anyway? Are they passe? So what do you think? Do you mind painting the picture? Edited by Bolder-dash, : No reason given. Edited by Admin, : Add moderation comment.
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