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Author | Topic: Vestiges | |||||||||||||||||||||||
derwood Member (Idle past 1876 days) Posts: 1457 Joined: |
quote: The extensor coccygis is not on your linked page. See (emphases mine) Gray's Anatomy, 15th Edition. (Chancellor Press, 1985) "Extensor Coccygis is a slender muscular fasciculus, occasionally present, which extends over the lower part of the posterior surface of the sacrum and coccyx. It arises by tendinous fibres from the last bone of the sacrum, or first piece of the coccyx, and passes downwards to be inserted into the lower part of the coccyx. It is a rudiment of the Extensor muscle of the caudal vertebrae in the lower animals." A muscle that attaches to the caudal sacrum and the coccyx can have only one function - to extend the coccyx. Can you extend your coccyx? No? maybe you do not have an EC. Or maybe the EC you do have does not function. Take your pick...
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TrueCreation Inactive Member |
"A muscle that attaches to the caudal sacrum and the coccyx can have only one function - to extend the coccyx. Can you extend your coccyx? No? maybe you do not have an EC. Or maybe the EC you do have does not function. Take your pick..."
--I cannot extend it no, muscle attachments are not in the correct position for it to have this assistance within the limits of muscle ability in this particular location. Muscles pull and relax, they cannot push. However I can pull my coccyx forward. The Coccygeus of the pelvic diaphragm (synonymous with extensor coccygis) is a 'Small triangular muscle lying posterior to levator ani; forms posterior part of pelvic diaphragm. Its function is to assist 'levator ani in supporting pelvic viscera; supports coccyx and pulls it forward after it has been reflected posteriorly by defecation and childbirth. Human Anatomy and Physiology Second Edition - Elaine N. Marieb; Pg 308-309 --I had found your reference interesting while also puzzling. However I do see it labeled as a '15th edition'. The original book has the copyright as follows: Henry Gray (1821—1865). Anatomy of the Human Body. 1918. This I think we can all agree on is a far from sufficient and reliable text despite its possible slight editing (from which this quote has not been). Please see:
http://www.bartleby.com/107/115.html ------------------ [This message has been edited by TrueCreation, 05-06-2002]
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nator Member (Idle past 2170 days) Posts: 12961 From: Ann Arbor Joined: |
quote: LOL! Gray's anatomy is probably the most widely-used and respected humananatomy book in the world and is used as a textbook in probably every major medical school. It is certainly a reliable source. ROTFLMAO!! Oh, ant BTW, here is a cut n paste from the site you directed us to: "The Extensor coccygis is a slender muscular fasciculus, which is not always present; it extends over the lower part of the posterior surface of the sacrum and coccyx. It arises by tendinous fibers from the last segment of the sacrum, or first piece of the coccyx, and passes downward to be inserted into the lower part of the coccyx. It is a rudiment of the Extensor muscle of the caudal vertebr of the lower animals." [This message has been edited by schrafinator, 05-06-2002]
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TrueCreation Inactive Member |
"Sorry, I have been flying cross country doing the business trip thing so I have not been able to look at either your physiology/anatomy book re: the calf muscle or to further research the wisdom teeth in certian primative peoples. Not to mention being tired and lagged."
--No problem, too bad I don't have this good of an excuse though. "However, you did appear to agree with me w.r.t. the goosebumps (the hair standing in homo sapiens is so minor and small as to be unlikely to be a communacative reaction). Likewise the decrease in molar teeth in different groups which no longer use them would also fit into vestigial or partial vestigial traits."--Yes they very well technically may be vestigial. "I will see what I can do later today or tommorrow."--Take your time. ------------------
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derwood Member (Idle past 1876 days) Posts: 1457 Joined: |
Gray's Anatomy insufficient???
LOL!!! Get a grip, TC.... And as has been pointed out, your 'rebuttal' was severely lacking.
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TrueCreation Inactive Member |
"Ut, TC, the extensor muscle which is sometimes present originates at the top of the coccyx and inserts at the end of the tailbone. It's only function could be to contract and extend the end of the tail. Since all of our tail vertibrae are fused, you couldn't move it if you wanted to."
--I couldn't move it if I wanted to? I do all the time, most particularly when I am on the pot, which my coccygeus of the pelvic diaphragm helps me with every now and then as Gray's points out. "All that stuff you copied from that anatomy website is irrelevant to the particular muscle we are talking about.--Not technically, however I was extrapolating on the wrong muscle, my mistake. "You have not addressed the fact that it isn't even present in some people, or present and quite undeveloped in others. Either way, it has no use because the vertibrae are all fused."--See above. "LOL! Gray's anatomy is probably the most widely-used and respected humananatomy book in the world and is used as a textbook in probably every major medical school. It is certainly a reliable source. ROTFLMAO!!"--We don't have to be arrogant schraftinator. I don't think we are using copies of what was published in the mid 1800's are we? I haven't much of a problem in agreeing with its statement accept that is a rudiment of the caudle vertebrae of the lower animals. Is Gray's anatomy the only published book with reference to the extensor coccygis? ------------------
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TrueCreation Inactive Member |
"Get a grip, TC....
And as has been pointed out, your 'rebuttal' was severely lacking."--Leave the arrogance at the door please SLP, you have intelligent arguments, though your bias kicks in whenever you get the chance to run your mouth, (or run your keyboard) this isn't very much help to a persons credibility. I am quite sure you wouldn't talk this way to your fellow Evo's whether they made this mistake or not. Basicaly I would most like the same respect you show yourself here in post 15: http://www.evcforum.net/cgi-bin/dm.cgi?action=page&f=17&t=25&p=1 quote: --And it was lacking because I did not address the correct muscle. ------------------ [This message has been edited by TrueCreation, 05-08-2002]
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nator Member (Idle past 2170 days) Posts: 12961 From: Ann Arbor Joined: |
quote: Look, YOU are the one who questioned the reliability of Gray's. You are the one who took this biology topic on, and so you took the chance on being gravely wrong when you criticized this particular, extremely fundamental and well-known source. Sorry that you feel a little stung, but it was pretty funny.
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TrueCreation Inactive Member |
"You can't EXTEND your coccyx/tail, TC, and this is what the vestigial muscle, sometimes completely absent and in all cases completely functionless, would be for.
So, why do we have (or not) this vestigial muscle at all if we never had to EXTEND our once not-fused tails?"--Define 'extend', because I do not know of a mammal that can 'extend'(ie, to make longer) their tale, not to mention a close relative. --A muscle posterior the coccyx and sacrum, attached to the bottom and top of the coccyx, can only pull, and thus retract the coccyx segmented bone. How does this muscle at all make it able to 'extend' even if the bones were not fused. ------------------
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nator Member (Idle past 2170 days) Posts: 12961 From: Ann Arbor Joined: |
quote: By "extend" I mean "lift". There are muscles in a cat or dog which allows them to tuck their tail, and different to lift their tails up over their backs. (added by edit after I thought about it: "Extend" refers to the joint, not the muscle.) The tail extensor muscle in an animal, and the one we have been talking about, works to lift the tail up as opposed to down or side to side. You cannot lift/extend your coccyx out and away from your body because the extensor muscle is either incomplete (vestigial) or missing. So, TC, why is this muscle, which is the exact same muscle which lifts/extends the tail in other species which have functional tails, either undeveloped or missing in some people if we didn't used to have tails somewhere back in our evolutionary history? Why, IOW, does it look like we used to have tails if we didn't? ------------------"We will still have perfect freedom to hold contrary views of our own, but to simply close our minds to the knowledge painstakingly accumulated by hundreds of thousands of scientists over long centuries is to deliberately decide to be ignorant and narrow- minded." -Steve Allen, from "Dumbth" [This message has been edited by schrafinator, 05-13-2002]
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Philip Member (Idle past 4723 days) Posts: 656 From: Albertville, AL, USA Joined: |
In the leg, the Plantaris muscle (within the calf) is sometimes double and sometimes wanting (Grey’s Anatomy),
but in all cases serves with the gastrocs and soleus to aid muscular action of ankle extension, and in fascial and ligamentous stability of those muscles for passive strength, etc.. Its surgical removal is seemingly of disadvantage to those individuals that incurr it. In the foot, there are muscles that are not always present, in perhaps 25% of the population: ‘peroneous tertius’, and/or a ‘hallux’ accessory slip is absent, for example. There are numerous other (genetic) variations/variants (not mutations) of pedal muscles, that may or may not seem to compensate biomechanically for humans per se, but if surgically removed they do become a disadvantage to the individual incurring the removal. Also, there are numerous apparently arbitrary accessory ossicles (little bones) that appear in practically all individuals and populations, some more than others, and that seem to provide insignificant benefits to those that own them. But, again their surgical removal usually incurs disadvantage to the human individual (vs. population per se). They rarely ever detract from the intricately harmonious pedal biomechanics. That they, too, existed in ‘ape-like’ ancestors seems an arbitrary significance. All these accessory bones and muscles, like the coccyx msc. in the pelvis, are musculoskeletal variations that are ‘built into’ the gene-pool only, and are never ‘gross’ DNA-mutations at present. To say more of these observed variations seems to be forcing a mutationalist argument. Consider that some humans have brown eyes, perhaps 25% have blue. Should I argue that blue eyes or brown ones are vestigiloid? What about David Bowey who has one of each? Each animal will probably have its has unique variations, too. What is significant is that all species of ‘upper’ level organisms are observed to be irreducible in their essential biomechanical complexity (to say the least), and qualify as gross ICs, from a surgical perspective. On top of this there are infinitely numerous other neurovascular non-mutant variations peculiar to some individuals and/or populations. The non-mutant variations in a species genome seem almost infinite, while preserving the complex biomechanics of that species. Are any of these actually mutants in nature? Seems impossible. They are all mere genetic variations.
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nator Member (Idle past 2170 days) Posts: 12961 From: Ann Arbor Joined: |
The construction of the human foot is not irreducably complex. It is quite explainable using comparative anatomy.
Besides, my point with TC is that he doesn't accept that the extensor coccygis is a vestigial muscle; an evolutionary leftover from when our ancestors had tails. I have been trying to get TC to explain why some of us (not all) have a muscle which is uset to lift our "tails" up over our backs when our "tail" verteba are fused into a coccyx. If humans were specially created without tails, why would God put the appearance of an evolutionary history of tails right there in our backsides, plain as day? Why are babies with tails born every so often? I am also wondering about your cute use of the word "mutationalist". What does it mean? Do you deny that mutations occur? That would be odd, because we observe them to happen all the time. they are demonstrable, and cumulative. ------------------"We will still have perfect freedom to hold contrary views of our own, but to simply close our minds to the knowledge painstakingly accumulated by hundreds of thousands of scientists over long centuries is to deliberately decide to be ignorant and narrow- minded." -Steve Allen, from "Dumbth" [This message has been edited by schrafinator, 05-13-2002]
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Mister Pamboli Member (Idle past 7577 days) Posts: 634 From: Washington, USA Joined: |
quote: I never cease to be amazed by what one can find on the web. By mistake I typed coccyx into my browser's address bar rather than the google toolbar - and was redirected to http://www.coccyx.org !! Talk about specialised! It does have some interesting references to papers dealing with all things coccygeal, some of which mention human tails. O and did you know that coccyx comes from Greek ‘kokkoux’ (cuckoo), as the human tailbone resembles the shape of a cuckoo’s beak?
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Peter Member (Idle past 1479 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
quote: Could you explain that a bit more ? The question I asked (to re-phrase) is :: If animals were created in (roughly) their current form,why would there be aspects which could be viewed as vestigial ? Why would a designer include a smaller/less-functional etc.version of something from another creature, when it is of limited use to the new design ? The coccyx is a good illustration because there is (in a designwhich does not require a tail) no need for it at all. If you were to design a number of creatures, I can accept that youmight re-use the basic body geometry and skeletal concept, but why use a skeletal structure for an upright creature that is far better suited to four feet ?
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Dr_Tazimus_maximus Member (Idle past 3217 days) Posts: 402 From: Gaithersburg, MD, USA Joined: |
quote: First I would like to see the studies where these removals are a disadvantage. I would hazard a guess here that the removal of these muscles in an adult would be far more of a problem than in an infant; in otherwords, it would be very much dependent on the muscle mass and attachment(s) of the surrounding muscles that would be called on to take over for the removed ones.
quote: Same as above with another comment. If you are going to say that the assignment of the significance with apes is arbitrary then you need to address what would happen to the physical abilities of the ape if the muscle is removed from that species. If you remove certian muscles from the foot of an ape (muscles that have been discussed as being veistigial in man) then they (the ape) can not grasp a tree limb with that foot and would be placed at a severe disadvantage. This argues against your position.
quote: First, in your model where does the variation come from. If you are talking about a strict creationist model (God creating two of each animal, or only two of each animal surviving the mythical flood) then there would be NO variation to account for these differences, only two alleles for each gene. This alone blows your gene pool variation without mutation out of the water. Second, what do you mean by "gross" mutation, sounds to me like you are building an escape hatch into your arguement quote: Well, first off I do not believe that eye color has much function anyway so the statement is baseless on the face of it (ie vestigiloid is a structure which no longer has a funtion, if there never was a funtion it can never be vestigiloid). Second, the mutation for this one is well defined so there is another harpoon in your white whale, or in this case while elephant, of an arguement.
quote: Actually if any single attribute is examined then the variation is quite limited, and it is limited by: 1) the number of alleles directly responsible for that attribute, and 2) the interaction of the alleles that effect the attribute indirectly. The number of alleles for blood type is quite well defined and argues against your position, the number of alleles for the enzyme alchohol dehydrogenase is reasonably well defined and argues against your position, the number of alleles for CD148 (a membrane protein) is reasonably well defined and argues against your position. These can all be found at
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed with a variety of search terms. Philip, it appears to me that you are arguing from a position of incredulity. That is not a sound basis for belief, and really not a sound basis for science. You also appear to support mutations when they support your arguement and then turn around and dismiss them, and the implications of them. That is also not a basis for a sound scientific arguement. Finally, I would like to know how you explain away pseudo-genes. I mentioned them to you near the start of this thread and have recieved no response. Many of these genes, hemoglobin pseudo-genes for example, contain large chunks of expressed gene including splice junctions to removed introns and yet lack control sequences that allow for expression. A wonderful example is the gene missing in humans for the sysnthesis of Vitamin C. The remaining chunk is in effect a pseudo-gene, the active gene expresses an enzyme called gulonolactone oxidase, that is present in apes but not in us. This is why we require Vitamin C. A perfect example of a vestigiloid gene that would do use a world of good, ....if it were not vestigiloid http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ uids=9296457&dopt=Abstract Looks to me, and to most molecular biologists, that our DNA is littered with vestigial gene fragments. ------------------"Chance favors the prepared mind." L. Pasteur Taz [This message has been edited by Dr_Tazimus_maximus, 05-14-2002]
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