Patterns and Tautologies (The Circular Logic of Homologies)

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You do also know that circular reasoning also applies to Jesus as Messiah, LORD and Saviour?

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To some degree, yes.

So you're claiming that the evidence for evolution from homologies is circular reasoning because the word 'homology' has come to mean "any similarity between characters that is due to their shared ancestry".Correct? As in, the shared ancestry is being assumed so therefore homology only comes after the theory is in place.That makes sense. But it's incorrect. The part hinting at your error is in the very Wiki sentence you quote that says "has come to mean". Which implies that the word 'homology' had a previous meaning.Let's look at the history of the homology concept: Taken from here

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The concepts of homology and analogy were well understood by the pre- (or anti-) evolutionary comparative anatomists before the general acceptance of phylogeny, and they were defined by Owen in 1843. The acceptance of evolution led to the idea that homology should be defined by common ancestry, and to the confusion between definition and explanation. The term homoplasy, introduced by Lankester in 1870, also arose from a phylogenetic explanation of homology.

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As we can see, the concept of homology (similarities of parts/structures within different organisms) was well established before evolution was introduced. It is this point in history that is being referred to when it is said that homology is strong evidence for evolution (and indeed it was one of the driving forces to accept the theory).It is only after the theory of evolution became widely accepted, because of the vast amount of other evidence as well, that the understanding of homology was discovered to come straight from the natural process of evolution itself.The history of the concept of homology even acknowledges this issues as it states "The acceptance of evolution led to the idea that homology should be defined by common ancestry, and to the confusion between definition and explanation."It is confusing, but it is not circular reasoning.The evidence and reasoning came about first, then the Theory of evolution, then the definition of 'homology' was changed to reflect it's cuase only after the overwhelming success of the Theory.Perhaps the word 'homology' should have been replaced with another, but hindsight is always 20/20.Your confusion is fully justified, but the accusation of circular reasoning is misplaced.

Not 99.99% then?I would argue that 100% of 'prophecies' that were 'fulfilled' by Jesus are circular.Evidence for birth = 100% circular.
Evidence for ministry = 100% circular.
Evidence for arrest = 100% circular.
Evidence for trial = 100% circular.
Evidence for death = 100% circular.
Evidence for Resurrection = 100% circular.
Evidence for post resurrection appearances = 100% circuluar.Doesn't leave a lot does it?Is there anything contemporary from outside of the Bible concerning the Jesus of the Gospels?

I would say unprovable rather than circular. What's missing with all that stuff is hard evidence. It's very hard to prove something that happened 2,000+ years ago, especially when it concerns miracles.But I suppose it would be circular to believe something from the gospels, since one must assume they are true in the first place before they can be taken as truth.BTW, isn't this off topic?Edited by Binary, : No reason given.

Probably Usually the admins allow 1 or 2 off topic posts if it doesn't drag the entire thread off.If you would like to discuss the circular reasoning required ot believe that Jesus was the Messiah, and is the Lord and Saviour of all who believe in Him, let me know and I'll propose a thread.Cheers

Go right ahead. I think it would be a very interesting topic for discussion. However, as someone who until now, relied as much on Jesus as I do the pumping heart in my chest, I already understand how foolish such blind faith is.

hi Bluejay - I was asked for an opinion on worldviews. Yes, I do think evolution is a worldview but because it has always been accepted popularly, and scientists have not allowed any other explanation. Or atleast - they don't take it seriously.This isn't enough to prove evolution existed, nor a great probability, logically.To me, it is much more unlikely that the designs we see in nature made themselves up. No facts I have observed show me that I must infer macro-evolution. I am content to be mistaken, but personally, I have enough studying in logic to know that it isn't a big deal to not commit to evolution, it's just that in this present day system, the most popularly accepted theory is evolution.I don't have time to debate further. If you read the thread I was posting in, particularly about defining evidence, you will see that there is absolutely no way out, when I say that there is evidence for creation. What should matter is that there is evidence for many false theories, so you can soundly conclude that evidence itself isn't that powerful to me. Afterall, induction is a mountain BECAUSE evidence is a weak consequent.

Hi, Mike. I understand. Feel free to stop by if you ever get the time, though. Well, my intention on this thread is to show that evolution is in fact based on several well-supported patterns of evidence, and not on a philosophical paradigm or worldview. I'm not so sure I agree that there is evidence for creation, but I'll give you the benefit of the doubt for the sake of argument.-----I'd like to take the opportunity to use your comment as a springboard into my basic argument on this thread, because it presents a great segue.To me, it isn't so much about the evidence itself as it is about the patterns in the evidence. When you see a series of fossils that can be lined up into a progression in which each step features a few changes, and you see it happen in dozens of different places across the fossil record, especially when the data is backed up with radiometric dating techniques, molecular clocks and what-not, it's really hard to argue against transmutation of species.Likewise, in relation to the Kid's desired topic of homology, there is a very similar pattern emerging. Let's take it from the horse perspective that he and RAZD have been arguing. Modern equids share many things in common: shape of the skull bones, tooth formula, single hoof, etc., which, as Stile has shown upthread, were called “homologies” before they were thought of as the effects of evolutionary relationships. Extrapolating the homology concept outward, we see that each animal groups closely with some, then more loosely with other groups, forming a pattern of nested hierarchies. Tapirs and rhinoceroses, for instance, share several homologies with equids (hooves, skull features, odd number of toes, etc.), but also have several distinctions (more toes, horns, trunks, differences in tooth formula, etc.). And, both of these groups can be linked to other animals based on fewer and fewer homologies, which sets up the pattern of nested hierarchies.Then, there are genetic patterns, which, contrary to the Kid's claims on other threads, have largely confirmed with morphological patterns, and still show the pattern of nested hierarchies. I will grant the Kid that there are still many instances in which genetic phylogeny contradicts morphological phylogeny, but these are still in the minority. They sometimes appear more prevalent because they are the big discoveries in biology today, while confirming the old pattern isn’t anything exciting, so news reports aren’t written and Science and Nature magazines aren’t interested in publishing them, etc.But, since we've shown how modern organisms can be arranged into nested hierarchies, it made good sense to see if the fossil organisms could also be arranged thus. And, interestingly, the fossils and extant organisms arranged into a single, contiguous pattern with a nested hierarchical structure, indicating that taxonomic hierarchies have always existed, and that modern animals are united to extinct animals by this pattern. Futhermore, transitional series like Panderichthys-Tiktaalik-Ventastega, Pakicetus-Ambulocetus-Rhodocetus-Basilosaurus, Maniraptora-Archaeopteryx-Aves, Blattaria-Cryptocercus-Mastotermes (although, granted, these series are probably not perfectly linear), show how the pattern persists unabated across any boundary a creationist could try to put up around distinct “kinds.”That is the stuff that ToE is based upon. How else could this pattern be interpreted?You would be correct, as would the Kid, in saying that evidence occasionally seems to contradict the pattern, such as in the case of convergent evolution. But again, when such contradictions arise, intensive, detailed study can generally produce enough data to strengthen on pattern and weaken the competing patterns.The giant panda, for instance, is, to all outward appearances, a bear, but shares several bafflingly similar traits with the red panda. It was long thought a procyonid, or maybe a distinct family. A rigorous, detailed series of studies throughout the eighties and nineties (such as this one), which included morphological, genetic and ecological angles, eventually determined that the giant panda is, in fact, a bear. As far as I know, the jury is not entirely in on the red panda, which may be a procyonid (raccoon-relative) or its own distinct family somewhere between bears and raccoons.And, just like you said, you'll note that there is still evidence that unites the two pandas (the sessamoid "thumb" is the best). But, when more and more data was analyzed, the pattern supporting the 'bear' hypothesis became stronger and stronger, and the pattern supporting the alternative became weaker and weaker.Likewise, creation science has been very good about bringing up anomalies and bits and pieces, but they have not been able to produce a pattern of evidence. On the other hand, evolutionary biology has produced several patterns in genetics, the fossil record, morphology, ecology, behavior, etc. in support of it.Edited by Bluejay, : Link provided twice; couple typographical errors

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Darwin loves you.

Natural selection is 'survival of the fittest'. Which ones survive?The fittest ones. How do we know that they are the fittest? Because they survive.
Actually natural selection is death of the unfit. Homology shows morphological similarities in various kinds of biological organisms due apparently to common ancestors. But it could also be a pattern based on a common designer, common programmer of the genetic code you know. There are lots of reasons to be wary of the homologies story of the evolutionist. What vestigial features are you talking about? In the human for example, name me one. No we believe in evolution therefore we believe that the oldest thing are at the bottom and the younger things are higher up.
We have index fossils to tell us approximately how old the rocks are and the index fossils are dated originally according to how old the rocks are believed to be based on the theory of evolution and the principle of uniformatarianism which is an original assumption of little value.
SO... we date the fossils according to the rocks and we date the rocks according to the fossils ..... and round and round we go. Things that look similar morphologically should be similar genetically -it's like having a similar recipe for chocolate icecream and vanilla ice cream and a less similar recipe for ministrone soup. So whether evolution from a common ancestor is the cause or whether there is a common designer causing the similarities, one would expect a similar genetic code for similar morphologies. It only looks fantastic when one doesn't consider any alternatives. I wish I could be so excited about it.

Everything in your post can be argued against. However, to avoid getting lost in the many different threads of argument I'd like to try just one. So, according to this model, a marsupial mouse will be more genetically similar to a placental mouse genetically than the marsupial mouse would be to another marsupial: say a kangaroo? After all, the two mice species look very much the same (chocolate and vanilla icecream) and the kangaroo looks very different (ministone soup).

Hi, Beretta.Thanks for your reply. Yeah, and it goes back to the circle again: how do we know it was unfit? Because it went extinct.The point is that natural selection is just a way to describe nature as a struggle for survival, and to tie that concept in with the concept of evolution (which, despite popular perception, was a growing scientific view long before Darwin came around). Much of the world saw nature as a magical thing created and maintained by gods, and natural selection presented what was really the first completely naturalistic explanation.So, really, what this tautology argument is saying isn't that NS is a tautology, but that it's common sense. You know, you could very well be right. However, in the “Beretta’s designer” thread, you haven’t been able to show that there’s a designer, so the alternatives to the ToE concept of homology kind of violate parsimony.Furthermore, the tactic I am using on this thread is to show that ToE simply interprets the evidence according to the best pattern that can be found. Using the assumptions and predictions of ToE, scientists constructed a pattern of nested hierarchies from the information gleaned in fossil and anatomical studies. Interestingly, a pattern based on morphological homologies is also largely supported by a pattern based on genetic homologies, and the nested hierarchies line up quite nicely with the patterns in the geologic layers and their radiometric dating patterns.That makes three or four patterns that largely tell the same story. That’s what evolution is based on. So, if you take the concept of homology (in the evolutionary sense) in isolation, it looks a lot like circular reasoning, but, once you compare it to the broad spectrum of other patterns, it turns out to be rather well-supported and logical.That’s what ToE is based on. I don’t know enough about human anatomy to say what may or may not be vestigial in us, but I’m pretty sure a kiwi’s wings count as vestigial. I’m also pretty sure that the dodo’s, the kakapo’s, and the lyrebird’s wings also count as vestigial, among many other kinds of birds. I’m also certain that hundreds (perhaps thousands) of species of insect have vestigial wings, centipedes have vestigial eyes, blind cave fish have eye sockets without any eyes, etc.Vestigial features follow logically from the concept of homology. When you compare a whale to an ungulate, you see a lot of similarities in metabolism, internal organs, reproduction, etc. Then, you find a fossil that shares features with both groups, which, according to radiometric dating, comes from a timeframe shortly before either specialized group appears in the fossil record, then compare the two crown groups genetically, and you once again have about three or four patterns that are all telling a similar (if not identical) story.Again, that’s what ToE is based on.It’s not perfect evidence, and each of your claims against each idea may have merit in isolation, but, when all the imperfect patterns are superimposed, and a compromise between them is worked out, the imperfection begins to erode away. That’s what science does. No, that’s what science is.You, like every creationist, are likely going to argue that “vestigial features” must be completely without function. This argument is based completely on semantics, because “vestigial” implies uselessness. But, that doesn’t change the fact that a whale’s hindlimbs are much smaller than any other mammal’s hindlimbs, which, given the three or four patterns of development I have shown you, suggests that the whale’s limbs have atrophied. “Vestige” means something akin to “remains,” which is an excellent description of the tiny hindlimbs of the whale. You’re right: that’s what every palaeontologist drills into the minds of his interns and student employees before each dig out in the desert. And, that’s the only thing that’s holding the fragile frame of ToE up.In case you couldn’t tell, that paragraph was sarcasm.Once again, the overarching patterns in the evidence show that older rocks generally rest below younger rocks, and that older rocks hold fossil organisms that are less evolutionarily derived than younger rocks. The patterns show this remarkably well (although not perfectly), but, once again, each pattern can be used to bolster the weaknesses of each other pattern, and each task can be solved “democratically,” as in my panda example two messages upthread. In this way, we can establish which bits of evidence are anomalies and which are normal: by comparing each to this network of evidence patterns we have established. Gradually, we come to see where the evidence strongly favors a certain explanation, and that is the explanation we go for.So, all these things that the Kid brought up are just attempts to isolate pieces of a vast, well-supported mosaic of largely conforming evidence, and ignore all the outside support. You just can’t do that, because, the evolutionary model is based on patterns in all fields that conform to one another, whereas the creationist model is based on anomalies in all fields which do not conform to one another.How can you explain that? Granted. But, what about the parts of the genome that aren’t part of the genetic “recipe” you’ve proposed? Such as the parts that don’t really do much at all. How come those consistently reflect the evolutionary pattern provided by the morphological and functional genetic patterns? Surely it has nothing to do with your morphological “recipe?”Furthermore, do organisms that look alike on the outside have to have similar suites of immunological proteins and what-not? Because, they generally do have similar suites of immunological proteins. It seems to me that those genetics should more reflect the environment in which the organism lives than it’s morphological similarity, because the immune system should be geared toward the pathogens in its environment, right? But, nope, a coyote’s immune system produces proteins like an African hunting dog’s, not like an American jackrabbit’s, or a rattlesnake’s, or a pronghorn’s.It seems to me that genetics and morphology actually, legitimately do represent two distinct patterns, which just happen to have a broad level of overlap due to the large amount of control one has over the other. But, the unrelated portions also tend to conform to one another’s pattern.

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Darwin loves you.

The coccyx, remains of a tail + the muscles used to move the tail.

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There is no better love between 2 people than mutual respect for each other WT Young, 2002Who gave anyone the authority to call me an authority on anything. WT Young, 1969

The only people that believe the coccyx to be vestigial are those that believe that we once had tails.As a modern embryology textbook notes, ”Rarely a caudal appendage is found at birth. Such structures are of varied origin (some are teratomata); they practically never contain skeletal elements and are in no sense tails.’Most of us have four coccygeal vertebrae; a small percent of people have five and a few have three.
Unnecessary removal of part of the coccyx can have potentially tragic consequences.
In the past, bolstered by the idea that this organ was vestigial and unneeded, surgeons would sometimes remove a person’s coccyx peremptorily (as was once done routinely with tonsils). But this results in severe problems for the patient, because the coccyx serves as a crucial anchor point for various important muscle groups. Victims of coccygectomy (tailbone removal) in the past have had as a consequence difficulty sitting down and standing up, difficulty giving birth, and difficulty getting to the toilet in time.
Take it away and patients complain; indeed the operation for its removal has time and again fallen into disrepute, only to be revived by some naive surgeon who really believes what the biologists have told him about this useless ”rudiment'.In a high percentage of cases, people with a caudal appendage will also have another medical condition,such as spina bifida, in which a vertebra is incompletely closed.Edited by Beretta, : grammar

I'll do you better than just one and name six limited to just muscles.Originally posted to WorldWideWord on May 10, 2008.The concept of vestigial organs provides strong evidence for evolution and is clearly a threat to any argument concerning the special creation or special design of the various categories of organisms unless that concept allows for evolution. It is considered such a threat that those who believe in special creation via continuous interference in biologic history are compelled to state that there are no vestigial organs whatsoever. See Do Any Vestigial Organs Exist in Humans? | Answers in Genesis for an example of this false assertion along with some other desperate, irrational and baseless statements.Arguments against the evolutionary explanation for vestiges such as the supposed necessity of the appendix and the coccyx abound in anti-evolution literature. Less substantial excuses are also made for those vestiges that are more difficult to explain away, such as wisdom teeth or nictating membranes. However one category of vestiges stands out as being virtually impossible to dismiss, which is the existence/absence of various vestigial muscles.The central problem with certain vestigial muscles is that substantial percentages of the population completely lack the muscle in question. How can one assert that a given vestige is helpful or even necessary for a given creature when it is not even present at birth?In humans there are several vestigial muscles that are absent in a considerable percentage of the population. They include:Darwin's Point or tubercle, absent in 90% of humans.
The Palmaris muscle, absent in 11% of humans.
The Plantaris muscle, absent in 9% of humans.
The Pyramidalis Muscle, absent in 20% of humans.
The Subclavius muscle, don’t have a figure yet.
Vibrissal capsular muscles, absent in 65% of humans.To look at a few more closely:The Plantaris Muscle is used in swinging in trees by the feet as seen in most non-human primates.From Those Naughty Vestigial Bits in Skeptic Report.

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Dr. Richard Brown of Bristol, UK, submits the following: Ever since I first dissected the plantaris muscle in the human calf as a medical student, I have been a convinced evolutionist. In the monkey it is a useful muscle which causes all the digits to flex at once, and thus is useful in swinging from trees by the feet. In the human it is atrophied, may be absent, and does not even reach the toes, but disappears into the Achilles tendon. There is no sensible reason for its existence in the human, except a common ancestry with monkeys. Try telling that to a creationist, however. In my experience they change the subject!

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Vibrissal capsular muscles are used in other mammals in the movement of sinus hairs.From the abstract of Vestiges of Vibrissal Capsular Muscles Exist in the Human Upper Lip in Clinical Anatomy v.20 issue 6, 25 April 2007.

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In nonhuman mammals, sinus hairs grow around the nostrils and serve for tactile sensation. The hair follicles of sinus hairs are rooted in vibrissal capsular muscles connected to the underlying, deeper orbicularis oris, thereby enabling the voluntary movement of sinus hairs. These vibrissal capsular muscles as well as the sinus hairs are believed to have been lost during human evolution, and no previous reports can be found on the existence of vestiges of sinus hairs in humans. Our study, however, has now verified the existence of vestigial muscles of vibrissae in the human upper lip. Using conventional histological techniques, microscopic observations were made on specimens obtained from the upper lips of human adult cadavers. In 35% of these individuals, several striated muscle fascicles diverging from the underlying orbicularis oris and reaching the hair follicles were observed. Histological findings of the vibrissal capsular muscle complex suggest that these fascicles are a vestigial remnant of the sinus hair muscle.

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So here is the big problem, how can necessary and absent be synonyms in creotalk? What does this say about following any supposed law of noncontradiction?Now remember, in order to satisfactorily debunk the concept of evolution via the lack of vestigial structures, every single one of these must be shown to have a current function, including the significant percentage of situations where the vestigial structure does not even exist.Edited by anglagard, : word that last sentence a little better than in original.

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Read not to contradict and confute, not to believe and take for granted, not to find talk and discourse, but to weigh and consider - Francis BaconThe more we understand particular things, the more we understand God - Spinoza

Hi Beretta,I like that you are using unattributed creationists from the 60's as your sources, it suggests a real interest in a proper scientific discussion.Your statement ... Seems hauntingly similar to the quote given on this page at 'Creation On The Web'. Is this coincidence? It seems unlikely since the rest of your post seems to have been directly lifted from the following paragraph. As far as I can tell you seem to have absolutely no supporting evidence for your claims about coccygectomy.Do you have anything from the actual medical literature covering these preemptive coccygectomies? By far the majority of stuff I can find is to do with treating coccydynia, although I can see how a partial coccygectomy could accompany removal of a caudal appendage. There certainly doesn't seem to be anything suggestive of coccygectomy ever being treated as equivalent to a tonsilectomy.But apart from that, well done on once again showing that creationists prefer cutting and pasting from unattributed sources to debate.TTFN,WK