Posted by: paulgarner | January 5, 2010

Musings on loopy laryngeal nerves

One of the most intriguing arguments in support of evolution comes from biological features or structures that are suggestive of historical contingency. Since evolution involves the modification of pre-existing structures to give rise to new ones, certain constraints are imposed on the possible evolutionary pathways that may be taken. Some structures are said to retain a legacy of these constraints in their current form or configuration, and are thus understood as ‘accidents of history’ or ‘suboptimal improvisations’. For example, Richard Dawkins has been making much recently about the route taken by the recurrent laryngeal nerve in giraffes (Giraffa camelopardalis). The laryngeal nerve, which serves the larynx, originates as a branch of the vagus nerve in the neck. However, it then passes down into the chest, loops under the posterior side of the aorta, and then travels back up to the larynx – in the giraffe, a diversion of some 3 to 5 metres. Dawkins’ argument is that the laryngeal nerve takes this much-longer-than-necessary route because the giraffe evolved from short-necked ancestors.

Now as I thought about this, it occurred to me that the same hypothesis might apply even from a creationist perspective. Assuming, as many creationists do, that the created kind (or baramin) is approximately equivalent to the taxonomic rank of family, i.e. encompassing all the Giraffidae, and hypothesising, as many creationists do, that the Cenozoic sediments which contain giraffid fossils were laid down in depositional events after the global Flood, we might conclude that the fossil record of giraffids represents post-Flood intrabaraminic (‘within-kind’) diversification. Furthermore, recognising that the earliest known Cenozoic giraffids (as well as the only other living member of that family, the okapi) possess short necks, we might well infer that the ancestral giraffe on the ark was short-necked and subsequently diversified into longer-necked forms, thus giving rise to a historically contingent pathway of the laryngeal nerve.

Of course, that still leaves the question of why the recurrent laryngeal nerve takes a slightly circuitous route even in mammals with short necks, including presumably the ancestral giraffid. Perhaps there’s a functional reason, but, if so, it’s not obvious what it is (ideas on a postcard, please). Some might attribute it to the inscrutability of God’s will, but that doesn’t seem very satisfying. However, the point here is that, unless we assume species fixity, the route taken by the recurrent laryngeal nerve does not help us to discriminate between creationist and evolutionist explanations of the origin of the modern giraffe as Dawkins seems to have assumed.

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Responses

  1. How quickly must the giraffes have evolved? By 1460 BC, at the latest, giraffes are recorded by Egyptians, and there are earlier drawings of them elsewhere in Africa.

    If the Flood happened around 2300 BC, the Cenozoic Miocene giraffid fossils are laid down at some point afterward. (Miocene being later in the Cenozoic)

    The pre-horses found in America are in the Cenozoic Eocene – early in the Cenozoic layers. They must have taken at least several hundred years to travel tens of thousands of miles (including crossing an ocean) to get from the Ark to the US.

    So, the Cenozoic got laid down from some point after 2300 BC to what, 1700 BC? That gives horses a couple hundred years to migrate a couple thousand miles and across an ocean to get buried in the Eocene part of the Cenozoic in America.

    The giraffid fossils are found in the Miocene and Pliocene parts of the Cenozoic – the much later parts. That leaves almost no time at all for the giraffe to evolve from the fossils you mention (which must have been laid down sometime around 2000-1800 BC) to the modern form recorded by Egyptians around 1460 BC – only 300 to 500 years.

    Do I understand you properly?

    • You’re right to say that there’s a pretty tight ‘time window’ during which the ancestral giraffids (or equids or whatever) must have migrated and diversified after the Flood. Sanders (2009 p.67) proposed a provisional correlation between Cenozoic radiometric dates and the biblical timescale, in which the Miocene began about 90 to 260 years after the Flood and the Pleistocene began around 310 years after the Flood. You might want to take a look at Todd Wood’s responses to very similar questions from Kevin N about the horse series.

      Reference

      Sanders R. 2009. Oceanic islands and their plants as a test of post-Flood speciation, in: Wood T. C. and Garner P. A. (editors), Genesis Kinds: Creationism and the Origin of Species, CORE Issues in Creation Number 5, Wipf & Stock, Eugene, pp.65-112.

  2. Once upon a time, I suspect that Dawkins’ argument would have carried more weight, but now that modern creationists are coming to accept more and more evolution (within ‘kinds’), I guess such an argument doesn’t hold as much sway.
    I guess the question now is whether the same “suboptimal improvisations” used as evidence for evolution within a baramin can also be used as evidence for evolution between baramins. There are many examples out there (see, for example, Neil Shubin’s “Your Inner Fish”).

    • ‘Suboptimal improvisations’ that arose within baramins ( and I suspect that the panda’s pseudothumb might be one of those as well) shouldn’t really pose much of a problem for creationists. The challenge will be to understand or explain those that appear to be transbaraminic (did I just coin a new word?). By the way, as I’ve argued before, the idea of biological change within broad limits has a long historical pedigree and isn’t confined solely to modern creationists.

  3. I’m curious to know how baraminologists come to accept that giraffes are descended from short-necked fossil species to begin with. My understanding of baraminology is that baramins are inferred on the basis of breeding experiments. Fossils don’t breed, so how can fossils be incorporated into baraminology in the first place?

    • Various additive and subtractive criteria are applied to establish membership of baramins, including but not limited to hybridisation. Palaeontological and morphological evidence also play a role. You may find this introduction to baraminology useful.

      • Thanks again for the response, Paul. I checked out the link you provided me with regards to the criteria used to infer baramins, but unfortunately, I found it more confusing than anything. As I understand it, the search for baramins starts with a particular assumption that the Genesis “kind” is a real, discrete unit of biology. It strikes me that in order to test such an assumption, we must develop a means of distinguishing between supposed baramins without referring back to the Bible (lest the search for baramins becomes a circular argument). But on the link you provided, one of the criteria for distinguishing baramins is “scriptural claims to discontinuity” (e.g., humans do not belong to the same baramin as apes because the Bible says they are a separate creation). This strikes me as being completely circular (baramins exist because the Bible says so; evidence for this interpretation can be found in the Bible). If I’m confusing the issue, please let me know where. But in the meantime, the question still rattling around in my head is this: How can we objectively test for the existence of biblical “kinds” in the first place?

        [Note: See PG's reply below.]

        • [Note: This is in response to Jordan's comment above]

          Well, baraminology is an explicitly young-age creationist systematic method and thus it takes into account relevant biblical data where it is available. However, baraminologists are interested in applying as wide a range of criteria as possible in determining the membership of baramins – hybridisation, morphological, molecular and palaeontological evidence, in addition to biblical information. In the case of giraffids, I’m pretty sure the Bible won’t tell us whether Samotherium and Giraffa belong to the same baramin, and so we’ll have to decide that based on other evidence.

          • Thanks again, Paul. Just one last question, then: Is baraminology falsifiable? If we’re unwilling reexamine our initial assumption that Genesis “kinds” are real biological units in light of new evidence, it strikes me that it is not. Again, if I’m wrong, please correct me. I’m still trying to wrap my head around this stuff.

            • The assumption that biological discontinuity is a real phenomenon is basic to baraminology, just as the assumption of universal common ancestry is basic to evolutionary systematics. However, specific baraminological hypotheses are falsifiable and can be tested against the evidence. I suppose it’s possible that our search for discontinuity might reveal only continuity, although that doesn’t seem to reflect what we actually see. Rather, when we look for discontinuity we do seem to find evidence of it.

              • I guess my point is that we DON’T see discontinuity in the fossil record, though, Paul. There are excellent examples of intermediate morphologies in the fossil record, including those that span currently identified baramins. I asked Todd Wood about these intermediate forms a while ago (http://toddcwood.blogspot.com/2009/12/what-about-transitional-forms.html) and he admitted that he could not account for them within a baraminological framework. Perhaps the best evidence for continuity can be seen in the ape-human transition, as Todd has admitted in print (http://www.creationbiology.org/content.aspx?page_id=22&club_id=201240&module_id=36954). This is the basis on which common ancestry is inferred (as is the objective nested hierarchy into which life is arranged) — it isn’t simply an assumption, as you say.
                So we DO have excellent evidence for inter-baraminic continuity in the fossil record (it’s the same kind of evidence that you used to link modern giraffes with their short-necked ancestors), which I would think should cast serious doubt on the biological reality of “kinds” for all of us. The fact that baraminologists continue to insist that baramins are objective and real is what makes me think the field is ultimately untestable since the evidence isn’t allowed to challenge its basic assumptions.

                • Actually I think that discontinuity is a pretty pervasive feature of the fossil record. Yes, there are morphological intermediates both in the fossil record and in the living world – although most of them cannot easily be interpreted as evolutionary intermediates. More challenging are the stratomorphic intermediates in the fossil record that seem to connect ancestral and descendant groups, but there are far fewer of them than one might expect from evolutionary theory. Of those, some are intrabaraminic (e.g. horses) and probably document post-Flood diversification, while others may represent ecological intermediates between adjacent pre-Flood communities that were buried sequentially during the Flood. This article by Kurt Wise is a good introduction to the ‘transitional forms’ problem from a creationist perspective. It doesn’t shy away from the difficult questions, while offering encouragement to creationists in their search for understanding.

                  • I hate to be a thorn in your side, Paul, but I still don’t think I’m getting an answer to my question: Is baraminology as a field falsifiable? If so, how? Clearly, intermediate forms don’t cut it since their existence doesn’t seem to trouble most baraminology proponents (except maybe Todd Wodd, who I think has a better grasp of the significance of intermediate forms than Kurt Wise, as evidenced by Wise’s… confused article. I honestly question whether he understands the difference between homology and analogy at all judging by his article in Answers).

                    [Note: See my response to Jordan's post below dated January 8, 2010 at 5.37 pm]

                    • [Note: This is in response to Jordan's post dated January 7, 2010 at 5.55 pm]

                      Jordan, I’m not at all sure what you mean when you ask whether baraminology as a field is falsifiable. As I’ve said before, specific baraminological hypotheses can be tested, and I suppose it’s possible to imagine that baraminological methods would fail to find any evidence of discontinuity whatsoever. But isn’t asking whether baraminology as a field is falsifiable a bit like asking whether cladistics as a field is falsifiable?

                    • Sorry if I’m not getting my question across clearly, Paul. I’ll try clarifying the intent of my question.
                      The search for baramins presumes that such things exist in nature; it is an assumption that stems from a particularly literal reading of Genesis. My question is whether this assumption is testable.
                      I think it is a testable assumption, and I think the Bible gives us a good test case. According to Genesis, humans were clearly created separate from all other animals, and so they should fall into a distinctly separate baramin (if such a thing exists). Yet according to the “major additive criteria” you linked to earlier, humans and apes meet two out of three of those criteria (morpho-molecular similarity and stratomorphic series), suggesting that they are, in fact, closely related. Yet baraminologists continue to insist that humans and apes belong to separate baramins despite evidence to the contrary (again, see Todd Wodd’s paper on this). This suggests to me that either the concept of baramins is unfalsifiable, or the criteria used to infer baramins are useless.
                      I’m curious to hear your thoughts on this.

                      Also, getting back to the original thread, there’s an interesting blog post by Gordon Glover over at BioLogos that addresses much the same topic:

                      http://biologos.org/blog/evolution-design-and-history/

                    • Just one quick comment because I’m a bit pressed for time: I think you should realise that to a young-age creationist like myself the claim in Scripture of discontinuity separating apes and humans counts as evidence – in fact the best evidence there is. I realise that probably won’t be very satisfying to you, but there it is. Perhaps others will want to wade in with their own thoughts and responses at this point.

                    • Thanks, Paul. I understand where you’re coming from, but if YECs are going to try to defend a literal reading of Genesis with scientific principles, doesn’t it behoove you to avoid using circular reasoning? You can’t claim that science supports the Bible if you’re using the Bible itself as evidence. That’s a logical fallacy. It seems to me that if the scientific evidence contradicts the idea that humans and apes were created separately, then we either have to reject the notion of baramins altogether (and to reexamine our interpretation of Genesis) or give up on the idea that YECism is somehow scientific.

                    • Jordan, just one point of clarification: I’m not at all interested in trying “to defend a literal reading of Genesis with scientific principles”. Rather, I accept the truth of creation by faith and investigate the world scientifically with that presuppositional basis. That’s not to say that I’m uninterested in evidence, just that my aim in scientific investigation is not “defending Genesis” or “proving Scripture”. I don’t think the Bible needs that kind of help. ;-)

                    • Jordan,
                      The creationist search for baramins does assume that they exist just like evolutionists assume that common ancestry exists. Creationists do have an historical account as a basis for their belief. Sometimes evolutionists are so lost in their paradigm that they fail to see what evidence would distinguish the two models. Forming a list of similarities between humans and chimps is not particularly helpful. If I form a list of differences, it wouldn’t be particularly helpful either. One can do that with any combination of creatures and neither side has really made a convincing case. Baraminology requires more holistic comparisons. Creationists see the obvious distinctions between Man and all other animals (in cognitive function, language ability, creativity, etc). Apes are not significantly different from other creatures in these aspects. Bipedality and morphology of the foot are much less significant differences between man and apes. The faith that naturalistic processes can bridge this gap is something I don’t have. The comparisons between humans and apes, given what we still don’t know, are not particularly convincing. They are narrow and very circumstantial. (And yes, creationists can have arguments that sometimes fall in this category too.) To be honest, I’m not convinced you are looking for answers. It sounds like you have already found the conclusion you prefer.

                      [Note: See Jordan's response above dated January 9, 2010 at 5.05 pm]

  4. About that tight window, how do you explain that the various horse fossils are found in places like North America in the Eocene layers, and still show impressive speciation?

    If the Miocene was laid down 90-260 years after the Flood, and the Eocene is earlier, that gives the horses less than 100 years to go from those original two on the Ark thousands of miles to wind up buried in North America in places like Wyoming. How is that even remotely possible?

    Those two had to populate into tens of thousands in that 100 years, while …

    they were migrating thousands of miles, across mountains, across ice sheets, across an ocean, while residual flooding is laying down soil hundreds of feet deep. (remember – they’re migrating trying to find the easiest food, not purposefully setting out to cross as much land as possible)

    And while they were doing all that, their bodies were changing all over the place – ribs coming and going, feet changing all around, teeth adjusting, size varying, vertebrae, skull shape, etc.

    And you’re saying all this took place in LESS than 100 years???

  5. Paul, I appreciate you pointing me to Dr. Wood’s blog, but his answer is:

    “… all the speciation mechanisms we know about today are not adequate to explain this kind of rapid change and we need to develop a new one.”

    He gives a couple ideas about what sort of things might be able to cause it, but clearly states we don’t see any of those mechanisms now.

    But, you’re dodging the core of my question – do you think it’s even remotely plausible that those little horses would travel the thousands of miles, across numerous mountain ranges, across land where soil is being laid down hundreds of feet deep, across ice sheets and glaciers, across oceans – all in less than 90 years?

    That’s not a genetics question, just a pure transportation question. These aren’t animals on a mission, they’re looking for food. They aren’t about to try crossing places where glaciers are forming – they couldn’t survive if they tried, which they wouldn’t. They couldn’t cross the Atlantic unless there was a land bridge at that time which I’ve never heard of. There are quite a few European mountain ranges they would have needed to cross, and then the Appalachian mountains too.

    Do you really think all of that is even remotely possible for migrating little horses in LESS than 90 years?

    • Well, I agree that we need some original thinking on speciation mechanisms and Todd Wood has given some thought as to what those mechanisms might be. Did you read his papers on altruistic genetic elements?

      On the dispersal of mammals after the Flood, I think the answer is likely to involve rafting on mats of floating vegetation, as per Wise and Croxton, although that model has yet to be developed beyond the ‘bare bones’. There’s also some interesting discussion concerning these issues in Whitmore and Wise’s paper on mammalian diversity in the Green River Formation.

      The bottom line is that, unless more work is done along these lines, we’ll never know whether it’s possible to explain mammalian diversification and migration in such a short timeframe. But I think it’s worth making the effort to find out.

      • I thought the giant plant mats were during the flood?. The animals on the Ark didn’t get off until well after the waters had receded, and thus the vegetation mats would have been gone, receding out to sea with the waters.

        The Ark landed, a couple months went by before the waters receded enough so that he couldn’t see any water around him. He waited another two months and by that time, at the rate the water was receding, any available vegetation mats would be long gone and/or grounded except in the oceans.

        That still leaves two thousand miles of Europe the horses needed to cover before they could find a vegetation mat in the Atlantic ocean. Surely that took several decades to accomplish and wouldn’t the mats have grounded by then, or at least been far away from land?

        Perhaps there was a mat in the Mediterranean. We know they didn’t jump onto a mat right away since they stayed around Ararat long enough to leave descendants in Europe.

        So that’s at least a decade to populate at least a few horses. So, wait a decade to spread the herd that expanded into Europe, then catch a mat in the Mediterranean area? Wouldn’t it be trapped in the Mediterranean, or even if it wasn’t, wouldn’t the only way animals could get onto it is if it is already grounded?

        [Note: See my response to WebMonk's post below dated January 8, 2010 at 5.26 pm]

        • [Note: This is in response to WebMonk's post dated January 8, 2010 at 3.51 pm]

          I get the impression from your opening question that you haven’t read Wise and Croxton’s paper on post-Flood rafting. I think you should. Sure, it won’t address all the criticisms you’ve brought up, some of which are valid, but it would help you to understand the model better.

          • I’ve read of two types of floating mats -

            One are oceanic floating biomes which broke up in the Flood, but which didn’t transport living creatures between continents in the post-Flood. (as I understand the theory)

            The other is made of conglomerations of floating detritus into massive floating mats which could transport some animals across oceans.

            I was referring to the second type.

            I haven’t been able to read the full papers, but I have read a variety of articles on the ideas. (If you know where electronic copies are I would be THRILLED!!!! I can’t find available paper versions, and the CDs for sale don’t look like they include the papers.)

            Suffice it to say the articles are only sketches of the “bare bones” ideas you mention, and I admit I have to make a lot of guesses about how the floating mats would function. I haven’t been able to come up with many ideas that have made the mats even vaguely probable for a large-scale dispersion mechanism.

            There are hundreds of families of animals fossilized in the North American Eocene and Myocene layers, and getting hundreds of families (many thousands of very different types of animals) onto these mats and then across oceans in such a short amount of time has blasted their possibility out of my standards for even vague possibilities.

            Maybe the papers add more details that allow the mats to work.

            Outside of mats, wouldn’t land-bridges be the only other way? For animals from the Middle East area to get to North America, they would need to cross over a land bridge following something like France-England-Greenland-Canada-US. Was there such a bridge in the immediately post-Flood world?

            • Hi WebMonk, I’m not aware of a post-Flood land bridge of the kind you’ve described. At times of low sea level stand, there would have been a land bridge, referred to as Beringia, crossing what is now the Bering Straits, which would have connected Asia with North America. For further details about the ICC proceedings in which Wise and Croxton’s paper on rafting appeared, see my reply to Jordan under my ‘Monday miscellanea’ post.

  6. Dawkins’ argument is that the laryngeal nerve takes this much-longer-than-necessary route because the giraffe evolved from short-necked ancestors.

    No, that’s not Dawkins’ argument. The actual observation (not “argument”) is that the recurrent laryngeal nerve, branch of the vagus nerve, develops in the embryo of mammals from the 6th pharyngeal arch (“gill slit”). In a developmental sequence to complicated for a comment (‘no room in this margin’), the nerve is constrained to take a circuitous path by virtue of the development of the arterial system around the heart. That circuitous path is comprehensible only in light of the constraints of historical contingency from the history of the two systems in pre-mammals, all the way back to fish-like critters.

    So it’s not just an over-simplification to say the giraffe’s nerve takes longer-than-necessary route in giraffes because they evolved from critters with shorter necks, it’s a distortion. The path of that nerve in all mammals is longer than necessary, and any creationist explanation you invent for the giraffe has to account for that fact in all mammals. Are all mammals members of the same baramin?

    • Well in the versions of the argument that I’ve seen, the point was being made in the context of the giraffe’s long neck, and that’s what I was commenting on in my post. However, I’m not sure that you’ve read very carefully the rest of what I said. I explicitly acknowledged that there’s still the problem of why the recurrent laryngeal nerve takes the route it does even in mammals with short necks. I actually think that’s a more powerful argument from an evolutionary perspective, and the emphasis upon the giraffe means that that point tends to get rather lost.

  7. [Note: This is in response to Jean Lightner's post below dated January 9, 2010 at 4.03 pm.]

    Thanks for your input, Jean. Again, I have to point out that common ancestry is not an assumption; it is a well-supported theory based on a tremendous amount of evidence. If you don’t want to take it from me, take it from YEC Todd Wood. He gets it:

    http://toddcwood.blogspot.com/2009/09/truth-about-evolution.html

    You say that I’ve already reached a conclusion concerning the validity of baraminology, and admittedly, it’s true. I don’t think it’s good science because it relies on circular reasoning: The evidence is said to support a literal interpretation of Genesis, while at the same time, a literal interpretation of Genesis is used as evidence for its own claims (it’s right there in the criteria Paul linked to earlier). That isn’t to say that I won’t change my mind, but no one here has said anything that directly addresses my concerns.

    • Evolution is a well-supported theory in exactly the same sense that spontaneous generation was a well supported theory. Lots of observations were consistent with it. Common descent is no less circular than baraminology. The major difference is that creationists are more willing to consider historical records when they develop their historical models. Evolutionists tend to follow the enlightenment pattern of assuming people in the past were ignorant and believe mythology. They then proceed to make up their own story of the past and believe it. ALL historical models have assumptions and you should be able to recognize them. Common descent is an assumption. As Todd points out (sometimes more clearly than others), there are lots of observations that can appear consistent with this assumption. I also am aware of lots of observations that are not consistent with the current neo-Darwinian model.

      • I’m not sure why you continue to press the idea that evolution is an assumption, rather than a well-evidenced theory, Jean. You appear to respect Todd Wood’s position on the matter, so I’ll quote him here: “There is evidence for evolution, gobs and gobs of it. It is not just speculation or a faith choice or an assumption or a religion” (http://toddcwood.blogspot.com/2009/09/truth-about-evolution.html). Some of the best evidence for evolution comes from the objective nested hierarchy into which life is ordered, which only descent with modification can account for. It isn’t assumed; it is inferred on the basis of the evidence.
        What I’m interested in knowing is whether the existence of baramins is an untestable assumption for those who espouse them. Case in point: the loopy path of the laryngeal nerve is cited by Paul above as evidence for the monophyly of the giraffe baramin, but as RBH pointed out subsequently, the same observation can be used to evidence the monophyly of all mammals. There’s a great video that goes into more detail here:

        I wonder if there are any baraminologists here who would be willing to seriously entertain the idea that all mammals form a unique baramin on the basis of this evidence (as they have the monophyly of the giraffes), or whether their pre-commitment to a literal Genesis would prevent them from going where the evidence from God’s creation leads. If the latter, then surely the existence of baramins is an assumption stemming from a particular reading of the Bible, rather than a robust, well-evidenced theory, no?

        • Hi Jordan, just a couple of points if I may.

          Firstly, I obviously can’t speak for Jean, but when I mentioned “the assumption of universal common ancestry” earlier in our discussion, it was in the context of evolutionary systematics. Take cladistics, for instance. The cladistic methodology is blind to discontinuity. It has no way of finding it or graphically representing it, even if it exists. For more on this, see Kurt Wise’s comments in his 1990 ICC paper on baraminology.

          Secondly, I didn’t cite the long loop in the recurrent laryngeal nerve as evidence of the monophyly of all giraffes. I was simply making the point that the existence of that loop didn’t distinguish between creationary or evolutionary explanations of the extant giraffe species, Giraffa camelopardalis, unless species fixity is assumed to represent the creationist position. Why that nerve takes such a curious route in all mammals is a separate and, I think, more interesting question.

          • Hi Paul,

            I take your point about cladistics not being able to identify discontinuity (hence phenetics), but the common thread of life was identified long before the advent of cladistics. Linnaeus first recognized the hierarchical commonalities shared by all organisms and his system of organization would not work if it were not so. I agree that different families of animals can be quite dissimilar, but the point is that despite these dissimilarities (which evolutionists would attribute to adaptive radiation rather than to special creation), there still remains underlying similarities (synapomorphies) that unite all life. The trick is to explain this nested pattern of similarities and differences with a unifying theory, and as Todd pointed out elsewhere on his blog, an appeal to a common designer doesn’t do it. (To wit, why do humans look more like apes than dogs? Is it because humans and apes share a common designer apart from dogs?)
            I also agree that the ubiquity of the recurrent laryngeal nerve among mammals is an “interesting question”. So what’s the answer, if not descent with modification? I have yet to hear one from creation scientists. This is probably the single most important question that creation science must answer if it is going to be taken seriously as an alternative to evolution.

        • While I consider Todd Wood my friend, I do not necessarily agree with everything he says (or your interpretation of what you believe he was saying in his blog). I received all 3 of my degrees from a secular university (BS in Agriculture, DVM, MS in Vet Preventive Medicine). In agriculture we are far more empirical than people who build historical models. During my coursework for my master’s degree we constantly read journal articles and were asked if the author’s conclusions followed from his research. Many times they didn’t. Also, we were always challenged to consider what other possible explanations there might be for the data collected. If I apply this secular scientific training to common ancestry explanations, it becomes obvious how weak the case is for it. After years of being taught evolution, being told there was lots of evidence, and only seeing circumstantial evidence, I finally sat in on a graduate level class on evolution. I was shocked as the teacher systematically demolished all the evidence I had learned for evolution. For example, he discussed the fact that the fossils don’t really support the gradual evolution as I was taught (Gould’s work). So some scientists suggested changes happen quite suddenly and dramatically. Many biologists didn’t like this so they suggested that life evolved elsewhere and was skyrocket to earth. I was shocked and nearly fell off my chair! Science fiction is perfectly acceptable in a science class at a major university, but creation was dismissed without any consideration. Common ancestry is dogma for the evolutionist; all evidence is interpreted through that framework regardless of how well it fits. Since I reject this assumption, I am free to see if the evidence fits another framework. I believe it fits better in the creation model. (As does what I learned in anatomy, physiology, embryology, and everyday life) You are free to disagree.

          BTW, giraffe’s are ruminant (a suborder). Ruminants share many distinctive features. For example, the ruminant stomach is distinct from all other multi-chambered stomachs. It doesn’t really compare well with that of the camelids. So I clearly see a discontinuity between ruminants and other animals when I consider the anatomy. Also, I consider it absurd that the types of differences within ruminants (or even between sheep and goats, which are monobaraminic based on hybrid data) can be explained by natural processes. Instead, designed genetic changes would be necessary if one wants to have a viable (living) animal. This is my area of research and naturalistic processes are not accounting for the patterns I see described in the literature. One technical write up I did on this can be found at: http://www.answersingenesis.org/contents/379/Genetics_of_Coat_Color_I.pdf

          • Hi Jean,
            With respect, I don’t feel the need to defend evolution (this isn’t the place for it and there are already thousands of resources that do the same thing). Suffice it to say that evolutionary theory is NOT dogma (for reasons that I already explained above and Todd explained on his blog), and that punctuated equilibrium doesn’t so much reflect rapid evolution as as it does the different rates of evolution vs. sedimentary deposition (i.e., it is an epi-phenomenon).
            I agree with you that there are differences between camels and giraffes (obviously), but if you only open your eyes to these differences, of course you’re going to see discontinuity. Camels and giraffes are both artiodactyl ungulates, though, and as such, they also share many features in common exclusive to other mammals (e.g., hooves, even toe counts, double-pulley astragalus morphology, etc.). So what of these? How do we account for those similarities? Again, the common designer argument doesn’t cut it (do giraffes and camels share a designer apart from other mammals?), so how do YECs account for the features that unite these two groups of animals? I keep asking this question, but I’ve yet to read an answer.
            I’ll also quickly point out that stomach evolution and development is quite flexible, as evidenced recently by a population of wall lizards that rapidly evolved caecal valves when transplanted to a new environment where only plants were available for food:

            http://www.pnas.org/content/105/12/4792.full

            So it really isn’t that difficult to suppose that a similar partitioning might have occurred among the ruminants.

            • I have no idea why you consider your arguments for common descent so compelling. The only way I could find them so is to choose to exclude other hypotheses.

              I am well aware of the PNAS article on wall lizards. I wrote a response to it at http://www.answersingenesis.org/articles/aid/v3/n1/life-designed-to-adapt. I do not see that this type of evidence distinguishes between the creation and evolutionary models.

              I am aware that epigenetic factors (including diet) can also affect development. Really cool pics can be found at http://www.das.psu.edu/research-extension/dairy/nutrition/calves/rumen. (This probably has nothing to do with our conversation, but I found this fascinating in vet school and you brought up stomach development.)

              Your questions about similarities make no sense to me. I am a vet. I thank God that he created creatures with similarities. Veterinary medicine is challenging enough; without the similarities it would be impossible. Many medical studies and advances would be impossible without the similarities. Understanding the world around us would be impossible if we didn’t have patterns that repeat. I guess part of the problem is that while I consider our nested hierarchies useful in taxonomy, I don’t see them as that neat. (Where creatures are classified in the scheme is constantly changing.) I see no reason to believe the distinguishing features between a ruminant stomach and a camelid stomach is transversible while maintaining viability. (I am not even sure if all ruminants are related. It is just that there is lots of overlap for many characteristics within the group while they retain a number of very distinctive features relative to other suborders.)

              • Thanks again for your input, Jean. I guess the reason why I find the theory of evolution so compelling is because it explains why we see what we do in nature today. Why are species different? Because natural selection acts on population variation to select against those individuals poorly adapted to their environments. Different environments and different selection pressures yield different species over time. Why do all species retain common traits in spite of their differences? Because those similarities have been inherited from a common ancestor, the same way my sister and I have blue eyes because my parents have blue eyes. This pattern of similarities and differences forms a nested hierarchy that only descent with modification predicts.
                I like Paul and Todd’s blogs because they’ve taken it upon themselves to actually come up with some evidence for the YEC scenario, rather than simply bash evolution all the time (indeed, they even concede there is some evidence FOR evolution). I’ve been eagerly reading their blogs for the last few months with the hope that they might be able to account for the nested hierarchy of life that I find so convincingly demonstrates evolution, but alas, I haven’t found such an explanation. I’ve seen people stress the importance of discontinuities between species (as you have), but again, this doesn’t account for their similarities. The only explanation I’ve heard for why so many different species retain so many similarities despite their differences is because “God made them that way”, which to me is about as useful an answer as “the sky is blue because God made it that way.” I’m a Christian, too, so I also believe God made life to be what it is. But I also want to know why and how He did it. I’m sorry that I haven’t found the answers from creation science more compelling.

  8. Does anyone out there have any idea how we can keep comments and replies together (and chronological) within a thread? More than one round of comments and replies and WordPress seems to mess the order up. It’s most frustrating, hence my less-than-ideal “Notes” appended to posts to make it more obvious who is responding to whom.

    • Hi Paul,

      It might be the “Enable threaded (nested) comments” option in Settings -> Discussion on the WordPress dashboard (if it’s the same as on my blog). Threading/nesting in comments never seems to work very well, as some people reply to specific messages and others simply add a comment to the end of the thread.

      • Hi Anthony, actually I think you’re right. I’ve now enabled threaded (nested) comments up to 10 levels deep (the maximum allowed) and that seems to have solved the problem.

    • I wish I knew how to order the comments, too, Paul. I reply to specific comments by hitting the appropriate reply button to the right of the comment, but it seems my reply appears randomly on the page.

      BTW, I really enjoy your blog, Paul. Between you and Todd, it’s refreshing to see an attempt being made at developing a positive creation model (rather than simply denying the evidence for evolution).

      • Thanks, Jordan. I’m glad that you like what we’re doing.

  9. From my experience in reading academic work it seems to me that all theories (in most disciplines) run into the problem of circularity at some point. We all fall pray to our most foundational assumptions at some point.


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