Uncommon Descent Serving The Intelligent Design Community

Another rabbit jumps the hat: 419 mya JAWED fish

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Remember we were discussing how current Darwinian evolution theory would not be challenged even if a modern rabbit were found back in the 550 mya Cambrian era (and Darwin followers in the combox appeared to agree).

Hippety hop. A 419 mya jawed vertebrate.

The ancestors of modern jawed vertebrates are commonly portrayed as fishes with a shark-like appearance. But a stunning fossil discovery from China puts a new face on the original jawed vertebrate. [US$18 paywall]

National Geographic News reports*,

“Entelognathus primordialis is one of the earliest, and certainly the most primitive, fossil fish that has the same jawbones as modern bony fishes and land vertebrates including ourselves,” said study co-author Min Zhu of the Chinese Academy of Sciences in Beijing.

But in the new fossil, found in China, has a distinctive three-bone system still used by chewing vertebrates today: a lower jawbone called the dentary and two upper jaw bones called the premaxilla (holding the front teeth) and the maxilla (holding the canine and cheek teeth).

“The exciting thing about this fossil is that when you look at the top of it, it looks like a placoderm, but when you look at the side of the fish and the structure of the jaw, it doesn’t look like any placoderm that we know of,” Friedman said.

“This tends to suggest the exciting possibility that these jawbones evolved way deep down in the lineage, so these features we used to hold as being unique to bony fishes may not be so unique.”

In other words, less evolution and more stasis.

The fish seems to lave lived at the end of the Silurian period, 443 mya to 417 mya.

*Reports it, that is, under the curious title,

”Fish Fossil Has Oldest Known Face, May Influence Evolution“

Influence evolution? Baby, if they found it back then, it IS evolution. Unless, of course, you mean Evolution, the Religion. In other words, the fish may shake up your dogmatics a bit, but whose problem is that, besides yours, at this point?

Fish guy, yer gettin’ ta be a rabbit with me.

Comments
Darwin's Doubt #1 in Kindle Store > Kindle eBooks > Nonfiction > Science > Biological Sciences > Paleontology #2 in Books > Christian Books & Bibles > Theology > Creationism #2 in Kindle Store > Kindle eBooks > Nonfiction > Religion & Spirituality > Religious Studies > Science & Religion And we know its only in the Religion section because some angry rabid atheist complained about it, and who likes rabid frothing from the mouth atheists? Nobody that's why the world tippy toes around them.....Andre
October 1, 2013
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Dr Liddle Id Dr Meyer's book is not a good paleontology book or even a non-science book why is it the the number 1 seller in the biological sciences, paleontology section? http://www.amazon.com/gp/bestsellers/digital-text/158652011/ref=pd_zg_hrsr_kstore_1_6_last Not a true Scotsman you say?Andre
October 1, 2013
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If EL taxonomy is true, titaalik is an anphibian.Chesterton
October 1, 2013
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KF, this is incorrect. There is no such subtext as you imply. My point is simply the point I made: that Meyer's book is not a scientific book, albeit one dealing with "scientific topics", because Meyer' lacks the knowledge and understanding of palaeontology to write a scientific books. I do not trash Meyer's logic because he writes for a religious imprint. I have written for a religious imprint myself. I trash his logic because his logic is fallacious. I note that such logic would not pass muster in a scientific imprint, and that it is not, in fact, so published. tbh, KF, I'd say you are the one "well-poisoning" here - you appear to be trying to discredit my argument by casting aspersions on my own moral integrity. I'm not going to upbraid you for this, I merely point it out. What I will do, however, is suggest that you have got yourself into a state whereby you suspect nefarious motives in any person who writes, or "enables" the writing of, views with which you disagree, and that this level of paranoia is not good for you. I'd like to suggest that you take a step back, and remember that we are all human citizens of this world, trying to make sense of it as best we can, siblings under the skin, and, presumably in your view, all children of God. We may disagree profoundly about much, and have very different fears about what views from which we dissent imply for the good of us all, but most of us, on both sides, are honest, however misguided we can think those on the "other" side are. Please take time to consider this, and perhaps reflect that your habit of assuming the worst in me, and in others who share my views, and of seeing ominous subtexts in posts that are simply not there, is just that - a habit, and one it may be healthy for you to try to shed. I mean this in all sincerity, and wish you well, aware that you have far more serious things to worry about right now than that "someone is wrong on the internet". As always, peace. LizzieElizabeth B Liddle
October 1, 2013
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PPS: It is also a serious sign of the lockhold on institutional power in our times that a book obviously dealing with scientific topics, DD, and on a science-empirical reasoning base, evidently has to seek partnership with a self-help and spirituality imprint in order to see the light of day. EL's attempt to deride and trash Meyer's logic by alluding to this is below the belt. Again. And, it tellingly echos DH's ill tempered and equally ill informed sneer about the inevitable irrationality of "faith" exposed and rebutted here. The obvious subtext of EL's remarks above is that Meyer is a ringleader of the projected totalitarian right wing religious conspiracy to treasonously subvert our civilisation, a primary enemy of humanity. This grotesque conspiracy narrative is a slander, and it is patently poisoning and polarising the atmosphere. EL's enabling behaviour is again exposed. KFkairosfocus
October 1, 2013
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PS: I should add this on the logic of increasing diversification on the Darwinist model: CV + DRS --> IDWUM CV -- chance variation, DRS -- differential reproductive success [aka natural selection or selection of favoured races], IDWUM -- incremental descent with unlimited modification Plainly, an initial pop is expected to increasingly diversify, giving rise to increasingly disparate clusters with common ancestral roots. So, the emergence of biodiversity SHOULD be bottom-up, and consequently we should see phyla emerging later. However, the transition to multicellularity with tissues, organs and integrated systems emerging through development of an embyo or the comparable, would cut across kingdoms and would come before that. The point properly at stake is therefore that throughout the world of life, we do not find the IDWUM pattern in fossils or living forms. Instead we find among animals, the Cambrian explosion of forms where from the outset on the conventional timeline, we are already seeing diversity at phylum and sub-phylum levels, apparently up to and including the most "advanced," chordata. Indeed, it seems fish -- jawless, like modern lampreys -- are there in the Cambrian fossils. And as the OP mentions, we now have jawed fish dated at 419 MYA on the timeline. The point to be answered is, to ground that claimed transition to dozens of phyla and subphyla on observations, not inferences and ideological a prioris. From LUCA on, at minimum. And, it is quite reasonable in that context to require empirical demonstration of blind watchmaker chance and necessity showing capacity to originate the sort of complex integrated functionally specific organisation and associated information that are required. Absent such demonstrated capacity to originate FSCO/I the inductive logic on what we routinely see remains unanswered: FSCO/I is reliably produced by design. Where the linked needle in haystack blind search challenge shows why that is utterly unlikely ever to be met. Absent an observational basis, what we are dealing with on these trees of life icons and taxonomies riddled with circular reasoning is ideology hanging confirmation bias illustrations on itself, not proper science.kairosfocus
October 1, 2013
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F/N: NWE, discussing taxonomy, helps us understand a lot of what is going on behind the scenes:
An authoritative definition of taxonomy (as used in biology) is offered by Systematics Agenda 2000: Charting the Biosphere (SA2000), a global initiative to find, describe, and classify the world's species. Launched by the American Society of Plant Taxonomists, the Society of Systematic Biologists, and the Willi Hennig Society, and in cooperation with the Association of Systematic Collections, SA2000 defines taxonomy as "the science of discovering, describing, and classifying species or groups of species." The Select Committee on Science and Technology of the United Kingdom Parliament also offers an official definition for taxonomy: "We use taxonomy to refer to the activities of naming and classifying organisms, as well as producing publications detailing all known members of a particular group of living things." The term "systematics" (or "systematic biology") is sometimes used interchangeably with the term taxonomy. The words have a similar history and similar meanings: Over time these have been used as synonyms, as overlapping, or as completely complementary. In general, however, the term systematics includes an aspect of phylogenetic analysis (the study of evolutionary relatedness among various groups of organisms). That is, it deals not only with discovering, describing, naming, and classifying living things, but also with investigating the evolutionary relationship between taxa (a taxonomic group of any rank, such as sub-species, species, family, genus, and so on), especially at the higher levels. Thus, according to this perspective, systematics not only includes the traditional activities of taxonomy, but also the investigation of evolutionary relationships, variation, speciation, and so forth. However, there remain disagreements on the technical differences between the two terms—taxonomy and systematics—and they are often used interchangeably . . . . Some major developments in the system of taxonomy since Linnaeus were the development of different ranks for organisms and codes for nomenclature (see Domain and Kingdom systems, and Universal Codes above), and the inclusion of Darwinian concepts in taxonomy. According to Hull (1988), "in its heyday, biological systematics was the queen of the sciences, rivaling physics." Lindroth (1983) referenced it as the "most lovable of the sciences." But at the time of Darwin, taxonomy was not held in such high regard as it was earlier. It gained new prominence with the publication of Darwin's The Origin of Species, and particularly since the Modern Synthesis. Since then, although there have been, and continue to be, debates in the scientific community over the usefulness of phylogeny in biological classification, it is generally accepted by taxonomists today that classification of organisms should reflect or represent phylogeny, via the Darwinian principle of common descent. Taxonomy remains a dynamic science, with developing trends, diversity of opinions, and clashing doctrines. Two of these competing groups that formed in the 1950s and 1960s were the pheneticists and cladists. Begun in the 1950s, the pheneticists prioritized quantitative or numerical analysis and the recognition of similar characteristics among organisms over the alternative of speculating about process and making classifications based on evolutionary descent or phylogeny. Cladistic taxonomy or cladism groups organisms by evolutionary relationships, and arranges taxa in an evolutionary tree. Most modern systems of biological classification are based on cladistic analysis. Cladistics is the most prominent of several taxonomic systems, which also include approaches that tend to rely on key characters (such as the traditional approach of evolutionary systematics, as advocated by G. G. Simpson and E. Mayr). Willi Hennig (1913-1976) is widely regarded as the founder of cladistics.
In blunt words, taxonomy too plainly represents a case where objective science based on evaluating and explaining the observed has been tainted with ideological question-begging. So, the now sadly usual circularities emerge in what is presented to students and the public as "fact." Predictably, this comes out in the similar Wiki article:
Phylogenetics and cladistics Today, traditional rank-based biological classifications persist in a structure largely unchanged since the 1700s; however, how the relationships of these taxa are investigated has changed drastically in recent decades. It is now common for biologists to devise a classification based on the results of phylogenetic analysis using DNA sequence data, and taxa are typically required to be clades. Although phylogenetics itself is fundamental to modern-day systematics, its use for the description of new taxa, and for their placement within a classification scheme, is not required. Phenetics In phenetics, also known as taximetrics, organisms are classified based on overall similarity, regardless of their phylogeny or evolutionary relationships. It results in a measure of evolutionary "distance" between taxa. Phenetic methods have become relatively rare in modern times, largely superseded by cladistic analyses, as phenetic methods do not distinguish plesiomorphic from apomorphic traits. However, certain phenetic methods, such as neighbor joining, have found their way into cladistics, as a reasonable approximation of phylogeny when more advanced methods (such as Bayesian inference) are too computationally expensive.
In this context, the whole project of constructing a tree of life intersecting with higher level taxa becomes ideologically loaded and riddled with circular reasoning. For instance, Wiki glides over the hard fact that multiple molecular trees stand in mutual contradiction and the further fact that molecular clock reconstructions are patently unreliable. Similarly, there is the obvious question that classification should be based on observed populations and reasonable clustering of key similarities and differences, whether living or fossil. Once such is imposed, we will reliably see that hypothetical single root species of high level taxa are as a rule just that, guesses not observations. So, they do not properly belong in a classification based on observed populations with equally observed characteristics. If we cut off those hypothesised roots, we obviously will be collecting clusters of branches on the hypothesised tree which will include many hypothetical ancestral species. Also, such clusters will have branches leading away as well as those coming in. This explains the diagrams Meyer made, criticisms on details and a typo or two notwithstanding. The attempt to seize on diagrams to distract from the problem of sudden radical diversity of forms in the Cambrian fossils, plainly fails. But it will predictably be used henceforth as a distractor. This also sets up the context in which WD400's dodge on the challenge to ground the tree for a phylum in a specific pattern of observations tracing to the hypothetical latest unicellular common ancestor, shows its significance. Between mutually contradictory molecular trees and systematic gaps in terms of observed populations, we have good reason to question the circularities seen above. The challenge to justify origin of body plans on incremental evolutionary forces, backed up by adequate observations, remains unanswered. Apart from a priori ideologically loaded and question begging impositions. Where, not even the apparently innocent and objective exercise of constructing a classification scheme for life forms escapes that ideological question-begging. Where also,you are ignorant, stupid, insane or wicked is not good enough to answer to that challenge. KFkairosfocus
October 1, 2013
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Here is the paper that created the curiosity in me about the perfection of the food chain and Eco-systems. http://www.cell.com/trends/ecology-evolution/abstract/S0169-5347%2802%2902455-2Andre
October 1, 2013
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I guess this is slightly off topic, The presence of a working food chain from the beginning is an issue for Darwinian evolution...... The whole thing is way too convenient, to have been caused by some hap hazard random process. The balance is precise and truthfully all systems (including the food chain) left to their own devices in our observed experience ends up in chaos.Andre
October 1, 2013
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Q: Is the quote in #138 from, “The Changing Role of the Embryo in Evolutionary Thought”? A: Yes, it is. Finishing up the final chapter.Mung
October 1, 2013
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Dr. Liddle, I meant to say- this is not the case with the fossil record leading up to the Cambrian assemblage.littlejohn
September 30, 2013
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Mung, Is the quote in #138 from, "The Changing Role of the Embryo in Evolutionary Thought"? Thanks!littlejohn
September 30, 2013
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Dr. Liddle, I do not see how the example of the electron relates. We can detect and measure the effects and characteristics of an electron, however, this is not the case with the fossil record. As I previously posted, the UCA is certainly a plausible theory, but not fact. IMO, the exclusion and censorship of alternatives just because we do not prefer them is unscientific, and unacceptable.littlejohn
September 30, 2013
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littlejohn
I do not have a problem with models that are constructed/supported by direct observation (tangible evidence).
Firstly, fossils are directly observed. Second, all models have to be supported by observation. Many observations are not direct. Nobody has ever seen an electron, for instance.Elizabeth B Liddle
September 30, 2013
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He uses the phrase "Darwinian theory". I used the phrase "Common Descent" because Darwin had two theories: common descent, and the mechanism of adaptive evolution (descent with modification plus natural selection). The chapter (and indeed the book) concerns the case for common descent, rather than the case for Darwinian evolutionary mechanisms. And seeing that at least some ID proponents accept common descent but not Darwinian mechanisms, I wanted to make that clear.Elizabeth B Liddle
September 30, 2013
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STRAW MAN ALERT!!! Elizabeth Liddle:
Yet it contaminates his entire argument about what he says is expected “under Common Descent”. What is expected under Common Descent...
I just re-read the entirety of chapter 2. Nowhere in it does Meyer employ the phrase "under Common Descent." So where on earth did it come from, Elizabeth? Some other chapter perhaps?Mung
September 30, 2013
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"...no law of nature can apply to such entities as supraspecific taxa. Taxonomy is mere record keeping, and it involves neither laws nor causal explanations." - Amundson, 2005.Mung
September 30, 2013
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Dr. Liddle, I do not have a problem with models that are constructed/supported by direct observation (tangible evidence).littlejohn
September 30, 2013
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F/N 2: 3 bn yrs of inferred evo cannot be presented with diagrams in a comment box [and UD locks out comment diagrams -- at least so far as I gather], but a simple description and link or links can be placed in that comment. Or even, a 6,000 word or so summary with onward links. Why, it is even possible to link to a whole book, given the magic of PDF. (try, incoherence of the philosophers in English, here, which is also presented as html as a book here.) The attempted dismissal at 118 is little more than a disguised, discourteous admission that the required actually observed evidence does not exist. Optimus' point in 122 that we have a lot of question begging going on is plainly on target. KFkairosfocus
September 30, 2013
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F/N: I see an invitation to go to the same TSZ that continues to host slander, such as this. Invitation refused, for cause. KFkairosfocus
September 30, 2013
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Onlookers: do you notice the question-begging at work, unsurprising in the thought of a day in which science and its methods are often improperly question-beggingly redefined. Also, observe how we see no response to the challenge to provide observational warrant for the origin of a phylum from a unicellular common ancestor. Not, inference, imagination and assumptions or assertions, observation. In that context, whether or not it is currently in intellectual fashion to do so, the only objective basis for biological classification of life forms is based on observed populations, whether living or fossil. I freely argue in this light that the commonly encountered root node species that gives a one-point entry into a group of organisms is, as a rule, inferred not observed. Those who wish to dismiss me on the subject can simply provide an observationally warranted tree that shows per actually observed specimens of species [and not loaded inferences on ancestry through various assumptions boiling down to homology implies ancestry], the origin of at least one phylum from a common unicellular organism, or as close as we get to that. KFkairosfocus
September 30, 2013
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Optimus
I took the trouble to reread your post over at TSZ and I came away with the impression that you were terribly uncharitable and made no genuine effort to set aside your considerable prejudices so as to understand the point being made.
Yes, well, I'm not feeling very charitable towards Meyer, who frankly has no excuse for this book. He's a smart guy, and he knows enough about science to know that you have to know a heck of a lot more about a science to be able to write a book overturning it. And I strongly suspect that he knows that his book is a logical mess, but thinks it serves some higher purpose anyway. After all, he has published under a religious imprint, not a science one. So in that sense you are correct. However, you are not correct that I made no attempt to understand the point being made. I always attempt to understand points being made, and made considerable effort here. I think he's wrong. That is not a matter of "prejudice" it is a matter of, well, considering, on good grounds, that he is wrong.
As I am not a paleontologist, though, my criticism of your post will attempt to be modest. I should add that I didn’t bother to wade through all the preceding posts with any diligence, so I may inadvertently make critiques that have already been posted. My apologies if that is the case…
No problem. I am not a palaeontologist either.
Well, of course it does, Dr Meyer! You have just, in Chapter 2 of your fat book made an absolutely fundamental error of understanding of the entire principle of phylogenetics and taxonomy. No, of course you wouldn’t expect phyla to follow “lower-level diversification on those basic themes”. How could it possibly? And how could you possibly so fundamentally misunderstand the entire point of Darwin’s tree and its relationship to the nested hierarchies observe by Linnaeus?
What a tiresome rant – you display all the characteristic restraint of an over-caffeinated, arrogant high school sophomore. Deficiencies of your prose aside, the principal shortcoming of your post is that you assume that the terminological difference between you and Meyer is purely a function of his stupidity.
No, I do not. He isn't stupid. I think it's worse than that.
In your post you describe phyla in this manner:
It’s because what we call phyla are groups of organisms with an early common ancestor, whose later descendents have evolved to form a group that has a large morphological distance from contemporary populations who descended from a different early common ancestor.
The description you present clearly assumes as a starting point the evolutionary relatedness of organisms. So it’s really a loaded definition, and it wouldn’t make any sense for Meyer, writing a book critical of several aspects of contemporary evolutionary theory, to define phyla or any other level of classification in a manner that assumes the truth of evolutionary theory!
Meyer describes what Common Descent predicts, wrongly. Clearly, if he is attempting to describe not what he believes, but what he thinks the people he disagrees with believe, then he needs to get that right.
Instead it seems that he employs a conception of phyla that uses morphology as its guide (the phenetic definition according to infallible Wikipedia) instead of putative evolutionary relatedness. On page 31 of Darwin’s Doubt he writes:
The term “phyla” (singular: “phylum”) refers to divisions in the biological classification system. The phyla constitute the highest (or widest) categories of biological classification in the animal kingdom, with each exhibiting a unique architecture, organizational blueprint, or structural body plan.
(Emphasis mine) So right in the beginning of the text, before any of the maligned diagrams, he makes it perfectly clear what he means by phyla.
Yes. And the point about that system is that it works because the features of organisms fall into a nested hierarchy, which demands some kind of explanation. One explanation is Common Descent. If Common Descent is the answer, then we would expect that the features common to all members of a taxon would be present in a common ancestor, but that features shared only by a subset ("derived" characters) would not be. Hence the term "primitive" characters for those features postulated to be possessed by the common ancestor. So Common Descent makes very clear predictions about the fossil record - the further back we go in time (dateable from the strata in which the fossils are found) the more we are likely to find fossils in which only the postulated "primitive" characters are found. And of course we do, which is why Common Descent is so well supported as an explanation for the nested hierarchy - the nesting is not only found in the features of extant organisms, but the prediction made by Common Descent as the explanation is supported by the time line of the fossils.
He also explicitly acknowledges that there are different ways classifying organisms – page 31 again:
Throughout the book I will use these conventional categories of classification, as do most Cambrian paleontologists. Nevertheless, I am aware the some paleontologists and systematists (experts in classification) today prefer “phylogenetic classification,” a method that often uses a “rank-free” classification shceme. Advocates of modern phylogenetic classification argue that the traditional classification system lacks objective criteria by which to decide whether a certain group of organisms should be assigned a particular rank of, for example, phylum or class or order. Proponents of rank-free classification attempt to eliminate subjectivity in classification (and ranking) by grouping together animals that are thought, based on studies of similar molecules in different groups, to share a common ancestor. (Emphasis mine – internal citations removed)
Grasping the distinction between the phylogenetic view and the phenetic view (and understanding that Meyer employs the latter view) removes the difficulty that you feel attends the several diagrams in the book.
No, it does not. If he were simply arguing that the "rank-free" approach (in other words the entire approach of phylogenetics) was misguided then he might have the makings of an interesting book. But he doesn't. He just relegates the point to detail about what "convention" he is using. Yet it contaminates his entire argument about what he says is expected "under Common Descent". What is expected under Common Descent is a blurring of categories at the root of each clade, with early organisms that possibly belong to phylum A or phylum B being sufficiently similar that it is hard to say to which lineage (or category) they belong. In other words, the "morphological distance" between members of phyla at the root of those phyla will be close. And so his argument that "disparity" as a measure of "morphological distance" is also a feature of the organisms in different phyla is undermined. It is only true if we refuse to categorise any organism as a member of a phylum until long after the phylum is postulated to have begun. But in that case, it renders his prediction "under Common Descent" wrong. As I keep saying, he can't have it both ways.
Really a careful reading of the text, combined with a careful examination of the diagrams makes their point quite clear. You write (in reference to 2.11):
I’ve amended the drawings in the book as below, and, instead of labeling the trees by what a contemporary phylogeneticists[sic] might have called them, I’ve called each tree a phylum, and I’ve drawn round the organisms that constitute various subdivisions of phyla in colours from orange to green to represent successive branchings. Rather than the little bunch of twigs marked “families” by Meyer, I’ve indicated the entire clade for each subdivision, or tried to.
As is evident in your caption, you take the phylogenetic view, oblivious to the fact that Meyer is using classification in a morphologically-oriented fashion.
Obviously I do. But If we take Meyer's idiosyncratic implied view, then he gets the prediction of Common Descent wrong.
The second tree, marked genus #1, contains organisms similar enough in morphology that one might (on said grounds) group them as being in a single genus. Time passes and we arrive at tree three which contains genera #1-3. More evolution has taken place, and the extant organisms no longer fit into a single genus, necessitating the need for two more. By the time we reach tree number four there are four genera, #1&2 of which can be grouped as a family, #3&4 comprised in another family. As long as one bears in mind that these diagrams (and the book in general) utilize a morphological perspective (not a phylogenetic perspective) they are quite easy to understand (unless you read sloppily or have an axe to grind).
I have no axe to grind. As I say, a "contemporary palaeontologist" would regard the first little shrub as something like a genus with species. By the time the whole tree is there, a much later palaeontologist would look at that same little shrub at the bottom of the whole tree and call its branches phyla. It's not that the phyla emerge later, it's that once the rest of the branches are present that we require more taxonomic ranks to represent the depth of nesting. So under Common Descent, we expect phyla divisions to precede species divisions. But we also expect the morphological distance between phyla to be less at the root (no more than between two recent species) than at the tip. And that is what we observe. We only don't observe it if we use Meyer's arbitrary paraphyletic circles. But if we use his terminology, then we would phrase the Common Descent prediction differently - the prediction would still be identical, and still match observation.
In a sense your post (laden with suffocating condescension) is itself an excellent case study of the difficulty inherent in having a meaningful interaction with a viewpoint that challenges one’s own.
It may well be. The book made me rather angry, I confess. But I agree that it is difficult to have a meaningful interaction with someone whose base viewpoint is very different, as is evident in this thread.
While Meyer obviously has a point in mind to make, his use of terminology is much more neutral than is yours, which is clearly question-begging. So instead of reading the text carefully to find out why he uses the terms as he does, you simply upbraid him for being stupid and top it off with a snarky one-liner about not knowing the singular form of “phyla.” To your credit you corrected the error, but it nevertheless remains astonishing that you could make such a fuss over a typo (especially given that your OP is infested with them as a corpse is with maggots).
I didn't make a fuss over a typo. I tossed it off as a parenthesis on a one liner on an ETA, then corrected it. Mung has been doing the fussing.
And all this after stating that you are not qualified to judge factual errors. Simply disgraceful.
I am not qualified to judge factual errors regarding palaeontology. However, I am as qualified as anyone, including you, to judge whether the argument actually makes sense. Here is the problem as I see it as dispassionately and as clearly as I can make it: Meyer argues that under Common Descent we should see small morphological distances between lineages that become larger over time, as each lineage diversifies down separate lineages. Correct. He then argues that we don't see this. Wrong. He bases his assertion that we don't see it on the fact that "phyla" divisions, come before "lower taxa" such as "families" or "genera" in the fossil record. Correct. He then characterises phyla as groups separated by a "large morphological distance", and thus argues that because phyla came before genera, then large distances came before small, in contradiction to the expectation under Common Descent. And here is the problem: if we define phyla "phylogenetically" then there is no contradiction - phyla were morphologically close when they started, AND they started before genera. So the expectation under Common Descent (small morphological distances before larger) holds, AND phyla before genera holds. But, alternatively, we don't call something a phylum unless the morphological distance between phyla has become substantial, then the prediction under Common Descent still holds, because now, phyla don't appear before genera. So he is equivocating. He cites evidence, based on phylogenetic usage, that phyla appeared before genera, to contradict the "prediction" that small morphological distance appear before large, even though, under that usage, phyla will be similar near their root. But under "phenetic" usage, we can't identify phyla until there is a large morphological distance between them, in which case, they don't appear too early for the prediction under common descent. Bottom line: Common Descent predicts that small differences will precede diversification. This is what we observe in the fossil record. What we call things is irrelevant to the straightforward match between prediction and observation. What IS true, however, is that many lineages that start don't go anywhere, or go for a while then go extinct. So, as time goes on, early phyla (using phylogenetic terminology) will outnumber later phyla. So if we estimate "disparity" as "number of phyla" then disparity, by that definition, will decrease under Common Descent This is why it is so important to define terms clearly, and not equivocate between different meanings of the same terms. In my view, Darwin's Doubt is a masterpiece of equivocation, and I think Meyer is smart enough to know this. That is why I express my disapproval in my post - not because I am "prejudiced" against his case (it would be cool if true) but because I don't think he is being honest. I think the book is a piece of polemic disguised as reasonable argument, and the trick used is the oldest one in the book - equivocation with terms. But the diagrams are the giveaway. Anyway, I'd be delighted to continue this at the thread at TSZ, if anyone would like to come over. I think I'm done with this thread.Elizabeth B Liddle
September 30, 2013
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Mung
How the circles are drawn are completely irrelevant to the point Meyer is making, which is the expected trajectory of differentiation, with minor difference (diversity within taxa) coming before major differences (disparity).
No, it isn't "completely irrelevant to the point he is making". The drawings are used to illustrates the points he is making (i.e. they are not simply there to decorate the page - he actually draws attention to them to make his points and invites to compare them). The expected trajectory of differentiation under Common Descent, is indeed, minor differences in a pair of lineages that gradually move further and further apart. And that is what we observe. Trying to imply that something else is what we observe by misapply taxonomic labels doesn't make that go away. He is creating a problem where none exists.Elizabeth B Liddle
September 29, 2013
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Mung, there would be no "moral difference" and I was doing neither.Elizabeth B Liddle
September 29, 2013
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Mung, if you aren't confused then you are deeply confusing. If you were around at the time, say, the common ancestors of arthropods and velvet worms split you wouldn't say they were different phyla. However, taxa are lineages so those species are members of different phyla. A phylum (or any other higher level taxon) is only a "thing" in the sense that it's a natural lineage, the levels at which we draw the ranks is a purel human thing (species being the only exception, and the fundamental unit of biodiversity)wd400
September 29, 2013
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Good like finding someone supporting phenetics classification these days - it's mainly used as an insult now.wd400
September 29, 2013
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WD @ 125
All taxonomy is phylogenetic, and he’s trying to illustrate an explicitly phylogenetic story. That people are so keen to defend this is very strange.
http://en.wikipedia.org/wiki/Taxonomy_(biology)#Phylogenetics_and_cladistics Evidently notOptimus
September 29, 2013
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"Nothing cramp's one's causal powers like not existing." - Fodor and Piattelli-Palmarini
wd400:
The event that splits two phyla is speciation event, so indeed Elizabeth is right and you are confused.
An event has no effect on something that does not actually exist. Can we move on now?Mung
September 29, 2013
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wd400:
All taxonomy is phylogenetic
simply. false.
...he’s trying to illustrate an explicitly phylogenetic story.
Yes. The Darwinian story. It doesn't follow that all his diagrams are phylogenetic trees or cladograms, or even that any of them are phylogenetic trees or cladograms, or that any of them are even intended to be phylogenetic trees or cladograms, or whatever it is that you think they ought to be, a point which both you and Elizabeth have still failed to clarify. Was Fig. 2.11a intended by Darwin to be a phylogenetic tree or cladogram?Mung
September 29, 2013
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As is evident in your caption, you take the phylogenetic view, oblivious to the fact that Meyer is using classification in a morphologically-oriented fashion All taxonomy is phylogenetic, and he's trying to illustrate an explicitly phylogenetic story. That people are so keen to defend this is very strange.wd400
September 29, 2013
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