• Darwin’s Doubt – Chapter 2 – Part 3

    We continue with the section titled “The Bestiary”.  I broke this section up into several posts because Meyer covers a lot of ground in the typical Gish Gallop fashion.  Baldly stating ideas and concepts as if they are truth with no references or, if he does use references, they don’t agree with what he says.  The part I’m discussing now begins on page 31.

    Meyer says:

    The term “Cambrian explosion” was to become common coin, because Walcott’s site suggested the geologically abrupt appearance of a menagerie of animals as various as any found in the gaudiest science fiction. During this explosion of fauna, representatives of about twenty of the roughly twenty-six total phyla present in the known fossil record made their first appearance on earth (see Fig. 2.5).5

    The footnote (#5) refers to a paper by Douglas Erwin, who also seems to be a favorite of Meyer.  Why this is so, I’m not sure.  I haven’t gotten the full paper yet, but just reading the abstract, I see something that I wonder why Meyer doesn’t mention.

    The rapid diversification of animals in the early Cambrian is one of the most important evolutionary events in the history of life. Accordingly, this Cambrian ‘explosion’ has been the topic of extensive research: a multitude of contentious environmental, genetic, and ecological explanations have been proposed as primary causes or catalysts of this biological revolution. We present a new compilation of the patterns of fossil diversification in combination with new molecular clock results and comparative developmental data, and information on early ecological feeding strategies. These data demonstrate a macroevolutionary lag between the diversification of major metazoan clades and the establishment of their developmental toolkits in the Cryogenian, and their later ecological success in the Ediacaran and Cambrian. Focusing upon first fossil occurrences of the higher Linnean taxonomic rankings of phyla, classes and orders captures the origination pattern of major developmental innovation; the appearance of fossil phyla and classes is mirrored by new divergence time estimates for major clades and crown-groups, indicating robust, mutually-reinforcing fossil and molecular signals. We argue that the diversification of animals involved the establishment of new forms of developmental regulation, including novel controls on cellular differentiation, as well as innovations in networks of ecological interaction, all occurring within the context of permissive environmental conditions. The Cryogenian-Cambrian evolutionary lag illustrates the complex and potentially contingent nature of major evolutionary events, and highlights the importance of adopting a synthesis of developmental, ecological and environmental approaches to understanding the mechanisms driving an equally multifaceted Cambrian conundrum.

    In this paper, Erwin et. al. use four forms of data (fossil, molecular clock*, developmental, and ecological) to show a lag between the formation of the major clades and the diversification of those clades.  Erwin et. al. specifically states that the things that make these major clades (not phyla) developed in the Cryogenian.  The cryogenian is generally given to be a period of time ranging from roughly 850 to 635 million years ago.  That’s even before the Ediacaran (635-542 mya) and the Cambrian (542 – 485 mya).

    Meyer, honestly, why note these papers, but not present the data and analysis in them?

    Now, let’s talk about that figure a second.  I have some problems with the figure.  For example, Meyer shows that Molluscs appeared in the precambrian and rotifers appeared later in the eocene (between 47 – 34 mya).  My own research suggests that rotifers appeared much, much earlier.  That leaves me to question Meyer’s research here.

    Just as an example, Meyer references Swadling et. al. for his rotifer appearance.

    The Abstract:

    Early Holocene sediments from a continental Antarctic lake (Ace Lake, Vestfold Hills, East Antarctica) contained abundant fossil rotifers of the genus Notholca. The fossil is similar to specimens of Notholca sp. present in modern-day Ace Lake and other fresh and brackish lakes of the Vestfold Hills. Cyanobacteria and protists (chrysophyte cysts, dinoflagellate cysts, and rhizopod tests) were also recovered from the core samples. These sediments were deposited early in the freshwater phase of Ace Lake, soon after deglaciation of the area. The occurrence of this trophically diverse assemblage of organisms at an early stage in the evolution of the lake suggests either that they were part of an endemic Antarctic flora and fauna which pre-dated the last glacial maximum and survived in glacial refugia or that efficient intercontinental dispersal had occurred.

    The Holocene is our current geological period and extends back just over 11,000 years.  Yes, eleven THOUSAND years.  The research that Meyer cites is about some fossil rotifers from less than 11,000 years ago.

    Even if a date of earliest appearance of rotifers is mentioned in this article (another one I can’t find for free on-line) this isn’t a primary article.  This article isn’t about the earliest appearance of rotifers, it’s about modern rotifers.

    This is exceedingly sloppy research.  If I tried this (or got a paper like this), I’d be failing (or failing someone else’s work).

    In other words, now, we cannot trust a single thing in this chart.  It’s useless to us as any kind of reference, until we check out every single item on the chart.  If there is interest from my readers, I will attempt to do that.

    But that’s not even the most horrible thing about the diagram.  No, that’s in the description of it, where Meyer let’s loose this howler.

    According to Darwinian theory, differences in biological form should increase gradually, steadily increasing the number of distinct body plans and phyla, over time.

    NO. NO. NO. NO. NO.

    First, I’d like to see a citation for that claim.  This is a typical strawman attack against evolution here.  First, one says something that sounds reasonable (but it wrong), claiming that it’s what a particular idea predicts.  Then proceeds to show that idea is wrong.

    Having cited Gould so much, I’m surprised that Meyer doesn’t mention anything about the concept of Punctuated Equilibria.

    Punctuated equilibrium (also called punctuated equilibria) is a theory in evolutionary biology which proposes that most species will exhibit little net evolutionary change for most of their geological history, remaining in an extended state called stasis. When significant evolutionary change occurs, the theory proposes that it is generally restricted to rare and rapid (on a geologic time scale) events of branching speciation calledcladogenesis. Cladogenesis is the process by which a species splits into two distinct species, rather than one species gradually transforming into another.[1] (from Wikipedia)

    Darwinian Theory does not say that there should be a steady increase in distinct body plans.  I’ve read a lot of evolution material and I’ve never seen that stated anywhere.  Certainly not in the modern literature.

    As I explained here, phyla are arbitrary designations for groups of organisms.  That’s why most modern evolutionary biologists use the concept of clades which are based on morphological or molecular data.

    Meyer and other creationists may THINK that we should have a particular pattern of phyla increasing or decreasing, but they are the only ones that seem to.  Remember that every grouping beyond species (and some species) are just arbitrary groupings that may or may not make sense.  They can even (gasp) change.

    So, on page 31 and 32 Meyer does some sloppy research and makes a fundamental mistake about what evolution actually is.

    We’ll continue on with this section in the next installment.

    The rest of the series.

    ______________________________
    * Which we will get to in a later chapter.

     

    Category: Uncategorized

    Article by: Smilodon's Retreat

    • The footnote (#5) refers to a paper by Douglas Erwin, who also seems to be a favorite of Meyer. Why this is so, I’m not sure. I haven’t gotten the full paper yet …

      Look in your email box. It turns out the paper is available free with a simple registration.

    • Paul King

      Anyone who understands how evolution produces a nested tree of traits would know that most basic divisions would appear early. And that’s true even for Linnaean classification (although its more true for cladistic taxonomy – but I’ll stick to my understanding of Linnaean methods here)

      The traits that define a species as distinct from other species in it’s genus must have appeared as part of the process that made it a distinct species and not before.

      Before it became a distinct species this population must have already had the traits that define it’s genus. So the genus must appear before the species.

      And so on down the taxonomic tree.

      Linnaeus based his taxonomy on modern life, not on fossils that hadn’t been found in his lifetime (obviously!). And it is the divisions in modern life that control the classification of those fossils.

      Classifying two fossils as belonging to different phyla doesn’t mean that they have to be very different,as Meyer assumes. It just means that they have to have the distinctive traits of those phyla – which will be the earliest traits that each phylum developed.

      So Darwinian evolution predicts that the phyla will be established relatively early. And anyone writing a book about evolution and the origins of the phyla ought to know that much,

      • Christine Janis

        I was thinking of writing some sort of analogy/parody to the phyla issue. Four blokes of Irish descent in a pub in New York, with great stories about how they’re the descendents of four great Irish clans, that gave rise to the thousands of Irish who now live in New York. So they get to travel in a time machine back to the 18th century, to see the great giants from who they descended, and they find four blokes in a pub just like themselves.

        Perhaps Mr. Smilodon could work this into a cartoon.

        • SmilodonsRetreat

          That’s awesome.

          • Christine Janis

            Somehow I think it needs to be a movie with Simon Pegg and Nick Frost

            • Christine Janis

              Actually, and perhaps more to the point — I was at grad school with Russ Lande and Jerry Coyne (among others). Talk about the inception of phyla ——

      • Søren Kongstad

        Yeah – I’ve discussed with creationists who ask why we don’t see new phylas arise in modern times. And they were actual PhDs in fields relevant to biology!

        It’s kinda like asking why no one is born a great-great-great grand parent.

    • Joshua Hedlund

      Meyer has a whole chapter on punctuated equilibrium later in the book, though I didn’t find it very relevant to his overall points.

      • Buho

        Part 1 of the book is about showing that the missing fossils in the fossil record isn’t an illusion but real (the fossils being looked for never existed). Chapter 7, “Punk Eek!”, the last chapter in Part 1, is a good capstone to all that has been discussed prior: Gould pretty much agrees with chapters 1-6, and then proposes a solution to that. As Meyer shows in chapter 7, Gould himself backed away from this proposal later in life, so Meyer uses Gould again to refute Gould, concluding Part 1 with the thesis of Part 1: that all the evidence suggests the creatures Darwin wanted never existed in the first place.

        But that’s for chapter 7.

        • Paul King

          I’d be very surprised if Gould ever proposed Punc Eq as an explanation for the Cambrian “Explosion”. It simply doesn’t fit. It seems more likely that Meyer is relying on the Creationist idea that Punc Eq was proposed as an explanation for “missing fossils” without understanding it at all.

    • Ted Lawry

      Doing Meyer’s job for him (always necessary with creationists) I think what he is thinking of is the evolution of mammals from reptiles. The first proto-mammals were synapsid reptiles, they were basically no more different from diapsids than diapsids are from anapsids. Synapsids had the famous zygomatic arch, which now is a mammalian signature trait, but few other mammalian traits. Other mammalian features (one bone in lower jaw, dentary/squamosal jaw joint, coronid process, three bomes in middel ear, secondary palate) came later and developed in stages. That took about 100 MY (305 MYA to 210 MYA), culminating in Morganucodon, generally recognized as the First Mammal because it was the first known species to have a fully functioning dentary/squamosal jaw joint. It had all the other basic mammalian features too, the dentary/squamosal being the last feature to appear. In fact Morganucodon had TWO jaw joints, the dentary/squamosal side by side with the old reptilian articular/quadrate jaw joint. (How intermediate!)

      So Morganucon was the first mammal and had the defining characteristics of the mammalian class, and the later history of mammals produced many mammalian orders, families, i.e “top-down” evolution. But that was POST Morganucodon. The PRE Morganucodon period was very much “bottom-up” evolution in which the proto-mammals gradually diverged from the reptiles by gaining mammalian characteristics. To give Meyer his due, I think his point is that for Cambrian phyla, the equivalent of the pre-Morganucodon stage is missing. Considering the state of the fossil record back then, I don’t think that is a serious problem for evolution, but it is still true that evolution requires a bottom-up stage. Natura non facit saltum, and all that. Meyer makes it seem like the fossil pattern is worse than it really is, i.e. he says that the fossils are backwards, which sounds much more impressive than just saying the early stages are missing.

    • James Downard

      I am adding these additional postings of yours to my #TIP http://www.tortucan.wordpress.com anticreationism resource. As for Meyer’s treatment of Punctuated Equilibrium, he devoted a chapter to it but it is actually just the longest of the “hit & run” coverage I discuss in TIP 1.3 (Meyer makes 2 bonehead mistakes along the way, on allopatric speciation & P-E’s supposed decline)