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