Microdissecting Meyer
The extensive, 6,000 word review of Meyer's recent 'peer-reviewed' Intelligent Design paper by Gishlick, Matzke, and Elsberry takes a broad look at all of the flaws in the work, and gives us the big picture view of why it is poor science that shouldn't have made it past any qualified reviewers. I'm going to take a much more narrow approach, and look at a single paragraph and show why it represents poor, biased scholarship. I'm motivated in part by a ridiculous critique from Joe Carter. One of the things he does (in his second point, if you bother to read it) is a practice creationist pseudoscientists are getting very good at, and that Meyer also practices in his paper: throwing a bunch of scientific references at the reader that, in Carter's case, the creationist has never read, or in Meyer's case, may have read but misrepresents. How many people would bother to check that these esoteric references are being reported accurately? How many of us who actually are comfortable with the scientific literature have the time to cross-check and report all of the misrepresentations being made?
I sure don't. That's why I'm just going to pick on one paragraph.
The general topic of the Meyer paper is the Cambrian explosion, which he calls "a paradigmatic example of the origin of biological form and information", and what he wants to assert is that we need "a new and specifically causal theory" which is, of course, Design…which is neither causal, nor specific, nor a theory, except in the vaguest senses of the words. Reading the introduction to the paper, where he brings up modern ideas in developmental genetics as examples of revolutionary stuff that is shaking up neo-Darwinism was very aggravating to me (Intelligent Design, I know developmental genetics well…and you, sir, are no developmental genetics), but I'll criticize something more central to the paper, Meyer's version of the Cambrian. Here's his short summary of the event:
The Cambrian explosion represents a remarkable jump in the specified complexity or "complex specified information" (CSI) of the biological world. For over three billion years, the biological realm included little more than bacteria and algae (Brocks et al. 1999). Then, beginning about 570--565 million years ago (mya), the first complex multicellular organisms appeared in the rock strata, including sponges, cnidarians, and the peculiar Ediacaran biota (Grotzinger et al. 1995). Forty million years later, the Cambrian explosion occurred (Bowring et al. 1993). The emergence of the Ediacaran biota (570 mya), and then to a much greater extent the Cambrian explosion (530 mya), represented steep climbs up the biological complexity gradient.
Notice the citations. The idea behind scientific citations is that they should be papers supporting the ideas being discussed, and are shortcuts for the author—instead of tediously enumerating all the evidence to support a claim, he points the reader to another source that documents it. There is a bit of trust involved; a scientific paper may easily throw 50 references at the reader, and it's a difficult chore to check them all. (This, by the way, is one reason peer-review is supposed to be done by individuals qualified in the field; they are likely to have already read many of the cited papers, are more or less familiar with their contents, and reviewing one paper doesn't necessarily involve scurrying to the library and reading 50 more papers to see if they were correctly represented.)
There are three citations in this paragraph. Let's see how well Meyer represents their contents, and to be generous, I'll start with one that he gets right.
Forty million years later, the Cambrian explosion occurred (Bowring et al. 1993).
Meyer tells us the relative timing of the Cambrian explosion, and he gets the dates right. The Bowring et al. paper is titled "Calibrating rates of early Cambrian evolution", and it's all about more precisely dating the events of the Cambrian period using uranium-lead zircon geochronology. Meyer is capable of reporting a single number correctly!
For over three billion years, the biological realm included little more than bacteria and algae (Brocks et al. 1999).
Uh-oh. This one is very misleading. Brocks et al. is a paper about molecular fossils: they analyzed trace materials in ancient rocks, looking for the chemical signatures characteristic of different domains of life. While it is talking about trace molecules left largely by bacteria, it makes no statement about the absence of other organisms, and explicitly states that the phylogenetic position of the eukaryotes responsible for the lipids they found is unclear. And in fact, one of the main points of the paper is to push back the timing of the origins of greater cellular complexity, which apparently is something Meyer would like to sweep under the carpet. Brocks says,
We conclude that the domain Eucarya first appeared before 2700 Ma and is at least 500 to 1000 My older than indicated by current paleontological data. This age should provide a new calibration point for molecular clocks and the universal tree of life.
The other citation in this paragraph is similarly used selectively, ignoring the bulk of the paper to support a minor point.
Then, beginning about 570--565 million years ago (mya), the first complex multicellular organisms appeared in the rock strata, including sponges, cnidarians, and the peculiar Ediacaran biota (Grotzinger et al. 1995).
Grotzinger et al. is an interesting work: it builds on the timeline of the Bowring paper to place known Precambrian and Cambrian fossils in better context. It doesn't deny that there was a diversification of body plans in the mid-Cambrian, but it takes a position that contradicts Meyer's:
Once held as the position in the rock record where the major invertebrate groups first appeared, the Precambrian-Cambrian boundary now serves more as a convenient reference point within an evolutionary continuum. Skeletalized organisms, including Cambrian-aspect shelly fossils, first appear below the boundary and then show strong diversification during the early Cambrian. Similarly, trace fossils also appear first in the Vendian, exhibit a progression to more complex geometries across the boundary, and then parallel the dramatic radiation displayed by body fossils.
Here's the concluding sentence of the paper:
Considered collectively, however, the most parsimonious interpretation of the available fossil and age data is that the early development of animals proceeded as a single, protracted evolutionary radiation, culminating in the Cambrian explosion.
It's saying something entirely different from what the Discovery Institute wants you to think of evolution and the Cambrian.
Now you might be able to see what a qualified reviewer would see when reading the Meyer paper. It's full of these peculiar disconnects from the reality of the scientific literature—he's constantly citing little fragments of papers while ignoring the bulk of the work. It's a more rarefied version of more typical creationist quote mining, made slightly more sophisticated and much more difficult to check, and designed to wow the rubes rather than persuade anyone knowledgeable in the subject.
Bowring SA, Grotzinger JP, Isachsen CE, Knoll AH, Pelechaty SM, Kolosov F (1993) Calibrating rates of early Cambrian evolution. Science 261:1293-1298.
Brocks, JJ, Logan GA, Buick R, Summons RE (1999) Archean molecular fossils and the early rise of eukaryotes. Science 285:1033-1036.
Grotzinger,JP, Bowring SA, Saylor BZ, Kaufman AJ (1995) Biostratigraphic and geochronologic constraints on early animal evolution. Science 270:598-604.
Meyer, SC (2004) The origin of biological information and the higher taxonomic categories. Proceedings of the Biological Society of Washington 117(2):213-239.