Meyer's Hopeless
Monster
Review of Meyer, Stephen C. 2004.
The origin of biological information and the higher taxonomic categories.
Proceedings of the Biological Society of Washington 117(2):213-239.
by Alan Gishlick, Nick Matzke, and
Wesley R. Elsberry
Posted September 12, 2004
[The views and statements expressed
here are our own and not necessarily those of NCSE or its supporters.]
"Intelligent design" (ID) advocate
Stephen C. Meyer has produced a "review article" that folds the various lines
of "intelligent design" antievolutionary argumentation into one lump. The
article is published in the journal Proceedings of the Biological Society of Washington.
We congratulate ID on finally getting an article in a peer-reviewed biology
journal, a mere fifteen years after the publication of the 1989 ID textbook Of
Pandas and People, a textbook aimed at inserting ID into public
schools. It is gratifying to see the ID movement finally attempt
to make their case to the only scientifically relevant group, professional
biologists. This is therefore the beginning (not the end) of the review
process for ID. Perhaps one day the scientific community will be
convinced that ID is worthwhile. Only through this route -- convincing the
scientific community, a route already taken by plate tectonics, endosymbiosis,
and other revolutionary scientific ideas -- can ID earn a legitimate place in
textbooks.
Unfortunately, the ID movement will
likely ignore the above considerations about how scientific review actually
works, and instead trumpet the paper from coast to coast as proving the
scientific legitimacy of ID. Therefore, we would like to do our part in
the review process by providing a preliminary evaluation of the claims made in
Meyer's paper. Given the scientific stakes, we may assume that Meyer, Program
Director of the Discovery Institute's Center for Science and
Culture, the major organization promoting ID, has put forward the best case
that ID has to offer. Discouragingly, it appears that ID's best case is
not very good. We cannot review every problem with Meyer's article in
this initial post, but we would like to highlight some of the most serious
mistakes. These include errors in facts and reasoning. Even more
seriously, Meyer's paper omits discussion or even citation of vast amounts of
directly relevant work available in the scientific literature.
Summary of the paper
Meyer's paper predictably follows the
same pattern that has characterized "intelligent design" since its inception:
deny the sufficiency of evolutionary processes to account for life's history
and diversity, then assert that an "intelligent designer" provides a better explanation.
Although ID is discussed in the concluding section of the paper, there is no
positive account of "intelligent design" presented, just as in all previous
work on "intelligent design". Just as a detective doesn't have a case
against someone without motive, means, and opportunity, ID doesn't stand a
scientific chance without some kind of model of what happened, how, and
why. Only a reasonably detailed model could provide explanatory
hypotheses that can be empirically tested. "An unknown intelligent
designer did something, somewhere, somehow, for no apparent reason" is not a
model.
Meyer's paper, therefore, is almost
entirely based on negative argument. He focuses upon the Cambrian
explosion as an event he thinks that evolutionary biology is unable to account
for. Meyer asserts that the Cambrian explosion represented an actual sudden
origin of higher taxa; that these taxa (such as phyla) are "real" and not an
artifact of human retrospective classification; and that morphological
disparity coincides with phyletic categories. Meyer then argues that the
origin of these phyla would require dramatic increases in biological
"information," namely new proteins and new genes (and some vaguer forms of
"information" at higher levels of biological organization). He argues
that genes/proteins are highly "complex" and "specified," and that therefore
the evolutionary origin of new genes is so improbable as to be effectively
impossible. Meyer briefly considers and rejects several theories proposed
within evolutionary biology that deal with macroevolutionary phenomena.
Having rejected these, Meyer argues that ID is a better alternative explanation
for the emergence of new taxa in the Cambrian explosion, based solely upon an
analogy between "designs" in biology and the designs of human designers
observed in everyday experience.
The mistakes and omissions in Meyer's
work are many and varied, and often layered on top of each other. Not
every aspect of Meyer's work can be addressed in this initial review, so we
have chosen several of Meyer's major claims to assess. Among these, we
will take up the Cambrian explosion and its relation to paleontology and
systematics. We will examine Meyer's negative arguments concerning evolutionary
theories and the origin of biological "information" in the form of genes.
An expanded critique of this paper is
in preparation.
Playing with Dynamite: The Cambrian
Explosion
The Cambrian explosion is a standard
topic for antievolutionists. There are several reasons for this: many taxa make
their first appearance in the Cambrian explosion; the amount of time within the
period of the Cambrian explosion is geologically brief; and we have limited
evidence from both within and before the Cambrian explosion on which to base
analysis. The first two factors form the basis of an antievolutionary argument
that evolutionary processes are insufficient to generate the observed range of
diversity within the limited time available. The last factor is a general
feature of the sorts of phenomena that antievolutionists prefer: not enough
evidence has yet accrued to single out a definitive scientific account, so it
is rhetorically easy for a pseudoscientific "alternative" to be offered as a
competitor. In Meyer's closing paragraph, he mentions "experience-based analysis."
The consistent experience of biologists is that when we have sufficient
evidence bearing upon some aspect of biological origins, evolutionary theories
form the basis of explanation of those phenomena (an example where much
evidence has become available recently is the origin of birds and bird flight;
see Gishlick 2004).
Problems with Meyer's discussion of
the Cambrian Explosion:
1. Meyer tries to evaluate
morphological evolution by counting taxa, a totally meaningless endeavor for
investigating the evolution of morphology. Most paleontologists gave up
taxa-counting long ago and moved on to more useful realms of research regarding
the Cambrian (see Budd and Jensen 2000). This is perhaps why most of Meyer's
citations for this section are to his own articles (themselves not in relevant
scientific journals).
2. Meyer repeats the claim that there
are no transitional fossils for the Cambrian phyla. This is a standard ploy of
the Young-Earth Creationists (see Padian and Angielczyk 1999 for extended discussion
of this tactic and its problems). Meyer shows a complete lack of understanding
of both the fossil record and the transitional morphologies it exhibits (even
during the Cambrian explosion; for a recent example of transitional forms in
the Cambrian explosion see Shu et al. 2004) as well as the literature he
himself cites. (This topic has been dealt with before, as with DI Fellow
Jonathan Wells. See Gishlick 2002 at http://www.ncseweb.org/icons/icon2tol.html.)
3. Meyer attempts to argue that the
"gaps" in the fossil record reflect an actual lack of ancestors for Cambrian
phyla and subphyla. To support this, Meyer cites some papers by
University of Chicago reasearcher Mike Foote. However, of the two papers
by Foote cited by Meyer, neither deals with the Cambrian/Precambrian records
(one concerns the Middle and Late Paleozoic records of crinoids and
brachiopods, the other the Mesozoic record of mammal clade divergence), or even
transitional fossils. Foote's papers deal with issues of taxonomic sampling:
How well does a fossil record sample for a given time period reflect the
biodiversity of that period? How well does a given fossil record pinpoint
divergence times? Foote's conclusions are that we have a good handle on past
biodiversity, and that divergence times probably match appearance in the fossil
record relatively closely. But Foote's work utilizes organisms that are readily
preserved. It doesn't deal with organisms that aren't readily preserved,
a trait that almost certainly applies to the near-microscopic, soft-bodied
ancestors of the Cambrian animals. According to Meyer's argument, which
doesn't take into account preservation potential, microscopic metazoans such as
rotifers must have arisen recently because they entirely lack a fossil record.
Neither of Foote's papers supports Meyer's contention that the lack of
transitional fossils prior to the Cambrian indicates a lack of ancestors.
Lastly, it appears that fossils of the long-hypothesized small, soft-bodied
precambrian worms have recently been discovered (Chen et al. 2004).
Information and Misinformation
For some, "information theory" is
simply another source of bafflegab. And that appears to be the only role Meyer
sees for "information theory". After brief nods to Shannon and algorithmic
information theory, Meyer leaves the realm of established and accepted
information theoretic work entirely.
1. Meyer invokes Dembski's "specified
complexity"/"complex specified information" (SC/CSI) as somehow relevant to the
Cambrian explosion. However, under Dembski's technical definition, CSI is not
just the conjoint use of the nontechnical words "specified" (as in
"functional") and "complexity", as Meyer erroneously asserts. According
to Dembski's technical definition, improbability of appearance under natural
causes is part of the *definition* of CSI. Only after one has determined
that something is wildly improbable under natural causes can one conclude that
something has CSI. You can't just say, "boy, that sure is specific and
complicated, it must have lots of CSI" and conclude that evolution is
impossible. Therefore, Meyer's waving about of the term "CSI" as evidence
against evolution is both useless for his argument, and an incorrect usage of
Dembski (although Dembski himself is very inconsistent, conflating popular and
technical uses of his "CSI," which is almost certainly why Meyer made this
mistake. See here
for examples of definitional inconsistency.).
2. Meyer relies on Dembski's
"specified complexity," but even if he used it correctly (by rigorously
applying Dembski's filter, criteria, and probability calculations), Dembski's
filter has never been demonstrated to be able to distinguish anything in the
biological realm -- it has never been successfully applied by anyone to any
biological phenomena (Elsberry and Shallit, 2003).
3. Meyer claims, "The Cambrian
explosion represents a remarkable jump in the specified complexity or 'complex
specified information' (CSI) of the biological world." Yet to substantiate
this, Meyer would have to yield up the details of the application of Dembski's
"generic chance elimination argument" to this event, which he does not do.
There's small wonder in that, for the total number of attempted uses of
Dembski's CSI in any even partially rigorous way number a meager four (Elsberry
and Shallit, 2003).
4. Meyer claims, "One way to estimate
the amount of new CSI that appeared with the Cambrian animals is to count the
number of new cell types that emerged with them (Valentine 1995:91-93)"
(p.217). This may be an estimate of something, and at least signals some sort
of quantitative approach, but we may be certain that the quantity found has
nothing to do with Dembski's CSI. The quantitative element of Dembski's CSI is
an estimate of the probability of appearance (under natural processes or random
assembly, as Dembski shifts background assumptions opportunistically), and has
nothing to do with counting numbers of cell types.
Of Text and Peptides
1. Meyer argues that "many scientists
and mathematicians have questioned the ability of mutation and selection to
generate information in the form of novel genes and proteins" (p. 218).
He makes statements to this effect throughout the paper. Meyer does not
say who these scientists are, and in particular does not say whether or not any
of them are biologists. The origin of new genes and proteins is actually
a common, fairly trivial event, well-known to anyone who spends a modicum of
effort investigating the scientific literature. The evolution of new
genes has been observed in the lab, in the wild, inferred in great detail
between closely-related modern species, and reconstructed in hundreds of cases
by comparing the genomes from organisms sequenced in genome projects over the
last decade (see Long 2001 and related articles, and below).
2. Meyer compares DNA sequences to
human language. In this he follows Denton's (1986) Evolution: A Theory
in Crisis. Denton (1986) argued that meaningful sentences are
isolated from each other: it is usually impossible to convert one sentence to
another via a series of random letter changes, where each intermediate sentence
has meaning. Like Denton (1986), Meyer applies the same argument to gene and
protein sequences, concluding that they, like meaningful sentences, must have been
produced by intelligent agents. The analogy between language and
biological sequence is poor for many reasons; starting with the most obvious
point of disanalogy, proteins can lose 80% or more of their sequence similarity
and retain the same structure and function (a random example is here). Let's examine an English phrase where four out of
five characters have been replaced with a randomly generated text string.
See if you can determine the original meaning of this text string:
Tnbpursutd euckilecuitn
tiioismdeetneia niophvlgorciizooltccilhseema er [1]
Eighty percent loss of sequence
identity is fatal to English sentences. Clearly proteins are much less
specified than language.
3. Meyer cites Denton (1986)
unhesitatingly. This is surprising because, while Denton advocated in
1986 that biology adopt a typological view of life, he has abandoned this view
(Denton 1998). Among other things, Denton wrote, "One of the most
surprising discoveries which has arisen from DNA sequencing has been the
remarkable finding that the genomes of all organisms are clustered very close
together in a tiny region of DNA sequence space forming a tree of related
sequences that can all be interconverted via a series of tiny incremental
natural steps." (p. 276) Denton now accepts common descent and disagrees
with the "intelligent design" advocates who conjecture the special creation of
biological groups, regularly criticizing them for ignoring the overwhelming
evidence (Denton 1999).
4. Meyer's case that the evolution of
new genes and proteins is essentially impossible relies on just a few
references from the scientific literature. For example, Meyer references Taylor
et al. 2001, a paper entitled "Searching sequence space for protein catalysts"
and available online at the PNAS website. But Taylor et al.'s recommendation
for intelligent protein design is actually that it should mimic natural
evolution: "[A]s in natural evolution, the design of new enzymes will require
incremental strategies...".
There is a large mass of evidence
supporting the view that proteins are far less "specified" than Meyer
asserts. Fully reviewing this would require an article in itself, and
would be somewhat beside the point since Meyer's claim is categorically
disproven by the recent origin of novel genes by natural processes.
(Another way in which "experience-based analysis" leads one to conclusions
other than those Meyer asserts.) However, some idea of the diversity of protein
solutions to any given enzymatic "problem" is given at the NCBI's Analogous Enzymes webpage, which includes hundreds of
examples. There is more than one way to skin a cat, and there are many
more ways to evolve a solution to any given functional "problem" in biology.
The origin of novel genes/proteins
Meyer makes his case that evolution
can't produce new genes in complete neglect of the relevant scientific
literature documenting the origin of new genes.
1. A central claim of Meyer's is that
novel genes have too much "CSI" to be produced by evolution. The first problem
with this is that Meyer does not demonstrate that genes have CSI under
Dembski's definition (see above). The second problem is that Meyer cites
absolutely none of the literature documenting the origin of new genes.
For example, Meyer missed the recent paper in Current Opinion in Genetics
and Development with the unambiguous title, "Evolution of novel genes." The
paper and 183 related papers can be found here. Many other references can be found linked from here.
It is worth listing a few in-text to
make crystal-clear the kinds of references that Meyer missed:
Copley, S. D. (2000). "Evolution of a
metabolic pathway for degradation of a toxic xenobiotic: the patchwork
approach." Trends Biochem Sci 25(6): 261-265. PubMed
Harding, M. M., Anderberg, P. I. and
Haymet, A. D. (2003). "'Antifreeze' glycoproteins from polar fish." Eur J
Biochem 270(7): 1381-1392. PubMed
Johnson, G. R., Jain, R. K. and Spain,
J. C. (2002). "Origins of the 2,4-dinitrotoluene pathway." J Bacteriol
184(15): 4219-4232. PubMed
Long, M., Betran, E., Thornton, K. and
Wang, W. (2003). "The origin of new genes: glimpses from the young and old." Nat
Rev Genet 4(11): 865-875. PubMed
Nurminsky, D., Aguiar, D. D.,
Bustamante, C. D. and Hartl, D. L. (2001). "Chromosomal effects of rapid gene
evolution in Drosophila melanogaster." Science 291(5501): 128-130. PubMed
Patthy, L. (2003). "Modular assembly
of genes and the evolution of new functions." Genetica 118(2-3):
217-231. PubMed
Prijambada I. D., Negoro S., Yomo T.,
Urabe I. (1995). "Emergence of nylon oligomer degradation enzymes in
Pseudomonas aeruginosa PAO through experimental evolution." Appl Environ
Microbiol. 61(5):2020-2. PubMed
Ranz, J. M., Ponce, A. R., Hartl, D.
L. and Nurminsky, D. (2003). "Origin and evolution of a new gene expressed in
the Drosophila sperm axoneme." Genetica 118(2-3): 233-244. PubMed
Seffernick, J. L. and Wackett, L. P.
(2001). "Rapid evolution of bacterial catabolic enzymes: a case study with
atrazine chlorohydrolase." Biochemistry 40(43): 12747-12753. PubMed
2. Meyer cites Axe (2000) as a counter
to the evolutionary scenario of successive modifications of genes leading to
new protein products. But Axe (2000) is not in any sense about "successive
modifications"; Axe modified proteins in several locations at a time. ID
advocates love to cite certain Axe papers that indicate that functional proteins
are rare in sequence space, but not others that indicate the opposite (Axe et
al., 1996). Axe apparently
said in 1999 that his work had no relevance to intelligent design.
3. Meyer portrays protein function as
all-or-nothing. But protein function is not all-or-nothing. Recent research
highlights several evolutionary mechanisms "tinkering" with existing genes to
arrive at new genes (Prijambada et al. 1995; Long 2001). But you won't learn
about that from Meyer.
4. As far as we can tell, Meyer uses
the word "duplication" or something similar only twice in the entire 26-page
article. One of these usages is in the references, in the title of an
article referring to centriole duplication. The other is on p. 217, where
Meyer introduces the genes-from-unnecessary DNA scenario. However, he
subsequently ignores duplicated functional genes in this section and focuses on
the origin of genes from noncoding DNA. Duplication really belongs with Meyer's
section on the second evolutionary scenario, the origin of genes from coding
DNA. There, Meyer argued that the origin of new genes from old genes was
impossible because such a process would mess up the function of the old genes.
If he had put it there, he would have revealed the existence of the extremely
simple, and already well-known, solution to the problem that he posed, namely,
gene duplication (Lynch and Conery, 2000, 2003).
5. Meyer relies heavily on a new paper
by Axe published in the Journal of Molecular Biology. Meyer alleges that
Axe (2004) proves that, "the probability of finding a functional protein among
the possible amino acid sequences corresponding to a 150-residue protein is
similarly 1 in 10^77." But Axe's actual conclusion is that the number is "in
the range of one in 10^77 to one in 10^53" (Axe 2004, p. 16). Meyer only
reports the lowest extreme. One in 10^53 is still a small number, but Meyer apparently
didn't feel comfortable mentioning those 24 orders of magnitude to his
reader. A full discussion of Axe (2004) will have to appear elsewhere,
but it is worth noting that Axe himself discusses at length the fact that the
results one gets in estimating the density of functional sequences depend
heavily on methods and assumptions. Axe uses a fairly restricted "target"
in his study, which gives a low number, but studies that just take random
sequences and assay them just for function -- which Meyer repeatedly insists is
all that matters in biology -- produce larger numbers (Axe 2004, pp. 1-2). [2]
We would like to pose a challenge to
Meyer. There are a large number of documented cases of the evolutionary
origin of new genes (again, a sample is here). We challenge Meyer to explain why he didn't
include them, or anything like them, in his review. We invite readers to
wait to see whether or not Meyer ever addresses them at a later date and
whether he can bring himself to admit that his most common, most frequent, and
most central assertion in his paper is wildly incorrect and widely known to be
so in the scientific literature. These points should not be
controversial: even Michael Behe, the leading IDist and author of Darwin's
Black Box, admits that novel genes can evolve: "Antibiotics and pesticide
resistance, antifreeze proteins in fish and plants, and more may indeed be explained
by a Darwinian mechanism." (Behe 2004, p. 356)
If we might be permitted a prediction,
Meyer or his defenders will respond not by admitting their error on this point,
but by engaging in calculated obfuscation over the definition of the words
"novel" and "fundamentally." They will then assert that, after all, yes,
evolution can produce new genes and new information, but not "fundamentally
new genes." They will never clarify what exactly counts as
fundamental novelty.
Morphological novelty
The origin of morphological novelty is
also a large topic with an extensive literature, but unfortunately we can only
discuss a limited number of topics in any depth here. To pick two issues,
Meyer fails to incorporate any of the work on the origin of morphological
novelties in geologically recent cases where evidence is fairly abundant, and
Meyer also fails to discuss the crucial role that cooption plays in the origin
of novelty. Below is a small sampling of the kinds of papers that Meyer
would have had to address in this field in order to even begin to make a case
that evolution cannot produce new morphologies:
Ganfornina M. D., Sanchez D. 1999.
"Generation of evolutionary novelty by functional shift." Bioessays.
21(5):432-9. PubMed
Mayr, E. 1960. "The Emergence of
Evolutionary Novelties." in Evolution After Darwin: Volume 1: The
Evolution of Life: Its Origin, History, and Future, Sol Tax, ed. The
University of Chicago Press, Chicago, IL. pp. 349-380.
Pellmyr, O. and Krenn, H. W., 2002.
"Origin of a complex key innovation in an obligate insect-plant mutualism." PNAS.
99(8):5498-5502. PubMed
Prum, R. O. and Brush, A. H., 2002.
"The evolutionary origin and diversification of feathers." Q Rev Biol.
77 (3), 261-295. PubMed
True, J. R. and Carroll, S. B., 2002.
"Gene co-option in physiological and morphological evolution." Annu Rev Cell
Dev Biol. 18, 53-80. PubMed
Mayr's paper in particular is a
well-known introduction to the topic. He emphasized the important role of
change-of-function for understanding the origin of new structures. In his
conclusion he wrote,
"The emergence of new structures is
normally due to the acquisition of a new function by an existing
structure. In both cases the resulting 'new' structure is merely a
modification of a preceding structure. The selection pressure in favor of
the structural modification is greatly increased by a shift into a new
ecological niche, by the acquisition of a new habit, or by both. A shift
in function exposes the fully formed 'preadapted' structure to the new
selection pressure. This, in most cases, explains how an incipient
structure could be favored by natural selection before reaching a size and
elaboration where it would be advantageous for a new role." (p. 377-378)
Mayr wrote this in 1960, at the
sprightly age of 56, but it applies rather well to discoveries about the origin
of new genes and new morphological structures made in the last few
decades. Most new genes and new structures are derived by
change-of-function from old genes and old structures, often after
duplication. Many other terms are used in the evolutionary literature for
this process (Mayr's "preadaptation", replaced by "exaptation" by Gould;
cooption; functional shift; tinkering; bricolage; see e.g. the commonly-cited
essay by Jacob 1977 for a discussion of the "tinkering" analogy for
evolution), but none of them appear in Meyer's essay.
The Power of Negative Thinking
Negative argumentation against
evolutionary theories seems to be the sole scientific content of "intelligent
design". That observation continues to hold true for this paper by Meyer.
1. Meyer gives no support for his
assertion that PE proponents proposed species selection to account for "large
morphological jumps". (Use of the singular, "punctuated equilibrium", is a
common feature of antievolution writing. It is relatively less common among
evolutionary biologists, who utilize the plural form, "punctuated equilibria",
as it was introduced by Eldredge and Gould in 1972.)
2. Meyer makes the false claim that PE
was supposed to address the problem of the origin of biological information or
form. As Gould and Eldredge 1977 noted, PE is a theory about speciation.
It is an application of Ernst Mayr's theory of allopatric speciation -- a theory
at the core of the Modern Synthesis -- to the fossil record. Any
discussion of PE that doesn't mention allopatric speciation or something similar
is ignoring the concept's original meaning.
3. Meyer also makes the false claim
that PE was supposed to address the origin of taxa higher than species. This
class of error was specifically addressed in Gould and Eldredge 1977. PE
is about the pattern of speciation observed in the fossil record, not about
taxa other than species.
4. Meyer makes the false claim that
genetic algorithms require a "target sequence" to work. Meyer cites two of his
own articles as the relevant authority in this matter. However, when one examines
these sources, one finds that what is cited in both of these earlier essays is
a block of three paragraphs, the content of which is almost identical in the
two essays. Meyer bases his denunciation of genetic algorithms as a field upon
a superficial examination of two cases. While some genetic algorithm
simulations for pedagogy do incorporate a "target sequence", it is utterly
false to say that all genetic algorithms do so. Meyer was in attendance at the
NTSE in 1997 when one of us [WRE] brought up a genetic algorithm to solve the
Traveling Salesman Problem, which was an example where no "target sequence" was
available. Whole fields of evolutionary computation are completely
overlooked by Meyer. Two citations relevant to Meyer's claims are Chellapilla
and Fogel (2001) and Stanley and Miikkulainen (2002). (That Meyer overlooks
Chelapilla and Fogel 2001 is even more baffling given that Dembski 2002
discussed the work.) Bibliographies for the entirely neglected fields of
artificial life and genetic programming are available at these sites:
http://users.ox.ac.uk/~econec/alife.html
http://www.cs.bham.ac.uk/~wbl/biblio/gp-bibliography.html.
A bibliography of genetic algorithms
and artificial neural networks is available here.
On the Other Hand: the View Meyer
Fails to Consider
When Meyer states that a massive
increase in information is required to create all the body plans of the living
"phyla" he is implying that evolution had to go from a single celled creature
to a complex metazoan in one step, which would be impossible. But the origin of
metazoans is not a case of zero to metazoan instantly. Rather, it involves a
series of incremental morphological steps. These steps become apparent
when the evolution of the major clades of metazoan life is viewed in a
phylogenetic context. The literature using this phylogenetic perspective is
extensive if Meyer wanted to investigate it (for example see Grande and Rieppel
eds. 1994, Carroll 1997, Harvey et al. eds. 1996). Certainly an acknowledgment
of such literature is crucial if one is going to discuss these topics in a
scholarly article, even if it was to criticize it. No discussion of an
evolutionary innovation would be complete without reference to the phylogeny,
and yet we find not one in Meyer's 26 page opus.
Perhaps the glaring absence of
phylogenies owes to Meyer's lack of acceptance of common descent, or perhaps it
is because when the relationships of the 'phyla' are seen in a phylogenetic
context, one readily sees that all of the complex developmental and
morphological features that diagnose the extant clades need not arise
simultaneously. Rather, they are added incrementally. First one cell type, then
three, multiple body layers, and bilateral symmetry. At this point you have a
"worm" and all the other bauplans are basically variations on the worm theme. There
are worms with guts, and worms with muscles, worms with segments, worms with
appendages, and even worms with a stiff tube in them (this last would be us).
Missing from Meyer's picture is any
actual discussion of the origins of metazoan development. Reading Meyer, one
would think that it is a giant mystery, but the real mystery is why Meyer does
not reference this huge area of research.
Meyer implies that the lack of
specificity of development in genes is a surprising problem for evolution, yet
it is well known and it is widely recognized that development is coordinated by
epigenetic interactions of various cell lineages. Meyer treats this fact as if
it were some mysterious phenomenon requiring a designer to input information.
But, just as the ordered structure of convection cells in a boiling pot of
water is not a mystery to physicists even though it is not specified by the
shapes of the component water molecules, neither are developmental programs to
biologists. The convection cells are an emergent property of the interactions
of the water molecules, just as the growth of organismal form is an emergent
property of the interactions of cell lineages.
It is thought that metazoan
development arose by competition between variant cell lineages that arose during
ontogeny, and thus its organization remains in the epigenetic interactions of
the various cell lineages (Buss 1987). This was extensively documented by Leo
Buss in 1987, but Meyer somehow failed to mention this seminal work on the
origin of metazoan development.
Understanding the interactions of
lineages and their various reciprocal inductions is crucial to understanding
the evolution of metazoan development and bodyplans. The study of this forms
the basis for the entire field of evolutionary and developmental biology, Meyer
acts like this field doesn't even exist, while citing sparingly from some of
its works. Also absent is any discussion of the difference between sorting and
selection (see Vrba and Gould 1986). The difference is crucial: sorting at one
level does not imply selection, but rather may be the result of selection at an
entirely different level of the organismal hierarchy. Meyer appears to be
completely unaware of this distinction when criticizing the inability of
selection to create new morphologies. In some cases novelty at one level in the
hierarchy may result when selection occurs somewhere else in the hierearchy:
the emergent morphology may actually be the result of a sorting cascade, rather
than direct selection. The evolution of metazoan bodyplans involved an exchange
between selection at the level of the individual and at the level of the cell
lineage, which was sorted through developmental interactions (Buss 1987) .
Finally, any discussion of development
and evolution would not be complete without dealing with the effects of
heterochrony on form, and here too we find relevant citations glaringly absent
despite the prominent place of heterochrony in the literature going back to de
Beer. This is 60 years of research missed by Meyer. (The oversight is worse
when one considers various contributing ideas in development that date back to
von Baer.)
Meyer repeatedly appeals to the notion
of an ur-cell metazoan ancestor that had all the genetic potentiality of the
different metazoan bauplanes. The reference to this hypothetical super-ancestor
is as popular with creationists as it is erroneous to biologists. While
biologists have at times proposed a need for such an ur-cell, this is no longer
particularly in vogue, because the recognition of hierarchy and epigenetic
processes and has removed the need for an all-encompassing ancestor.
There are many hierarchies that need
to be separated. There is the phylogenetic hierarchy (the order of character
acquisition in time), the developmental hierarchy (the order of cell
differentiation) and the structural hierarchy (the position of various parts in
an organism). Meyer muddles all of these together and treats them like they are
all the same thing, but they are not.
A Long Walk Off a Short Peer Review
The Proceedings of the Biological
Society of Washington (PBSW) is a respected, if somewhat obscure, biological
journal specializing in papers of a systematic and taxonomic nature, such as
the description of new species. A review of issues in evolutionary theory is
decidedly not its typical fare, even disregarding the creationist nature of
Meyer's paper. The fact that the paper is both out of the journal's typical
sphere of publication, as well as dismal scientifically, raises the question of
how it made it past peer review. The answer probably lies in the editor,
Richard von Sternberg. Sternberg happens to be a creationist and ID fellow
traveler who is on the editorial board of the Baraminology Study Group at Bryan College in Tennessee.
(The BSG is a research group devoted to the determination of the created kinds
of Genesis. We are NOT making this up!) Sternberg was also a signatory of the
Discovery Institute's "100 Scientists Who Doubt Darwinism" statement. [3] Given
R. v. Sternberg's creationist leanings, it seems plausible to surmise that the
paper received some editorial shepherding through the peer review process.
Given the abysmal quality of the science surrounding both information theory
and the Cambrian explosion, it seems unlikely that it received review by
experts in those fields. One wonders if the paper saw peer review at all.
Although this critique has focused on
the scientific problems with Meyer's paper, it may be worth briefly considering
the political dimensions, as the paper is likely to become part of the ID
creationists' lobbying machine. The paper has been out since early
August, so it is somewhat puzzling that the Discovery Institute and similar
groups have yet to publicize this major event for ID theory. Are they
embarrassed at its sub-par (even by ID standards) content, or are they are
waiting to spring it on some unsuspecting scientist at a future school board
meeting or state legislature hearing? Regardless, once the press releases
start to fly, responses to the paper should be careful to not assume facts not
in evidence (such as the review, or lack thereof, of Meyer's paper), and should
be careful to distinguish between issues that are scientifically important and
unimportant. Whether or not editorial discretion was abused in order to
enable "intelligent design" to make a coveted appearance in the peer-reviewed
scientific literature is not currently known, and is at any rate not the most
important issue. The important issue is whether or not the paper makes any
scientific contribution: does it propose a positive explanatory model? If
the paper is primarily negative critique, does it accurately review the science
it purports to criticize? The fact that a paper is shaky on these grounds
is much more important than the personalities involved. Intemperate
responses will only play into the hands of creationists, who might use these as
an excuse to say that the "dogmatic Darwinian thought police" are unfairly
giving Meyer and PBSW a hard time. Nor should Sternberg be given the
chance to become a "martyr for the cause." Any communication with PBSW
should focus upon the features that make this paper a poor choice for
publication: its many errors of fact, its glaring omissions of relevant
material, and its misrepresentations of the views that it does consider.
The ultimate test of the value of a
peer-reviewed paper is whether it spawns actual research and convinces
skeptics. Applicability and acceptance in science, not in politics, is the
ultimate test of proposed scientific ideas. As we have stated before, all ID
advocates have to do is demonstrate to scientists that they have something that
works. They need a positive research program showing scientists that ID has
more to offer than "Poof, ID did it."
Conclusion
There is nothing wrong with
challenging conventional wisdom -- continuing challenge is a core feature of
science. But challengers should at least be aware of, read, cite, and
specifically rebut the actual data that supports conventional wisdom, not
merely construct a rhetorical edifice out of omission of relevant facts,
selective quoting, bad analogies, knocking down strawmen, and tendentious
interpretations. Unless and until the "intelligent design" movement does
this, they are not seriously in the game. They're not even playing the same
sport.
Postscript
As we have said, the errors in this
paper are too numerous to document more than a few here. We invite
readers to find more mistakes and misrepresentations in this work and add them
to our comments section, and/or email them to us to add to the full online
critique.
Endnotes
[1] The original phrase was: "The
origin of biological information and the higher taxonomic categories", the
title of Meyer's paper. The random text was generated at the random text
generator webpage: http://barnyard.syr.edu/monkey.html...
[2] Page numbers for Axe (2004) in this
section refer to the in press, pre-publication version of Axe's paper availabe
on the JMB website: http://dx.doi.org/10.1016/j.jmb.2004.06.058.
[3] As mentioned previously, Meyer is
the directory the Discovery Institute's Center for Science and Culture. Meyer's
reported affiliation on the PBSW paper is to Palm Beach Atlantic University, which requires all faculty
to affirm the following
statement:
To assure the perpetuation of these
basic concepts of its founders, it is resolved that all those who become
associated with Palm Beach Atlantic as trustees, officers, members of the
faculty or of the staff, must believe that man was directly created by God.
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Discussion
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