Stephen Meyer sought the opportunity to reply, in the pages of Science, to UC Berkeley paleontologist Charles Marshall, who reviewed Darwin’s Doubt in the same publication. Without explantion, the editors refused to publish the letter. We offer it for your interest. See here for more detailed replies by Meyer to Marshall’s review.
To the Editor:
Charles Marshall’s review of Darwin’s Doubt ("When Prior Belief Trumps Scholarship," Science, September 20) inadvertently demonstrates the severity of the central problem addressed in the book — i.e., the origin of morphological novelty in the Cambrian period.
Marshall speculates that developmental gene regulatory networks (dGRNs), essential for morphogenesis in metazoans, must have been more labile in the past.1 He affirms this to challenge my contention that the observed inflexibility of these regulatory networks represents a major impediment to the evolutionary transformation of one animal body plan into another. Yet evidence from numerous mutagenesis studies of different biological model systems establishes that dGRNs do not tolerate perturbations to their basic control logic as Marshall himself acknowledges.2 Instead, mutation-induced changes to genes present in dGRNs either produce no change in the developmental trajectory of animals (due to pre-programmed buffering or redundancy) or they produce catastrophic (usually, lethal) effects.3
By disregarding this evidence, Marshall reverses the epistemological priority of the uniformitarian method as pioneered by Lyell and Darwin.4 Rather than treating our present experimentally based knowledge as the key to evaluating the plausibility of theories about the past, Marshall uses an evolutionary assumption about what must have happened in the past (transmutation) to justify disregarding experimentally based knowledge of what does, and does not, occur in biological systems. The requirements of evolutionary doctrine trump observations about how organisms actually behave.
Marshall also disputes my claim that building Cambrian animals would require large amounts of new genetic information.5 Instead, he proposes that "rewiring" gene regulatory networks of "already existing genes" can account for the origin of Cambrian animals."6 This question-begging proposal does not solve the problem of the origin of the genetic information necessary to produce these animals. It merely pushes the problem back in time and overlooks the informational input required to "rewire" such a network.
Stephen C. Meyer
Discovery Institute, Seattle, Washington
Author, Darwin’s Doubt: The Explosive Origin of Animal Life and the Case for Intelligent Design
(1) Charles R. Marshall, "When Prior Belief Trumps Scholarship," Science, 341 (September 20, 2013): 1344.
(2) See N.H. Shubin and C.R. Marshall, "Fossils, Genes, and the Origin of Novelty," Paleobiology 26, no. 4, Supplement (2000): 335. P. Oliveri, Q. Tu, and E. H. Davidson, "Global Regulatory Logic for Specification of an Embryonic Cell Lineage," Proceedings of the National Academy of Sciences USA, 105 (2008): 5955-62.
(3) Eric H. Davidson, "Evolutionary Bioscience as Regulatory Systems Biology," Developmental Biology, 357 (September 1, 2011): 35-40. See also: Stephen C. Meyer, Darwin’s Doubt: The Explosive Origin of Animal Life and the Case for Intelligent Design, HarperOne, 2013, pp. 264-270.
(4) See Charles Lyell, Principles of Geology: Being an Attempt to Explain the Former Changes of the Earth’s Surface, by Reference to Causes Now in Operation. 3 vols. London: Murray, 1830-33, pp. 75-91.
(5) Marshall, "When Prior Belief Trumps Scholarship," 1344.
(6) Ibid. (Emphasis added). See also: Charles R. Marshall, "Explaining the Cambrian ‘Explosion’ of Animals," Annual Reviews of Earth and Planetary Sciences, Vol. 34:355-384 (2006); Charles R. Marshall, "Nomothetism and Understanding the Cambrian ‘Explosion’," Palaois, Vol. 18(3): 195-196 (June, 2003); M. Paul Smith and David A. T. Harper, "Causes of the Cambrian Explosion," Science, 341: 1355-1356 (September 20, 2013).