Contents
Prologue
Part One: The Mystery of the Missing Fossils
1 - Darwin’s Nemesis
2 - The Burgess Bestiary
3 - Soft Bodies and Hard Facts
4 - The Not Missing Fossils?
5 - The Genes Tell the Story?
6 - The Animal Tree of Life
7 - Punk Eek!
Part Two: How to Build an Animal
8 - The Cambrian Information Explosion
9 - Combinatorial Inflation
10 - The Origin of Genes and Proteins
11 - Assume a Gene
12 - Complex Adaptations and the Neo-Darwinian Math
13 - The Origin of Body Plans
14 - The Epigenetic Revolution
Part Three: After Darwin, What?
15 - The Post-Darwinian World and Self-Organization
16 - Other Post-Neo-Darwinian Models
17 - The Possibility of Intelligent Design
18 - Signs of Design in the Cambrian Explosion
19 - The Rules of Science
20 - What’s at Stake
Notes
Bibliography
Credits and Permissions
Index
Acknowledgments
Photographic Insert
Copyright
About the Publisher
Prologue
When people today hear the term “information revolution,” they typically think of silicon chips and software code, cellular phones and supercomputers. They rarely think of tiny one-celled organisms or the rise of animal life. But, while writing these words in the summer of 2012, I am sitting at the end of a narrow medieval street in Cambridge, England, where more than half a century ago a far-reaching information revolution began in biology. This revolution was launched by an unlikely but now immortalized pair of scientists, Francis Crick and James Watson. Since my time as a Ph.D. student at Cambridge during the late 1980s, I have been fascinated by the way their discovery transformed our understanding of the nature of life. Indeed, since the 1950s, when Watson and Crick first illuminated the chemical structure and information-bearing properties of DNA, biologists have come to understand that living things, as much as high-tech devices, depend upon digital information—information that, in the case of life, is stored in a four-character chemical code embedded within the twisting figure of a double helix.
Because of the importance of information to living things, it has now become apparent that many distinct “information revolutions” have occurred in the history of life—not revolutions of human discovery or invention, but revolutions involving dramatic increases in the information present within the living world itself. Scientists now know that building a living organism requires information, and building a fundamentally new form of life from a simpler form of life requires an immense amount of new information. Thus, wherever the fossil record testifies to the origin of a completely new form of animal life—a pulse of biological innovation—it also testifies to a significant increase in the information content of the biosphere.
In 2009, I wrote a book called Signature in the Cell about the first “information revolution” in the history of life—the one that occurred with the origin of the first life on earth. My book described how discoveries in molecular biology during the 1950s and 1960s established that DNA contains information in digital form, with its four chemical subunits (called nucleotide bases) functioning like letters in a written language or symbols in a computer code. And molecular biology also revealed that cells employ a complex information-processing system to access and express the information stored in DNA as they use that information to build the proteins and protein machines that they need to stay alive. Scientists attempting to explain the origin of life must explain how both information-rich molecules and the cell’s information-processing system arose.
The type of information present in living cells—that is, “specified” information in which the sequence of characters matters to the function of the sequence as a whole—has generated an acute mystery. No undirected physical or chemical process has demonstrated the capacity to produce specified information starting “from purely physical or chemical” precursors. For this reason, chemical evolutionary theories have failed to solve the mystery of the origin of first life—a claim that few mainstream evolutionary theorists now dispute.
In Signature in the Cell, I not only reported the well-known impasse in origin-of-life studies; I also made an affirmative case for the theory of intelligent design. Although we don’t know of a material cause that generates functioning digital code from physical or chemical precursors, we do know—based upon our uniform and repeated experience—of one type of cause that has demonstrated the power to produce this type of information. That cause is intelligence or mind. As information theorist Henry Quastler observed, “The creation of information is habitually associated with conscious activity.”1 Whenever we find functional information—whether embedded in a radio signal, carved in a stone monument, etched on a magnetic disc, or produced by an origin-of-life scientist attempting to engineer a self-replicating molecule—and we trace that information back to its ultimate source, invariably we come to a mind, not merely a material process. For this reason, the discovery of digital information in even the simplest living cells indicates the prior activity of a designing intelligence at work in the origin of the first life.
My book proved controversial, but in an unexpected way. Though I clearly stated that I was writing about the origin of the first life and about theories of chemical evolution that attempt to explain it from simpler preexisting chemicals, many critics responded as if I had written another book altogether. Indeed, few attempted to refute my book’s actual thesis that intelligent design provides the best explanation for the origin of the information necessary to produce the first life. Instead, most criticized the book as if it had presented a critique of the standard neo-Darwinian theories of biological evolution—theories that attempt to account for the origin of new forms of life from simpler preexisting forms of life. Thus, to refute my claim that no chemical evolutionary processes had demonstrated the power to explain the ultimate origin of information in the DNA (or RNA) necessary to produce life from simpler preexisting chemicals in the first place, many critics cited processes at work in already living organisms—in particular, the process of natural selection acting on random mutations in already existing sections of information-rich DNA. In other words, these critics cited an undirected process that acts on preexistent information-rich DNA to refute my argument about the failure of undirected material processes to produce information in DNA in the first place.2
For example, the eminent evolutionary biologist Francisco Ayala attempted to refute Signature by arguing that evidence from the DNA of humans and lower primates showed that the genomes of these organisms had arisen as the result of an unguided, rather than intelligently designed, process—even though my book did not address the question of human evolution or attempt to explain the origin of the human genome, and even though the process to which Ayala alluded clearly presupposed the existence of another information-rich genome in some hypothetical lower primate.3
Other discussions of the book cited the mammalian immune system as an example of the power of natural selection and mutation to generate new biological information, even though the mammalian immune system can only perform the marvels it does because its mammalian hosts are already alive, and even though the mammalian immune system depends upon an elaborately preprogrammed form of adaptive capacity rich in genetic information—one that arose long after the origin of the first life. Another critic steadfastly maintained that “Meyer’s main argument” concerns “the inability of random mutation and selection to add information to [
preexisting] DNA”4 and attempted to refute the book’s presumed critique of the neo-Darwinian mechanism of biological evolution accordingly.
I found this all a bit surreal, as if I had wandered into a lost chapter from a Kafka novel. Signature in the Cell simply did not critique the theory of biological evolution, nor did it ask whether mutation and selection can add new information to preexisting information-rich DNA. To imply otherwise, as many of my critics did, was simply to erect a straw man.
To those unfamiliar with the particular problems faced by scientists trying to explain the origin of life, it might not seem obvious why invoking natural selection does not help to explain the origin of the first life. After all, if natural selection and random mutations can generate new information in living organisms, why can it also not do so in a prebiotic environment? But the distinction between a biological and prebiotic context was crucially important to my argument. Natural selection assumes the existence of living organisms with a capacity to reproduce. Yet self-replication in all extant cells depends upon information-rich proteins and nucleic acids (DNA and RNA), and the origin of such information-rich molecules is precisely what origin-of-life research needs to explain. That’s why Theodosius Dobzhansky, one of the founders of the modern neo-Darwinian synthesis, can state flatly, “Prebiological natural selection is a contradiction in terms.”5 Or, as Nobel Prize–winning molecular biologist and origin-of-life researcher Christian de Duve explains, theories of prebiotic natural selection fail because they “need information which implies they have to presuppose what is to be explained in the first place.”6 Clearly, it is not sufficient to invoke a process that commences only once life has begun, or once biological information has arisen, to explain the origin of life or the origin of the information necessary to produce it.
All this notwithstanding, I have long been aware of strong reasons for doubting that mutation and selection can add enough new information of the right kind to account for large-scale, or “macroevolutionary,” innovations—the various information revolutions that have occurred after the origin of life. For this reason, I have found it increasingly tedious to have to concede, if only for the sake of argument, the substance of claims I think likely to be false.
And so the repeated prodding of my critics has paid off. Even though I did not write the book or make the argument that many of my critics critiqued in responding to Signature in the Cell, I have decided to write that book. And this is that book.
Of course, it might have seemed a safer course to leave well enough alone. Many evolutionary biologists now grudgingly acknowledge that no chemical evolutionary theory has offered an adequate explanation of the origin of life or the ultimate origin of the information necessary to produce it. Why press a point you never made in the first place?
Because despite the widespread impression to the contrary—conveyed by textbooks, the popular media, and spokespersons for official science—the orthodox neo-Darwinian theory of biological evolution has reached an impasse nearly as acute as the one faced by chemical evolutionary theory. Leading figures in several subdisciplines of biology—cell biology, developmental biology, molecular biology, paleontology, and even evolutionary biology—now openly criticize key tenets of the modern version of Darwinian theory in the peer-reviewed technical literature. Since 1980, when Harvard paleontologist Stephen Jay Gould declared that neo-Darwinism “is effectively dead, despite its persistence as textbook orthodoxy,”7 the weight of critical opinion in biology has grown steadily with each passing year.
A steady stream of technical articles and books have cast new doubt on the creative power of the mutation and selection mechanism.8 So well established are these doubts that prominent evolutionary theorists must now periodically assure the public, as biologist Douglas Futuyma has done, that “just because we don’t know how evolution occurred, does not justify doubt about whether it occurred.”9 Some leading evolutionary biologists, particularly those associated with a group of scientists known as the “Altenberg 16,” are openly calling for a new theory of evolution because they doubt the creative power of the mutation and natural selection mechanism.10
The fundamental problem confronting neo-Darwinism, as with chemical evolutionary theory, is the problem of the origin of new biological information. Though neo-Darwinists often dismiss the problem of the origin of life as an isolated anomaly, leading theoreticians acknowledge that neo-Darwinism has also failed to explain the source of novel variation without which natural selection can do nothing—a problem equivalent to the problem of the origin of biological information. Indeed, the problem of the origin of information lies at the root of a host of other acknowledged problems in contemporary Darwinian theory—from the origin of new body plans to the origin of complex structures and systems such as wings, feathers, eyes, echolocation, blood clotting, molecular machines, the amniotic egg, skin, nervous systems, and multicellularity, to name just a few.
At the same time, classical examples illustrating the prowess of natural selection and random mutations do not involve the creation of novel genetic information. Many biology texts tell, for example, about the famous finches in the Galápagos Islands, whose beaks have varied in shape and length over time. They also recall how moth populations in England darkened and then lightened in response to varying levels of industrial pollution. Such episodes are often presented as conclusive evidence for the power of evolution. And indeed they are, depending on how one defines “evolution.” That term has many meanings, and few biology textbooks distinguish between them. “Evolution” can refer to anything from trivial cyclical change within the limits of a preexisting gene pool to the creation of entirely novel genetic information and structure as the result of natural selection acting on random mutations. As a host of distinguished biologists have explained in recent technical papers, small-scale, or “microevolutionary,” change cannot be extrapolated to explain large-scale, or “macroevolutionary,” innovation.11 For the most part, microevolutionary changes (such as variation in color or shape) merely utilize or express existing genetic information, while the macroevolutionary change necessary to assemble new organs or whole body plans requires the creation of entirely new information. As an increasing number of evolutionary biologists have noted, natural selection explains “only the survival of the fittest, not the arrival of the fittest.”12 The technical literature in biology is now replete with world-class biologists13 routinely expressing doubts about various aspects of neo-Darwinian theory, and especially about its central tenet, namely, the alleged creative power of the natural selection and mutation mechanism.
Nevertheless, popular defenses of the theory continue apace, rarely if ever acknowledging the growing body of critical scientific opinion about the standing of the theory. Rarely has there been such a great disparity between the popular perception of a theory and its actual standing in the relevant peer-reviewed scientific literature. Today modern neo-Darwinism seems to enjoy almost universal acclaim among science journalists and bloggers, biology textbook writers, and other popular spokespersons for science as the great unifying theory of all biology. High-school and college textbooks present its tenets without qualification and do not acknowledge the existence of any significant scientific criticism of it. At the same time, official scientific organizations—such as the National Academy of Sciences (NAS), the American Association for the Advancement of Sciences (AAAS), and the National Association of Biology Teachers (NABT)—routinely assure the public that the contemporary version of Darwinian theory enjoys unequivocal support among qualified scientists and that the evidence of biology overwhelmingly supports the theory. For example, in 2006 the AAAS declared, “There is no significant controversy within the scientific community about the validity of the theory of evolution.”14 The media dutifully echo these pronouncements. As New York Times science writer Cornelia Dean asserted in 2007, “There is no credible scientific challenge to the theory of evolution as an explanation for the complexity and diversity of life on earth.”15
The extent of the disparity between popular representations of the status of the theory and its actual status, as indicated in the peer-reviewed technical journals, came home to me with particular poignancy as I was preparing to testify before the Texas State Board of Education in 2009. At the time the board was considering the adoption of a provision in its science education standards that would encourage teachers to inform students of both the strengths and weaknesses of scientific theories. This provision had become a political hot potato after several groups asserted that “teaching strengths and weaknesses” were code words for biblical creationism or for removing the teaching of the theory of evolution from the curriculum. Nevertheless, after defenders of the provision insisted that it neither sanctioned teaching creationism nor censored evolutionary theory, opponents of the provision shifted their ground. They attacked the provision by insisting that there was no need to consider weaknesses in modern evolutionary theory because, as Eugenie Scott, spokeswoman for the National Center for Science Education, insisted in The Dallas Morning News, “There are no weaknesses in the theory of evolution.”16
At the same time, I was preparing a binder of one hundred peer-reviewed scientific articles in which biologists described significant problems with the theory—a binder later presented to the board during my testimony. So I knew—unequivocally—that Dr. Scott was misrepresenting the status of scientific opinion about the theory in the relevant scientific literature. I also knew that her attempts to prevent students from hearing about significant problems with evolutionary theory would have likely made Charles Darwin himself uncomfortable. In On the Origin of Species, Darwin openly acknowledged important weaknesses in his theory and professed his own doubts about key aspects of it. Yet today’s public defenders of a Darwin-only science curriculum apparently do not want these, or any other scientific doubts about contemporary Darwinian theory, reported to students.
Darwin's Doubt Page 1