The Edge of Evolution: The Search for the Limits of Darwinism Hardcover – June 5, 2007

In "The Edge of Evolution", Michael Behe looks to rigorously apply the data from quickly multiplying bacteria and viruses to Neo-Darwinian theory in general. Because organisms like malaria and HIV multiply so much more quickly than larger organisms like mammals, they provide an important check on evolutionary theory. Without such checks, ideas about how one feature developed can quickly devolve into just-so stories, high on imagination but low on evidence. The constraints imposed by malaria and HIV are described by Behe as the "edge" of evolution- it is what Darwinian mechanisms can reasonably be expected to accomplish in the conventional 4.5 billion year history of the Earth.

The opening argument of the book is so simple and obvious one wonders why one hasn't heard it before. In the past sixty years, man has thrown every drug he could at malaria. Malaria developed resistance to some within days. For others, it took years. But despite having millennia to evolve resistance, malaria has never developed a way to avoid being destroyed by the Sickle mutation, which changes the shape of human hemoglobin so that it gels in the presence of an invasive bacterium such as malaria. Likewise, malaria can only survive in warm climates. This fact is so obvious that it's difficult to perceive its significance. But on further reflection, its significance raises important questions for Darwinism. We are told that by random mutation and natural selection, Darwinian evolution can build sophisticated molecular machines. But despite the vast number of malarial cells (far more than all the mammals who have existed in the history of the Earth), malaria cannot evolve to survive in cooler climates?

This intuitive insight is then developed in a more rigorous fashion throughout the book. While malaria develops resistance to most drugs within days or weeks, it took ten years for it to develop resistance to Chloroquine. This is because chloroquine resistance requires two mutations, one of which, taken alone, is deleterious. Hence, the two mutations must appear simultaneously. Stepwise mechanisms are ruled out by natural selection, which would remove either mutation if it appeared alone. Because of the rapid speed at which malarial generations pass, adequate time is provided for random mutation to search sequence space. In order to acquire the probability of two mutations appearing simultaneously, one must square the probability of one mutation appearing. If the number of organisms exceeds that probability, then it is likely that the double-mutation will appear. But what if an organism needs three or more mutations? Well, then one would need to cube the probability, and then lift it to the fourth power. The probability decreases exponentially until it is beyond the number of all the organisms that have ever existed during the history of life on Earth.

That is how one arrives at the edge of evolution. The argument is concise, evidentially based, and persuasive. Apart from this, Behe explores the nature of beneficial mutation and the mechanism of design. As to the former, he points out that virtually all observed beneficial mutations operate by breaking a preexisting function in order to save energy. Rather than an arms race in which each side becomes more technically adept, Darwinism is trench warfare, where each side is progressively driven backwards by the necessity of moment-to-moment combat. As for the latter, Behe tentatively embraces a providential account of design, where God frontloaded the entire history of the cosmos into the Big Bang so that events of extraordinarily low probability would necessarily occur, including the development of intelligent life. I find this philosophically problematic, as it seems to presume determinism. But this is a minor flaw.

I have frankly been mystified by the poor quality of the responses to Dr. Behe's case. The abuse he has received is beyond the pale. Having read Kenneth Miller's critiques of this book, it is questionable as to whether he even understood the book's main argument. He has suggested that chloroquine resistance can evolve in stepwise fashion- this has now been experimentally disconfirmed, but besides that, it leaves him without an explanation of why it has arisen so rarely relative to resistance to other drugs. Others have responsed to Behe's suggestion that two new protein-protein binding sites are beyond the edge of evolution by pointing to new protein-viral binding sites, which Behe explicitly distinguished from protein-protein binding sites- a virus has many more options for binding, since it merely needs to break the function rather than perform a specified function in a molecular machine. And so on. Despite the vitriol, responses to the substance are lacking.

Highly recommended for those interested in the debate. Before you criticize intelligent design, read its most astute proponents and read their critics. You might be surprised.

In The Edge of Evolution: The Search for the Limits of Darwinism (2007), Michael Behe explores the statistical boundaries of random mutation and natural selection in light of recent scientific discoveries. Behe, who is probably most well known for his advocacy of intelligent design and his bestselling book, Darwin’s Black Box, holds a Ph.D. in biochemistry from the University of Pennsylvania and has over 35 peer-reviewed articles to his credit. He currently serves as a Professor of Biological Sciences at Lehigh University where his research involves delineation of design and natural selection in protein structures.

The Edge of Evolution’s purpose is to provide a “sober appraisal of what Darwinian processes can and cannot do.” It juxtaposes this objective against the notion that Darwinism is an all-or-nothing affair, where one must either accept the entire theory, or dump the baby with the bathwater. On Behe’s view, both avenues are mistaken. In fact, he highlights certain merits of Darwinian theory throughout the book and devotes an entire chapter to “What Darwinism Can Do.” Readers unfamiliar with Behe’s views will quickly learn that he affirms common descent, and also regards random mutation and natural selection as viable explanations of certain natural phenomena. His main thesis, however, concerns the limits of these central Darwinian mechanisms, which mustn’t be ignored in light of compelling scientific data.

To that end, Behe frames his argument within ten chapters which are accessibly-written for a popular audience. While some material is necessarily technical, a corresponding appendix provides a helpful primer, though the main points come through regardless of one’s mastery of the details. Similarly, chapter 1 (“The Elements of Darwinism”) provides sufficient background information with respect to the basic contours of Darwinism, while chapter 2 sets the stage for discussing evolutionary limits by contrasting competing Darwinian paradigms: “Arms Race or Trench Warfare.” The statistical components upon which Behe basis his conclusions receives thorough treatment in chapter 3, “The Mathematical Limits of Darwinism,” while chapters 4 and 5 survey “What Darwinism Can” and “Can’t Do,” respectively. Chapter 6 (“Benchmarks”) defines criteria by which to assess the proposed limits, while chapter 7 delves into their applicability to protein-binding processes. Behe uses chapter 7 to address possible objections to his argument, and then “crosses the edge” in chapters 9 and 10 to explore the implications of nonrandom mutation and the extent to which such considerations apply to the universe at large.

An inherent liability of any popular treatment which tackles technical matters, is the risk of losing an audience, either in a maze of technicalities or through sheer boredom; thus, to be effective, even persuasive data and sound reasoning must be made accessible and engaging. Thankfully for his readers, Behe hits the mark on both counts. Setting the argumentation aside for the moment, The Edge’s greatest strengths are its masterful and frequent use of analogy to illustrate abstract points, along with its appropriate wit and light-hearted humor, which make it truly enjoyable to read. With respect to analogy, it deserves mentioning that Behe is careful not to use it as anything more than a teaching device (i.e., he avoids arguing the analogy). Similarly, and also to his credit, he avoids other common informal fallacies such as attacking strawmen and ad hominems.

Of course, if The Edge was merely an enjoyable read at the expense of cogency, then it would rightly suffer a fate of ineffectiveness. But here again, Behe hits the mark—this time, by way of concrete examples based on credible research and sound mathematical reasoning. For example, he appeals to the work of Oxford malariologist, Nicholas White, in citing that resistance to the anti-malarial drug, chloroquine, requires approximately 10^20 replications of the malarial cell (a factor that Behe refers to as a “chloroquine complexity cluster,” or “CCC”)—a beneficial mutation (from the standpoint of malaria). He further reasons that a cluster which exhibits twice the complexity of CCC (a “double-CCC”) would require 10^40 replications to achieve a beneficial mutation, since the odds against two independent events is the multiple of the odds against each event. Finally, in light of University of Georgia research, which estimates that the entire number of cells throughout Earth’s history is just shy of 10^40, Behe observes that “we have no statistical right to expect that random mutation can include the changes that have been credited to it” beyond the threshold of a double-CCC—the tentative edge of evolution.

Behe also introduces criteria which prove helpful in distinguishing random from nonrandom mutation: steps and coherence. With regard to steps, he observes that if two mutations must occur before conferring a net benefit on an organism, then evolutionary explanations which appeal to merely random mutation encounter significant problems. By way of analogy, Behe invites readers to imagine a single missing step on a stairwell; though a couch potato could likely traverse the obstacle, a frail old man could not. He likens the couch potato in this scenario to malaria, given its ability to figuratively skip steps by virtue of its vast probabilistic resources (i.e., a population size of ~10^20); whereas the frail old man represents humans and large animals, whose population pales in comparison at ~10^9. Citing the observation of evolutionary biologists, Jerry Coyne and Allen Orr—that the goal of a theory is not to determine what is theoretically possible, but what is biologically reasonable—Behe concludes that random mutation is reasonable to a point, but suffers severe limitations when evolution must traverse multiple steps.

Of course, this brief review merely skims the surface of a few key points, though Behe’s insightful project merits a much closer look by readers interested in the possible limits of Darwinian evolution. To that end, The Edge of Evolution is highly recommended for anyone who appreciates an engaging and substantive treatment of a topic that has not only permeated the life sciences, but has overflown into many other aspects of contemporary thought. As mentioned, the style makes this work accessible to a diverse audience, including high school and college students who have perhaps accepted the notion that Darwinian evolution is an unassailable theory that defies all limits.

First, don't believe all of the negative reviews on this book. The majority of them are just "bashing". From reading the negative reviews it is obvious to me, having read the book, that many negative reviewers didn't actually read the book. Many were clearly personal attacks toward the author and most appeared to be written by angry teenagers or twenty year olds trying to portray themselves as sharp people of the scientific field. Intelligent people don't write negative reviews with that kind of style. Thankfully it is pretty easy to spot trolls that are bashing something that they don't understand.

This book has absolutely NOTHING to do with organized religion. It has absolutely NOTHING to do with disproving an evolutionary process. What it does do is list SCIENTIFIC FACTS that discredit a "Darwinian Evolution" which is driven by random chance. It does PROVE that a Darwinian process fails the scientific test. The book shows that Intelligent Processes from an Intelligent Source had to be in play for the development and advancement of life. Science is facilitated here, there is no hocus pocus involved.

Dr. Behe is a very intelligent person and also a very courageous one for going against the establishment. Armed with logic and more scientific understanding than most, he relays the most reasonable conclusion in the chance vs. intelligence argument. Scientific findings are only as good as their interpretations and Dr. Behe has clearly made the correct interpretations here.

Thank you very much Dr. Behe for having the courage for preserving logic when it isn't cool to practice it anymore.