Darwin Devolves

The New Science About DNA That Challenges Evolution

Michael J. Behe

• Publisher: HarperOne
• Year: 2019
• ISBN:
  9780062842688
• Topic: Biological Sciences
• Subtopic: Evolution
• Index: Biological Sciences

The scientist who has been dubbed the "Father of Intelligent Design" and author of the groundbreaking book Darwin's Black Box contends that recent scientific discoveries further disprove Darwinism and strengthen the case for an intelligent creator. In his controversial bestseller Darwin's Black Box, biochemist Michael Behe challenged Darwin's theory of evolution, arguing that science itself has proven that intelligent design is a better explanation for the origin of life. In Darwin Devolves, Behe advances his argument, presenting new research that offers a startling reconsideration of how Darwin's mechanism works, weakening the theory's validity even more.

A system of natural selection acting on random mutation, evolution can help make something look and act differently. But evolution never creates something organically. Behe contends that Darwinism actually works by a process of devolution—damaging cells in DNA in order to create something new at the lowest biological levels. This is important, he makes clear, because it shows the Darwinian process cannot explain the creation of life itself. "A process that so easily tears down sophisticated machinery is not one which will build complex, functional systems, " he writes.

In addition to disputing the methodology of Darwinism and how it conflicts with the concept of creation, Behe reveals that what makes Intelligent Design unique—and right—is that it acknowledges causation. Evolution proposes that organisms living today are descended with modification from organisms that lived in the distant past. But Intelligent Design goes a step further asking, what caused such astounding changes to take place? What is the reason or mechanism for evolution? For Behe, this is what makes Intelligent Design so important.

Part I

Problems

Chapter 1

The Pretense of Knowledge

The polar bear (Ursus maritimus) is the modern world’s largest land carnivore, but size and strength don’t ensure an easy life. The approximately twenty-five thousand animals are solitary creatures, except of course during mating season when they come together so females can birth an annual litter of one or two cubs. The bears endure dark, bitter winters and perpetually frigid ocean waters as they hunt a diet of chiefly seals. It is a difficult yet majestic role in nature, for which they are superbly adapted.

Ever since its classification as a separate species in 1774, it was realized that the polar bear is closely related to the almost equally huge brown bear (Ursus arctos). At first the polar bear was placed in a separate genus. But when it was discovered that the two species could mate successfully, they were both placed, together with the smaller North American black bear (Ursus americanus), in the genus Ursus. The earliest fossil of a polar bear is over one hundred thousand years old. The species is estimated to have branched off from the brown bear hundreds of thousands of years before that.

Although Charles Darwin didn’t mention them in his 1859 masterwork, On the Origin of Species, the polar bear is a wonderful illustration of his theory of evolution by random variation and natural selection. Like other examples Darwin did cite, the giant predator is clearly related to a species that occupies an adjacent geographical area, while just as clearly differing from it in a number of inherited traits. It is easy to envision how the polar bear’s ancestors might gradually have colonized and adapted to a new environment. Over many generations the lineage could have become lighter in color (making the bears less and less visible to their prey in snowy environments), more resistant to the cold, and more adapted to the sources of food in the Arctic, a process in which each step offered a survival advantage over the previous one.

Yet a pivotal question has lingered over the past century and a half: How exactly did that happen? What was going on within the bodies of the ancestors of the modern polar bear that allowed them to survive more effectively in an extreme climate? What was the genetic variation upon which natural selection was acting? Lying hidden deep within the genome of the animal, the answers to those questions were mysteries to both Darwin and subsequent generations of scientists. Only several years ago—only after laboratory techniques were invented that could reliably track changes in species at the level of genes and DNA—was the genetic heritage of the Arctic predator laid bare. The results have turned the idea of evolution topsy-turvy.

The polar bear’s most strongly selected mutations—and thus the most important for its survival—occurred in a gene dubbed APOB, which is involved in fat metabolism in mammals, including humans.¹ That itself is not surprising, since the diet of polar bears contains a very large proportion of fat (much higher than in the diet of brown bears) from seal blubber, so we might expect metabolic changes were needed to accommodate it.

But what precisely did the changes in polar bear APOB do to it compared to that of other mammals? When the same gene is mutated in humans or mice, studies show it frequently leads to high levels of cholesterol and heart disease. The scientists who studied the polar bear’s genome detected multiple mutations in APOB. Since few experiments can be done with grumpy polar bears, they analyzed the changes by computer. They determined that the mutations were very likely to be damaging—that is, likely to degrade or destroy the function of the protein that the gene codes for.

A second highly selected gene, LYST, is associated with pigmentation, and changes in it are probably responsible for the blanching of the ancestors’ brown fur. Computer analysis of the multiple mutations of the gene showed that they too were almost certainly damaging to its function. In fact, of all the mutations in the seventeen genes that were most highly selected, about half were predicted to damage the function of the respective coded proteins. Furthermore, since most altered genes bore several mutations, only three to six (depending on the method of estimation) out of seventeen genes were free of degrading changes.² Put differently, 65 to 83 percent of helpful, positively selected genes are estimated to have suffered at least one damaging mutation.

It seems, then, that the magnificent Ursus maritimus has adjusted to its harsh environment mainly by degrading genes that its ancestors already possessed. Despite its impressive abilities, rather than evolving, it has adapted predominantly by devolving. What that portends for our conception of evolution is the principal topic of this book.

The Future Starts Now

To understand the profound inadequacy of Darwinism, we must first understand evolution’s foundation. Molecules are the basis of physical life. DNA, the carrier of genetic information, is itself a molecule. In turn DNA encodes another class of very complex molecules, proteins, which can join together to form literal machines—molecular trucks, pumps, scanners, and more—that carry out the work of the cell. Among other duties, those machines build the structural materials of everyday life, such as shells, wood, flesh, and bones, which also are all made of particular molecules carefully arranged in particular ways. So in order to more fully understand life, one must understand its molecular basis. The study of the molecular basis of life is the task of my own field, biochemistry.³

Because molecules are the basis of life, they are also the basis of evolution. Mutations, the raw material for evolution, are changes in molecules—alterations of DNA and the proteins it codes for. For example, people with the sickle-cell gene have a simple change in their DNA that leads them to produce slightly altered hemoglobin and makes them resistant to malaria. People whose DNA has a small change in a gene dubbed OCA2 lose the ability to produce the molecular pigment melanin in their irises, turning their eyes blue. Most people who hear the word “evolution” probably think of fish with legs or dinosaurs with feathers. Yet they should think of proteins and DNA, because it is molecules that are the underpinnings of visible changes. To more fully understand evolution, one must understand its molecular basis, the biochemical level of life, which we’ll explore in subsequent chapters.

Through no fault of his own, Charles Darwin knew none of this. The science of the mid-nineteenth century was primitive compared to today’s. The very existence of molecules was still in doubt back then, and the cell, which we now know is filled with sophisticated molecular machinery, was thought to be made of a simple jelly called protoplasm. Perforce the Victorian naturalist was unaware of perhaps the central fact of biology: that heredity—a key prerequisite of his theory—is largely determined by an elaborate molecular code expressed through the intricate actions of hugely complex molecular machines. In the absence of such knowledge, Darwin hypothesized that hereditary traits were transmitted by nondescript theoretical particles he dubbed “gemmules,” which supposedly were shed by all parts of the body and somehow collected in the reproductive organs. Gemmules turned out to be wholly imaginary.

Although its components are often unwittingly conflated, Darwin’s theory of evolution is actually an amalgam of a handful of separate ideas, several of which do not depend as strongly as others on an understanding of biochemistry. For example, the ideas that life has changed over time and that organisms are related by common descent (both of which were controversial in Darwin’s time) are supported by evidence from geology, paleontology, and comparative anatomy. Those parts of his theory have withstood the test of time very well.

The situation is completely different for the parts of his theory that we now know do depend profoundly on the nature of the molecular level of life—in particular, for the crucial aspects that propose a mechanism for evolution. Those portions of Darwin’s theory that address the paramount question, “How in the world could such fantastic biological transformations possibly happen?” have for long years gone essentially untested, because research techniques that could probe the molecular level of life in the required detail were unavailable. Partly as a result, Darwin’s proposed mechanism of evolution is more widely questioned today than at any time since the role of DNA in life was discovered. To make up for what it is thought to lack, in the past few decades a number of scientists have proposed sundry alternatives to Darwin’s mechanism, such as neutral theory and natural genetic engineering. This book will advance a much different theory.

An understanding of the existing molecular basis of life is necessary for an evaluation of any proposed mechanism of evolution, but by itself is woefully insufficient. In addition to that knowledge, the many ways life can change at the molecular level also have to be understood—and then the frequencies of helpful ones must be measured and compared for a huge number of organisms over many generations. For all practical purposes that was impossible to do until very recently, when advanced laboratory equipment and new techniques became available to determine the exact DNA sequence of genomes and other critical molecular details. Only in the past few decades could the adequacy of Darwin’s proposed mechanism of evolution even begin to be tested.

To put a point on it, up until quite recently speculations on the topic by even the brightest minds were of no more account than were guesses about Earth’s place in the universe before the invention of the telescope. So forget what you’ve heard about how evolution happened. Only now do we have sufficient data to understand the causes of evolution.

Building a solid foundation for understanding that data does require some work. But it brings the substantial reward of a much better appreciation for the place of humanity, and indeed of all life, in the universe. At a minimum, we need a grasp of the outlines of the history of biology, the strengths and weaknesses of Darwin’s theory and modern extensions of it, the latest pertinent research results, and crucial philosophical topics. All of that this book will provide in a way that aims to be accessible to the general reading public. The book’s goal is to give readers the scientific and other information needed to confidently conclude for themselves that life was purposely designed.

So let’s delve right into it. Our first order of business is one of those crucial philosophical topics that’s indispensable for evaluating the relevant data: basic epistemological difficulties for Darwin’s theory. In other words, how do we know what we think we know about evolution? We’ll see compelling reasons to conclude that it is not nearly as well supported as it’s often portrayed to be.

Evolution and Economics

The study of evolution has a big economics problem. In his 1974 Nobel Prize lecture in economics Friedrich von Hayek decried the “pretense of knowledge.”⁴ Governments looked to economists for advice on policy questions, and they eagerly gave it. But in reality no one actually knew how to solve the rampant inflation of the time or other pressing problems. Intricate mathematical models were built that included what were thought to be the most important economic factors, but to little avail. Hayek lamented, “As a profession we [economists] have made a mess of things.”

The problem wasn’t that economists weren’t smart. The problem, thought Hayek, was physics envy. Physics envy is the always disappointed yearning by those in a thoroughly complex field to imitate those in a comparatively simple, wildly successful one. As difficult as physics seems to undergraduates, it deals mostly with inanimate matter and can focus on single variables in splendid isolation. Economics, on the other hand, must consider many interacting factors, including people. Economic results are affected not only by supply and demand, but also by competition, taxes, government regulations, technology, and more. They’re also influenced by noneconomic human factors such as culture, education, corruption, innovation, jealousy, ambition, disease, population density, greed, charity, and so on. It is effectively impossible to rigorously isolate one of the myriad influences for study away from all others.

So too for the study of evolution. As University of Chicago evolutionary biologist Jerry Coyne once said with a sigh: “In science’s pecking order, evolutionary biology lurks somewhere near the bottom, far closer to phrenology than to physics.”⁵ To be charitable, let’s just say closer to economics. Like economics, biology has to deal with, in Hayek’s phrase, “structures of essential complexity.” Yet the problem is very much worse for the study of evolution, because it concerns processes—many still largely unknown—that occur at the molecular level over thousands or millions of years, involving not only biological factors, but also geological, meteorological, and even celestial ones. Whatever considerations economic science has that confound the accuracy of its prognostications, evolutionary biology has those that affect its pronouncements with exponentially greater force.

Like economics, much of modern evol...