Darwinian evolution is being pushed to its limits by discoveries in biochemistry. Biochemistry is the study of the very basis of life: the molecules that make up cells and tissues, which catalyze the chemical reactions of digestion, photosynthesis, immunity, and more. Biochemistry includes all of the sciences that investigate life at the molecular level, even if the science is accomplished in a department with another name, such as molecular biology, genetics, or embryology.
The astonishing progress made by biochemistry since the mid-1950s is a tribute to science’s power to understand the world. It has brought many practical benefits in medicine and agriculture (and several potential horrors). Our knowledge may exact a price on our society because it seems to be advancing faster than our moral and legal system can handle.
When sciences such as physics finally discovered their basic foundations, old ways of understanding the world had to be reexamined, extensively revised, or restricted to a limited part of nature. Can this also happen to the theory of evolution by natural selection?
Darwin’s idea is very simple. He observed that there is variation in all species: some members are bigger, some smaller, some faster, some come have different colors, and so on. He reasoned that since limited food supplies could not support all organisms that are born, the ones whose chance variation gave them an advantage in the struggle for life would tend to survive and reproduce. The others would eventually be outcompeted for the necessities and fade away or die off. If the particular variation that occurred were to be passed on in the next reproduction cycle, then the characteristics of the species might change over time; over great periods, great changes supposedly could occur.
For about 150 years now, most scientists have thought that virtually all of life, or at least all of its most interesting features, resulted from natural selection working on random variation. Very little thought to how these interesting new features fit into the existing or changing environment better that the original ones did- but that was for later thinkers. Darwin’s idea has been used to explain finch beaks and horse hoofs, moth coloration and insect slaves, and the distribution of life around the globe and through the ages. There is nothing— no organ or idea, no sense or thought— that has not been the subject of evolutionary introspection.
Almost a century and a half after Darwin proposed his theory; evolutionary biology has had much success in accounting for patterns of life we see around us. For many, this triumph seems complete- the theory covers everything. However, the real work of life does not happen at the level of the whole animal or organ; it is difficult to see the most important parts of living things because they are too small. Life is lived in the details. The molecules actually handle life’s details.
Shortly after 1950 science advanced to the point where it could determine the shapes and properties of a few of the molecules that make up living organisms. Slowly, painstakingly, the structures of more and more biological molecules were discovered, and the way they work was inferred from countless experiments. The cumulative results showed with piercing clarity that life (what makes up you and me) is based on machines— machines made of molecules!
In short, highly sophisticated molecular machines control every cellular process. Thus the details of life are finely calibrated, and the machinery of life enormously complex.
Can all of life be fit into Darwin’s theory of evolution? Because the popular media likes to publish exciting stories, and because some scientists enjoy speculating about how far their discoveries might go, it has been difficult for the public to separate fact from conjecture. If you get your science knowledge from Bill Nye, Neil DeGrasse Tyson, Richard Dawkins, or Stephen Hawking, I feel for you. You are being taken on a fanciful ride to nowhere.
To find the real evidence you have to dig into the journals and books published by the scientific community itself. The scientific literature reports experiments firsthand and the reports are generally free of the flights of fancy that make their way into the spinoffs that follow. If you search the scientific literature on evolution, and if you focus your search on the question of how molecular machines— the basis of life— developed, you will find complete silence. The complexity of life’s foundation has paralyzed science’s attempt to account for it; molecular machines raise an as-yet-impenetrable barrier to Darwinism’s universal reach.
Evolution is a controversial topic, so it is necessary to address a few basic questions. Many people think that questioning Darwinian evolution must be equivalent to espousing creationism. As commonly understood, creationism involves belief in an earth formed only about ten thousand years ago, an interpretation of the Bible that is still very popular. I greatly respect the work of all the scientists (both secular and Biblical) who study the development and behavior of organisms within an evolutionary framework, and I think that evolutionary biologists have contributed enormously to our understanding of the world-although dated. Darwin’s mechanism— natural selection working on variation— might explain many things, however, it can in no way explain molecular life. I also do not think it surprising that the new science of the very small will change the way we view the less small.
When things are going smoothly in our lives most of us tend to think that the society we live in is “natural,” and that our ideas about the world are self-evidently true. It is hard to imagine how other people in other times and places lived as they did or why they believed the things they did. During periods of upheaval, however, when apparently ones well established beliefs (your verities) are questioned, it can seem as if nothing in the world makes sense. During those times, history can remind us that the search for reliable knowledge is a long, difficult process that has not yet reached an end. In order to develop a perspective from which we can view the idea of Darwinian evolution, I will very briefly outline the history of biology.
A Rube Goldberg contraption is a whimsical term for a device that does something, but whose inner workings are mysterious— sometimes because the workings cannot be seen, and sometimes because they just are not comprehensible. Computers are a good example of a contraption. We have no idea of how they work whether we are processing words or plotting graphs or playing games. We are in contented ignorance of what is going on underneath the outer case. Even if we were to remove the cover, there is no simple, observable connection between the parts of the computer and the things that it does.
In ancient times all of biology was a contraption, because no one understood on even the broadest level how living things worked. The ancients who gaped at a plant or animal and wondered just how the thing worked were in the presence of unfathomable technology. They were truly in the dark.
The earliest biological investigations began in the only way they could— with the naked eye. A number of books from about 400 B.C. (attributed to Hippocrates, the “father of medicine”) describe the symptoms of some common diseases and attribute sickness to diet and other physical causes, rather than to the work of the gods, which was a big improvement for theology. Although the books were a beginning, these pioneers were still lost when it came to the composition of living things. They believed that all matter contained four elements: earth, air, fire, and water. Living bodies were made of four “humors”— blood, yellow bile, black bile, and phlegm— and all disease supposedly arose from an excess of one of the humors.
The greatest biologist of the Greeks was also their greatest philosopher, Aristotle. Born when Hippocrates was still alive, Aristotle realized (unlike almost everyone before him) that knowledge of nature requires systematic observation. Through careful examination, he recognized an astounding amount of he recognized an astounding amount of within the living world, a crucial first step. Aristotle grouped animals into two general categories— those with blood, and those without— that correspond closely to the modern classifications of vertebrate and invertebrate. Even though his observations were unaided by instruments, much of Aristotle’s reasoning remains sound despite the knowledge gained in the thousands of years since he died.
Galen, a second-century A.D. physician in Rome. Galen’s work shows that careful observation of the outside and (with dissection) the inside of plants and animals, although necessary, is not sufficient to comprehend biology. Although he knew that the heart pumped blood, he could not tell just from looking that the blood circulated and returned to the heart. Galen mistakenly thought that blood was pumped out to “irrigate” the tissues, and that new blood was made continuously to resupply the heart. His idea was taught for nearly fifteen hundred years.
It was not until the seventeenth century that an Englishman, William Harvey, introduced the theory that blood flows continuously in one direction, making a complete circuit and returning to the heart. Harvey calculated that if the heart pumps out just two ounces of blood per beat, at 72 beats per minute, in one hour it would have pumped 540 pounds of blood— triple the weight of a man! Since making that much blood in so short a time is clearly impossible, the blood had to be reused. Harvey’s logical reasoning (aided by the still-new Arabic numerals, which made calculating easy) in support of an unobservable activity was unprecedented; it set the stage for modern biological thought.
In the Middle Ages the pace of scientific investigation quickened. The example set by Aristotle had been followed by increasing numbers of naturalists. Many plants were described by the early botanists Brunfels, Bock, Fuchs, and Valerius Cordus. Scientific illustration developed as Rondelet drew animal life in detail. The encyclopedists, such as Conrad Gesner, published large volumes summarizing all of biological knowledge. Linnaeus greatly extended Aristotle’s work of classification, inventing the categories of class, order, genus, and species. Studies of comparative biology showed many similarities between diverse branches of life, and the idea of common descent began to be discussed even though there was no particular reason for it.
Biology advanced rapidly in the seventeenth and eighteenth centuries as scientists combined Aristotle’s and Harvey’s examples of attentive observation and clever reasoning. Yet even the strictest attention and cleverest reasoning will take you only so far if important parts of a system aren’t visible. Although the human eye can resolve objects as small as one-tenth of a millimeter, a lot of the action in life occurs on a micro level, a Lilliputian scale. So biology reached a plateau: One black box, the gross structure of organisms, was opened only to reveal the black box of the finer levels of life. In order to proceed further biology, needed a series of technological breakthroughs. The first was the microscope.
That was the death knell for all things Darwin. Neal DeGrasse Tyson, Richard Dawkins, and the rest of their ilk, are out of the running. Everything you say is moot, there is no proof but that which we can see at the microscopic level. Moreover, that does not randomly develop in 6.5 million species of plants and animals at or near the same time.
Till next time LEM