Two Reasons Darwinism Survives
I have always considered Darwin's attempt to explain all of the apparent and obvious design in biology, and even human consciousness and intelligence, in terms of the accumulation of useful accidents to be the dumbest idea ever taken seriously by science. As scientific research continues to reveal the astonishing dimensions of the complexity of life, especially at the microscopic level, how does such a theory persist?
I believe there are two main reasons why this extremely implausible theory continues to enjoy such widespread popularity, despite the absence of any direct evidence that natural selection can account for anything other than very minor adaptations. Neither specifically supports Darwinism, only naturalism, but since all alternative naturalistic theories are even more far-fetched than Darwinism, they are considered to be indirectly supportive.
First, in every other field of science, naturalism has been spectacularly successful; why should evolutionary biology be so different? Is it really possible that science, after successfully explaining so many other phenomena in nature in terms of unintelligent laws, would hit a brick wall in evolutionary biology, and have to appeal to "design" here for the first time? Count this as a point in favor of naturalism, and against design, but it is fundamentally a philosophical point, not a scientific one. But until quantum mechanics, science never had to recognize that some things in nature are, in principle, impossible to predict. Until the Big Bang theory, which pointed for the first time to a beginning in time, scientists had always believed that, as geologist Joseph Le Conte put it, "each state or condition grew naturally out of the immediately preceding." So, yes, of course it is possible that evolutionary biology could be different, why not? And my 2013 Bio-Complexity article "Entropy and Evolution" explains why it is so different that it requires a different type of explanation.
Second, there are many things about the history of life that give the impression of natural causes. The argument is basically, "This doesn't look like the way God would have created things," an argument used frequently by Darwin in Origin of Species.
But in fact, as I pointed out in a 2000 Mathematical Intelligencer paper, "A Mathematician's View of Evolution," although the history of life may not give the appearance of creation by magic wand, it does look very much the way we humans create things, through testing and improvements. Harvard paleontologist George Gaylord Simpson summarizes the fossil record as follows:
It is a feature of the known fossil record that most taxa appear abruptly. They are not, as a rule, led up to by a sequence of almost imperceptibly changing forerunners such as Darwin believed should be usual in evolution...This phenomenon becomes more universal and more intense as the hierarchy of categories is ascended. Gaps among known species are sporadic and often small. Gaps among known orders, classes and phyla are systematic and almost always large. These peculiarities of the record pose one of the most important theoretical problems in the whole history of life: Is the sudden appearance of higher categories a phenomenon of evolution or of the record only, due to sampling bias and other inadequacies?
If archaeologists of some future society were to unearth the many versions of my PDE solver, PDE2D, that I have produced over the last thirty years, they would certainly note a steady increase in complexity over time, and they would see many obvious similarities between each new version and the previous one. In the beginning it was only able to solve a single linear, steady-state, 2D equation in a polygonal region. Since then, PDE2D has developed many new abilities: it now solves nonlinear problems, time-dependent and eigenvalue problems, systems of simultaneous equations, and it now handles general curved 2D regions, and has adapted to 1D and 3D problems. An archaeologist attempting to explain the evolution of this computer program in terms of many tiny improvements might be puzzled to find that each of these major advances (new classes or phyla??) appeared suddenly in new versions; for example, the ability to solve 3D problems first appeared in version 4.0. Less major improvements (new families or orders??) appeared suddenly in new subversions, for example, the ability to solve 3D problems with periodic boundary conditions first appeared in version 5.6. In fact, the record of PDE2D's development would be similar to the fossil record, with large gaps where major new features appeared, and smaller gaps where minor ones appeared. That is because the multitude of intermediate programs between versions or subversions which the archaeologist might expect to find never existed because -- for example -- none of the changes I made for edition 4.0 made any sense, or provided PDE2D any advantage whatever in solving 3D problems (or anything else) until hundreds of lines had been added. Just as major advances in the development of a computer program cannot be made though a chain of five- or six-character improvements, no major evolutionary advance is reducible to a chain of tiny improvements, each small enough to be bridged by a single random mutation.
We see this same pattern in the development of other technologies. If some future paleontologist were to unearth two species of Volkswagens, he might find it plausible that one evolved gradually from the other. He might find the lack of gradual transitions between automobile families more problematic, for example, in the transition from mechanical to hydraulic brake systems, or from manual to automatic transmissions, or from steam engines to internal combustion engines; though if he thought about what gradual transitions would look like, he would understand why they didn't exist. He would be even more puzzled by the huge differences between the bicycle and motor vehicle phyla, or between the boat and airplane phyla. But heaven help us when he uncovers motorcycles and Hovercraft. The discovery of these "missing links" would be hailed in all newspapers as final proof that all forms of transportation arose gradually from a common ancestor, without design.
The similarities between the history of life and the history of technology go even deeper. Although the similarities between species in the same branch of the evolutionary "tree" may suggest common descent, similarities (even genetic similarities) also frequently arise independently in distant branches, where they cannot be explained by common descent. For example, according to a Nature Encyclopedia of Life Sciences article, "Carnivory in plants must have arisen several times independently of each other... the pitchers might have arisen seven times separately, adhesive traps at least four times, snap traps two times and suction traps possibly also two times." This phenomenon, known as "convergence," suggests common design rather than common descent: the probability of similar designs arising independently through random processes is very small, but a designer could, of course, take a good design and apply it several times in different places, to unrelated species. Convergence is a phenomenon often seen in the development of human technology, for example, Ford automobiles and Boeing jets may simultaneously evolve similar new GPS systems.
Ken Miller challenged critics of Darwinism to explain why, in the fossil record, we find "one organism after another in places and in sequences...that clearly give the appearance of evolution." I responded, in this ENV article, with another question: "Why does the history of technology give the appearance of evolution, when it was really the result of intelligent design?"
So if the history of life looks like the way humans, the only other known intelligent beings in the universe, design things -- through careful planning, testing and improvements -- why is that an argument against design? Like many other arguments used by Darwin and Darwinists, this argument is fundamentally a religious argument, involving assumptions about how God ought to have created things: He should have used a magic wand.
Darwinism owes its popularity entirely to these two philosophical and religious arguments; as a scientific theory it has nothing else to recommend it.