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Intelligent Design Icon Intelligent Design

Complex Programmed Behaviors — Intelligently Designed

Eric Cassell
Photo credit: Eva Blue via Unsplash.

Editor’s note: The following is an excerpt from the newly released book, Animal Algorithms: Evolution and the Mysterious Origin of Ingenious Instincts, from Discovery Institute Press.

The fundamental claim of intelligent design is there are natural systems that cannot be adequately explained in terms of undirected natural forces and that exhibit features which in any other circumstance we would attribute to intelligence.1

William Dembski

Scientists typically specialize, and a biologist who does this may see problems for evolutionary theory in his or her own subdiscipline but then figure those problems are the exception and that evolutionary theory has things well in hand elsewhere in the life sciences. For this reason, it is vital to step back and take in the broader picture. Doing so reveals that while evolutionary theory nicely accounts for some things in the history of life, it runs into significant problems in many other areas. This should give us pause and encourages an objective consideration of how the theory of intelligent design holds up by comparison. Figure 7.1 summarizes such a comparison. A check mark indicates the theory or theories consistent with the observations related to the given category. The remainder of the chapter explains the basis for the comparisons.

 Metric     Blind Evolution     Intelligent Design
Similarities across taxaXX
Design flawsXX
Abrupt appearance X
Engineering design X
Genetic changes X
Origin of information X
Teleology X
Convergence X
Simple explanation X
Predictions and Retrodictions X
Figure 7.1. Comparison of discriminators for two proposed causes for the origin of complex programmed behaviors.

Discriminators that Don’t

Some discriminators don’t get us very far in deciding which is the better explanation between blind evolution and intelligent design. I’ve listed these first in the table and will discuss each of them only briefly here. 

The first listed is microevolution. One problem with the views of William Paley and other advocates of natural theology prior to Darwin is that they viewed the characteristics of organisms as fixed. Darwin demonstrated in The Originthat species were not immutable, but changed over time. A key element of Darwin’s evolutionary theory is adaptation. This may involve physical adaptation, such as brown bears evolving into polar bears in Arctic regions, or a strain of bacteria developing antibiotic resistance. And it may involve behavioral plasticity as organisms adapt their behavior to changing environments. Here the modern theory of intelligent design has more in common with evolutionary theory than with Paley, since the capacity of plants and animals to adapt to changing environments is understood as fully compatible with a design perspective; after all, an adaptable engineering design is superior to an inflexible one, all other things being equal. 

The Systems Biology Perspective

This, by the way, is a case where a systems biology perspective — regarding a biological system as an optimal or near-optimal engineered system for the purpose of studying and better understanding how it works — would lead one to expect and look for system features that enhance adaptability or, as we might say in a purely engineering context, robustness. (More on systems biology below.) Also, much microevolutionary change is devolutionary, and the design perspective has no difficulty with the idea that a design may show some degradation over time. Both perspectives account for the effect of genetic mutations. Even the best-engineered systems, after all, show wear and tear over time. So both modern Darwinism and intelligent design well accommodate microevolutionary change. The marvel is that there is so little biological devolution over time, thanks in no small part, we now know, to sophisticated DNA error-correcting mechanisms at the level of genes and proteins. 

What about similarities in functional traits (homology) across taxa, such as the recurrence of the pentadactyl (five digit) structure among various animals which is used for such diverse activities as grasping, climbing, crawling, and flying? Evolutionary theory does account for this. Darwin and his followers attribute such common features to inheritance from a common ancestor. At the same time, design also readily accounts for such similarities. Design theorists point to the reuse of successful design strategies in human-made designs, such as the reuse of pulleys, wheels, and gears in widely different technological contexts. (Convergence is a related issue that will be discussed below.)

Another feature of living things that evolutionary theory accounts for is design flaws (dysteleology) — the most obvious being disease and harmful mutations. These are to be expected from a mindless trial-and-error evolutionary process, it is argued. But the design paradigm also accommodates the presence of design flaws. The theory of intelligent design is not a theory of perfect design, and as noted above, even the best designs may degrade over time. 

Consider an Illustration

For example, if someone who had never encountered modern technology stumbled across a paved road, and in the next moment a man in a convertible Ferrari stopped and gave the primitive fellow a ride, the astonished rider would not be deterred from inferring that the car was the work of intelligent design just because the driver regaled his astonished passenger with the various ways his Ferrari was beginning to give him trouble — underbelly rust, burning too much oil, pulling to the right, etc. That the Ferrari was the product of creative intelligence would remain abundantly obvious to the passenger. In the same way any evidence of imperfect design in the biosphere cannot by itself negate whatever evidence for foresight and conscious design in biology does exist.

Moreover, and as discussed above, those working out of an evolutionary paradigm often are so primed to find bad design in biology that they find it where none exists — as for example in the case of “junk DNA” and so-called “vestigial organs” that turned out to have genuine functions. (More on the issue of imperfect design and dysteleology in Chapter 8.)

In addition to these, there are several other comparisons that can be made between Darwinian evolution and intelligent design. They include overall change over time and the progression from less complex to more complex species. Those issues have not been addressed in the book, but in any event they do not provide a discrimination in favor of either theory, since both models account for these patterns.

Next we move into discriminators that do weigh in favor of one explanation over the other. Taken together these make for a strongly positive case for design.


  1. William A. Dembski, The Design Revolution: Answering the Toughest Questions about Intelligent Design(Downers Grove, IL: InterVarsity Press, 2004), p. 27.