Design with a Purpose

Design with a Purpose

My back hurts this morning—another unwanted sign that my 50th birthday is rapidly approaching. And my eyesight—where are those reading glasses?

The human body is an amazing thing but, as I’m increasingly aware, it has its flaws. Some of the flaws in humans and all biological organisms are used as arguments against the divine design of life on Earth. After all, in Psalm 139, the Bible claims,

For you created my inmost being;
you knit me together in my mother’s womb.
I praise you because I am fearfully and wonderfully made;
your works are wonderful,
I know that full well.

Atheists like Richard Dawkins and the late Stephen Jay Gould claim that if God is so good and so smart, then he would have done a better job designing the world around us. Gould’s book The Panda’s Thumb1 criticizes the design of the panda’s thumb as a case of poor engineering. Meanwhile in The Blind Watchmaker, Dawkins takes issue with the design of the human eye.2 A quick search of the Internet will produce more examples of so-called “bad designs.” For many people, the God they envision would have done a better job at creation; therefore, God can’t be responsible for life as we see it.

As a designer of medical devices, I believe that critics like Dawkins use the wrong criteria to decide what is and is not a good design. Every engineer tends to criticize how another engineer solved a problem. By nature, we like to believe we could have done a better job. But many times it turns out we just didn’t understand the problem well enough to judge. It is interesting to see how many supposed examples of bad design in nature turn out to be better than we initially understood. The complexity of a problem takes time to understand because of the subtle interaction between the parts of a system.

The panda’s thumb and the human eye are prime examples of misunderstood designs. The more we study them, the more they exhibit good design. For example, the panda’s thumb doesn’t have the versatility and capability of the human thumb, but it works well for the repetitive motion of stripping bamboo leaves. The human thumb couldn’t take that kind of constant stress.3

As another example, the high density of rods and cones in the human eye requires an increased blood flow to the retina. This requirement means the neural connections must face outward, toward incoming light.4 We now know that the human eye elegantly compensates for the inverted retina with special cells that channel light past the neurons and down to the rods and cones.5 Some researchers theorize that the inverted retina provides better blood flow to the rods and cones and allows for better neural processing.6

Both of these examples should serve as a warning to avoid being hasty in declaring a design “bad” simply because it wasn’t engineered the way we think it should have been. (The fault for other supposed design flaws—like my need for glasses—rests more on corrupted manufacturing instructions than an actual flaw.) 

We must also keep in mind that all designs require tradeoffs. At the company where I work, when a client brings us an idea for a new or improved product, the first step is defining the specifications for the new device. For medical devices, this is an essential part of the FDA Design Control process. The exercise usually starts like writing a wish list for Santa. Our experienced clients know they can’t have it all, but figure why not aim high? Everyone wants the new device to be better than the competition. The product must be smaller yet have longer battery life and a bigger display, be lighter yet more rugged and durable, be simpler and easier to use yet include more features. And, of course, it should be cheaper, too.

It can be fun trying to achieve what seems impossible. In the end, however, you have to prioritize the most important features. The key is clear understanding of the goals. I’ve seen many development projects lose focus because the design team didn’t understand the real goals of their project. Too often, good engineering effort goes into achieving unnecessary features while crucial ones are missed.

Interestingly, the FDA regulations for verification and validation testing of medical products does not focus on determining if a device is “perfect” in some absolute way. Rather, they require (1) that the product’s physical and operational requirements are specified clearly; and (2) that the device is tested thoroughly to see that it truly meets those specifications. In essence, the regulations ask, “Are the goals clearly defined and does the device meet those intended goals?”

Going back to “bad” designs in nature, I believe the comparison with man-made engineering should change the scope and focus of how we view organisms’ functions and operations. We need to avoid looking at whether a particular biochemical process is as efficient as it could be (according to us) or at whether a particular organism is as well suited to its environment as it could be. Instead, we need to ask, “Does that organism or process fulfill its purpose in the overall system we call life on Earth?”

In my work, if the part I design fulfills its purpose, then it is considered a “good” part. Yes, another engineer might have made improvements irrelevant to the function of the whole device but that doesn’t make it better. For example, the “improved” part might be lighter but if weight doesn’t matter, then this change is not an improvement. 

In regards to God’s designs in nature, we need to look at the big picture. We no longer need to debate whether the panda’s thumb is optimally designed. We need to ask, “What was God’s purpose for the panda?” If the panda is fulfilling that purpose, then there should be no complaint about its thumb. Imagine a creature optimized according to our standards. That animal would most likely overrun its environment and unbalance the ecosystem.

Complete understanding of God’s design for individual creatures (or any physical phenomena) is difficult, if not impossible. But we can look at the history of life and see how different organisms in different places and times have resulted in a planet wonderfully suited for humanity.  The individual pieces may seem, to us, flawed and insignificant, but take a step back and even those “flaws” add to the beauty of the whole picture. (See Hugh Ross’ book Why the Universe Is the Way It Is, as well as his list of evidences for supernatural fine-tuning, for further discussion of the incredibly delicate balance required for terrestrial life.)

The Bible reveals much about God’s purpose for mankind. My favorite passage is Romans 8:18–19 where Paul writes, “I consider that our present sufferings are not worth comparing with the glory that will be revealed in us. The creation waits in eager expectation for the sons of God to be revealed.”

Thinking about what God has planned for our future helps me put the supposed imperfections of this world in perspective—even that nagging pain in my back.

by Brad Sargent, PhD 

  1. Stephen Jay Gould, The Panda’s Thumb: More Reflections in Natural History (New York: W.W. Norton & Company, Inc., 1980).
  2. Richard Dawkins, The Blind Watchmaker (New York: W.W. Norton & Company, Inc., 1986).
  3. Hideki Endo et al., “Role of the Giant Panda’s ‘Pseudo-Thumb,’” Nature 397 (January 28, 1999): 309–10.
  4. A. Wirth, G. Cavallacci, F. Genovesi-Ebert, “The Advantages of an Inverted Retina: A Physiological Approach to a Teleological Question,” Developments in Ophthalmology 9 (1984): 20–28.
  5. A. M. Labin and E. N. Ribak, “Retinal Glial Cells Enhance Human Vision Acuity,” Physical Review Letters 104, 158102 (April 16, 2010).
  6. L. M. Parver, C. Auker, and D. O. Carpenter, “Choroidal Blood Flow as a Heat Dissipating Mechanism in the Macula,” American Journal of Ophthalmology 89 (1980): 641–46.