I think of myself as one of the many victims of the idea of unguided atheistic evolution. Why? When I was a child, the medical establishment bought into the notion that there were many “useless” parts of the human body. If science couldn’t determine a function, many learned people thought this meant that there was no function. This kind of reasoning led my parents to have my tonsils removed on the advice of the family doctor.
Aside from padding the retirement fund of the family physician, this operation has had the effect of making me extremely susceptible to sore throats my entire life. As we now know, tonsils serve a useful purpose in the immune system by being what we might call an “early warning system”. When the tonsils get infected, the immune system responds preventing the infection from spreading to other parts of the body. To look on the bright side, the medical establishment used to think that human beings only used 10% of the human brain. At least they didn’t give me a lobotomy!
In a previous post, I said that when I looked at life around us I came to the conclusion that the process of evolution is a guided process. How do we tell the difference between guided and unguided evolution? One way is to examine what is called the argument from imperfection. If life is filled with useless artifacts of a historical process of development, then evolution looks unguided. If, on the other hand, most of the “useless” artifacts of advanced life still perform vital functions, then this suggests a guided process. Let us consider some examples of the argument from imperfection.
The Coccyx (or Tailbone)
When I first became a Christian, two features of modern humans made faith in God’s creation extremely difficult. Wisdom teeth don’t seem to have any real purpose for modern industrial humans, but the idea that they are historical artifacts of ancestors that had larger jaws makes a good deal of sense. Likewise, the tailbone seems for all the world like it is a residual structure left over from arboreal ancestors. If God created human beings why would we have wisdom teeth and the coccyx?
While I still don’t know of any useful function for wisdom teeth, I did discover a useful function for the coccyx the hard way. It happened one night while I was leaving a movie theater. I slipped on some ice while going down the stairs and fell hard right on my behind. Going to the hospital, I found out that my coccyx was shattered and I ended up having to spend 3 months sitting on an inflatable donut. Where would all of the energy that shattered my coccyx have gone if I did not have a coccyx? There is only one place where it could have gone: the base of my spine. Now I am no doctor, but this seems like it could have been very bad. Since falling on our behinds is not all that rare among human beings, my experience suggests that the coccyx serves the useful purpose of a shock absorber.
Stephen Jay Gould once argued that the Panda’s thumb was extremely powerful evidence for an unguided process of evolution. This is because what appears to be a human-like thumb is really fused together in such a way as to make it immovable. Since human thumbs are so important and useful, this seemed to Dr. Gould to be an obvious imperfection.
Once again, however, my experience prevents me from jumping on the “obvious imperfection” bandwagon. As I type this out, I am using a “wave” keyboard. I love “wave” keyboards and whenever mine wears out I run out and buy another one as soon as possible. Why? Because as a programmer who types all day, I have had an experience with tendonitis and the idea of using a standard keyboard is unthinkable to me. What does this have to do with the Panda’s Thumb? Only that it seems to me that an animal that uses its thumb to strip bamboo all day long would gain a survival benefit from a thumb that was not prone to tendonitis.
Rabbits digestive system
In a PBS special entitled, “In the Beginning” Professor of Paleontology
at the Carnegie Museum of Natural History Leonard Kristalka cited the rabbit’s
digestive system as an example of imperfection in nature. Evidently, rabbits only metabolize a small fraction (10%?) of the energy in the food that they consume. This, he argued, was an example of imperfection in nature that clearly pointed to an unguided evolutionary process. Though it may seem like evidence of an unguided process to Dr. Kristalka, the rabbit’s digestive system seems like much more powerful evidence of a guided process of evolution to me.
Because the rabbit’s digestive system is inefficient, rabbits leave nutrient rich feces wherever they roam. If other creatures in an ecosystem use rabbit feces as fertilizer (plants) or as a breeding ground (certain insects), then rabbit feces might serve a useful role in the ecology. An unguided process could never create a rabbit with an inefficient digestive system for this ecological purpose, but a guided evolutionary process could.
A second possible ecological benefit of a rabbit with an inefficient digestive system is suggested by looking at the problem in Australia. Without efficient predation, rabbits in Australia were an ecological disaster. Rabbits with an inefficient digestive system are much more prone to predation than rabbits with an efficient digestive system would be. This is because rabbits with a bad digestive system will have to eat more food than rabbits with a good digestive system. More food at the same rate of intake means more time spent foraging for food. More time spent foraging for food means more time exposed to predators. If a stable ecology requires a fast breeding herbivore at the bottom of the food chain, a guided process of evolution might result in such a creature having a digestive system with a low efficiency. An unguided process of evolution would optimize the rabbits’ digestive system for the benefit of the species and not for the benefit of the ecosystem as a whole.
The most powerful evidence for an unguided process of evolution has always been the fact that a good fraction of the genomes of advanced life forms was filled with what seemed to be useless detritus. Recent discoveries from the ENCODE project have greatly weakened this argument suggesting that as much as 80% of the unused sections of the human genome perform regulatory functions. This is a devastating blow to the case for unguided evolution and the history of arguments from imperfection suggests that more functions will be found for the “useless” portions of the genome as our knowledge advances.
The Difficulty of Concluding Imperfection
As we can see by looking at the examples of “obvious imperfection” that have been used to advance the notion of unguided evolution discussed above, concluding that an organ or a structure is “imperfect”or useless is extremely difficult. In order to be considered truly “useless” or imperfect, an organ or structure must be shown:
- To be useless at every stage of human development. The belly button, for example, is clearly useless, but it is an artifact of the umbilical cord which had an extremely vital function.
- To be useless in every extreme of environment and lifestyle. Adaptations which are useful for Eskimos may be useless for desert dwellers but they are not useless to the species as a whole.
- To be useless in every emergency situation. Using an analogy to the “knockout studies” used by biologists, an engineer from another culture might conclude that buildings in California had many “useless” structural supports. Only a person who was familiar with the region’s seismic activity would know that these structures were not useless at all but highly necessary.
Given the limitations of human understanding of complex biological systems, concluding that various structures or organs are “useless” is highly problematic and the history of biology is full of examples where greater understanding invalidated previously accepted conclusions of lack of function.
One of the consequences of evolution is common ancestry and the imperfections that must arise from a process of development that is subject to the forces of randomness over long periods of time. Because the evidence for common ancestry and vestigial organs is very strong, I do not deny that there are many organs and structures that have little or no use for modern organisms. On the other hand, examining various examples of imperfection from a skeptical perspective strengthens the impression of divine guidance and suggests another force operating alongside those of time and chance.
I have seen something else under the sun: The race is not to the swift or the battle to the strong, nor does food come to the wise or wealth to the brilliant or favor to the learned; but time and chance happen to them all. (Ecclesiastes 9:11)