“Intelligent design” creationists often claim that evolution could not have produced the living things that inhabit Earth because, they say, certain biological structures are “too complex” to have arisen through the action of an unguided survival-of-the-fittest natural selection process applied to individual variations caused by random mutations. Let us examine that claim.
The word “too” implies that a comparison is being made. In order to evaluate that comparison, we need to know what kind of a comparison it is, and what is being compared to what.
Use of a tape measure shows that my office doorway is 29 inches wide and my desk is 30 inches wide. By comparing these numerical measurements, I can say that my desk is “too wide” to go through my office doorway in the upright orientation. This is an example of an objective comparison. The result depends only on the objects being compared. The result will be the same if a different person makes the measurements or if the measurements are made in centimeters rather than inches.
The other type of comparison is subjective. In a subjective comparison, the result depends on the thinking subject who is making the comparison. For example, someone might state that a bowl of chili is “too spicy” for his or her taste. This person is comparing his or her perception of the spice content of the chili to his or her preferred level of taste stimulation. The result of this kind of comparison depends mainly on the subject who is making the comparison. Chili that is “too spicy” for the example person mentioned above might not be “too spicy” for me. I happen to like my chili spicy -- up to a point. Chili that’s spicy enough to be used for stripping paint would probably send ME running for a water faucet.
Getting back to the main event, we first need to determine whether the “too complex” claim is based on an objective or subjective comparison. Since I have yet to hear of any “intelligent design” creationists giving specific details about how their “too complex” conclusion was reached, it’s not obvious which category their comparison falls into. Let’s start by assuming that the comparison is objective. That means that there must be some objective way to measure “complexity,” and some objective standard to which that measurement can be compared.
In biological terms, an organism that most people would judge to be “more complex” than another would probably be seen to have a more intricate structure.
As anyone who has had experience with products labeled “some assembly required” knows, the more intricate an object is, the more information is needed in order to assemble it. Biological information is stored in an organism’s DNA, so an organism that has a more intricate structure will probably need more DNA to encode the instructions for assembling that structure.
Judging information content by a measurement of DNA length requires awareness that most organisms’ DNA is still incompletely understood, and that the stretches currently labeled “junk DNA” may indeed be junk. Nevertheless, since the genomes of many organisms seem to contain at least some “junk DNA,” its contribution to DNA length may not prove to be a confounding factor. DNA length is probably a pretty good proxy to use for making an objective measurement of an organism’s “complexity.”
If the length of a mutating organism’s DNA is to have any influence over whether or not the organism is capable of becoming more “complex” through an unguided natural selection process, there needs to be:
- A natural, biological mechanism for making that measurement of the length of DNA that the mutating organism has accumulated.
- A natural, biological standard that specifies a maximum possible length of DNA.
- A natural, biological mechanism that is capable of comparing the measured length of DNA to the maximum-length standard and stopping the accumulation of DNA at that point -- forcing the organism to wait for the guiding hand of an “intelligent designer” to add more DNA, thus giving it further instructions for becoming more “complex.”
To the best of my knowledge, no such natural mechanisms have ever been discovered in any living organism. Natural processes do not exhibit any mechanism that is capable of placing a limit on the length of DNA that a mutating organism can accumulate. One might argue that such a limit could be imposed artificially by an “intelligent designer,” but no such interference with the natural, chemical activity of DNA has ever been observed. Since any such interference would be acting upon structures made of ordinary matter and energy, the mechanism of any such interference should be detectable with instruments made of ordinary matter and energy.
Given this failure of the “too complex” claim to meet the requirements necessary for being deemed an objective comparison, we must conclude that the “too complex” claim is reached by a subjective process, whereby the thinking subject compares the observed “complexity” of organisms to his or her own personal estimation of the amount of complexity that an unguided natural selection process “should” be capable of producing.
This brings up the question of how a person develops his or her estimation of the amount of complexity that an unguided natural selection process “should” be capable of producing.
“Intelligent design” creationists appear to have simply accepted the creation stories that were concocted in pre-scientific times to explain the world. In this pre-scientific concept of reality, anything that happens happens only because it is made to happen by the conscious effort of a human or a god, and any event that humans are not capable of causing is attributed to the act of one or more gods. Based on nothing more than someone’s unsupported claim of “revealed knowledge,” people were led to believe that the Sun rises, the wind blows, the rain falls, or not, and the Earth trembles or belches fire all because one or more gods will it. This worldview apparently leads “intelligent design” creationists to estimate that any process which is not guided by a conscious entity can produce only chaos.
Creationists assert that there has to be a god-like creator simply because no other possible explanation had been devised back when their creation stories were concocted, and their worldview has not kept up with the discoveries of science. Even today, one of the most frequently-heard arguments supporting creationism is “Well, then, if a god didn’t do it, how did all of this get here?” That argument invokes no positive evidence that would tend to back the claim that an “intelligent designer” exists. It is an attempt to use a negative, ignorance-based argument as evidence, but ignorance is not evidence. This attempt at using ignorance as evidence is a sign that the only “evidence” for “intelligent design” creationism is creationists’ own inability to comprehend how life might have developed without the conscious effort of a “creator.”
Another argument that creationists use to dispute evolution is the claim that “macro evolution” is impossible because chimpanzees don’t give birth to humans. This indicates that the speaker lacks even the most basic knowledge of evolution, and probably believes, contrary to the evidence, that the Earth is a mere 6000 years old. In the short term, each species does indeed reproduce “according to its own kind,” but over tens to hundreds of thousands of generations, “kind” changes. That is “macro” evolution.
Everyone knows that the individuals of any species are not all identical. They vary in size, strength, speed, acuity of the senses, ability to find food, avoid predators, fight off diseases, and so on. As a location’s environment changes with the ice-age/interglacial cycle, continental drift, ocean circulation changes, and so on, some variants that were marginally suited to the previous environment will become advantageous. Other variants will become disadvantageous. The former will enjoy greater survival and reproductive success; the latter may perish without reproducing. That is “survival of the fittest.” As environmental change and adaptation to that change go on for tens of thousands of generations, the outward form of the species -- its “kind” -- will slowly morph as newly advantageous traits become more common, and disadvantageous traits become less common.
The main reason why we’ve never seen something like an antelope morph into a giraffe, or an archaic primate morph into a human, is the timescale. For mammals that reproduce with five to ten year generation times, it takes fifty thousand to a hundred thousand years to produce ten thousand generations.
Under favorable conditions, bacteria reproduce in 20 minutes or less. That short generation time gives 26,300 generations per year, 2 million generations since penicillin came into use in 1945 years ago. With all the trillions of individual bacteria produced in every generation, multiplied by that many generations, it’s no surprise that several bacterial species have evolved -- and continue to evolve -- resistance to more and more antibiotics, on a timescale that we can observe over a single human lifetime. That, too, is “macro” evolution.
Finally, I have a question for those who believe that “macro” evolutionary processes have not had time to have taken place because they believe that the Earth is a mere 6000 years old. How is it that we know enough about radioactive decay processes to create everything from radium-dial wristwatches to nuclear weapons, but suddenly cannot trust that knowledge when we use it to determine the age of biological specimens and geological layers by analyzing their carbon-14, potassium-40 or uranium-to-lead decay progress?