Saturday, April 10, 2010

Bad/Odd Design

Coyne cites “bad design” as an argument against creationism. Vestigial organs are one example of bad design like our appendix. Coyne also gives examples of odd design that shouldn’t be created by an intelligent designer. One example of this is the flatfish; as opposed to other fish, the flatfish swims on its side and has deformed features. (82)

Find an example(s) of bad design in organisms, like in the flatfish, and describe the functions of traits/structures and give a possible evolutionary basis for that trait. Explain why bad design is evidence of evolution and also write why creationists are so keen to avoid the topic of bad design.


  1. Coyne mentions many times throughout Why Evolution is true that "bad design" is evidence for evolution. There are two parts that must first be established. First, there must be evidence of "bad design" in varying species and traits. Second, there must be an evolutionary perspective that must explain why the bad design would prove to be an argument against creationism.
    For examples of bad design, Coyne mentions many examples such as dead genes that are no longer used, flatfish crushing one side of their body to become flat, and the laryngeal nerve that goes under the heart instead of directly to the larynx. Outside of his book, there are many more examples of bad design. Examples would include the human esophagus (using the same tube for breathing and eating causes choking, and sometimes death), the human eye (putting the optical nerves in the back of the eye), and the useless eyes in cave dwelling salamanders (which can be easily damaged) offers even stronger evidence for evolution because of their possible usefulness in their ancestors.
    But how does "Bad Design" disprove Intelligent Design and further supports Evolution? First, many of these designs simply don't make sense--why would an "intelligent" designer make pointless limbs, choking hazards, and easily damageable blind eyes? The most common reply may be "God works in mysterious ways", or "God can take away what he gives", but notice my previous emphasis on "intelligent". Intelligent design also lacks support for how these animals came into being, why they were that way, and why they were made to be beneficial/harmful. In an evolutionary perspective, helpful traits are passed on, and some vestigial parts are left and are sometimes impossible to get rid of. For example, humans may never be able to get rid of the appendix forever due to if it got any smaller, it would be even more likely to get infected, and also would lead that variation in population less likely to survive, and thus, less likely to pass along those genes. In the light of these examples, only evolutionary adaptation can fully and logically explain how any why many of these traits are present within animals as well as ourselves.

    Biology Book
    Why Evolution is True

  2. One organism that has bad design would be the Cassowary. It has the useless wings that Coyne talks about a lot. Why would an intelligent designer give an animal such a structure that proves to be completely useless. Though Coyne point out that these animals could use their wings in order to balance. Though could it be possible that these wings are in the process of being "dissolved?" Sorry for my use of language, but what i mean is that in time from now could it disappear? Could natural selection, maybe in time give them any possible use for these wings? Evolution shows that certain traits appear and disappear throughout the generations. We don't know but these wings maybe do serve some purpose. They could be used also for frightening away predators.
    Bad design is evidence for evolution because exactly what Tianyu said, "Why would a designer put pointless wings, etc on a creature?" It provides them no advantage. It in tern could harm their survival, like the human appendix. It is there as an annoyance to us knowing that it could possible kill us. An intelligent designer would not put thoughtless organs on or in a creature. Creationist have been keen on this topic because there is no way to prove that they are right. The only way is to find fossils that show that these organs were once in use. Wait, fossils can't show us this evidence. They would need to wait to see in the future if any organs could possibly come to use. Like i said, the wings on the bird could possibly be in the process of being removed, or they could in the future, through natural selection, be given a use.


    Tianyu's comment

  3. An example of bad design would deal with female reproduction. Many know that birth is a painful process, but why it’s painful is because of the pelvis. Without using spinal anaesthesia or other pain relievers given to woman in labor at hospitals, woman used to die during labor as well as their babies. The pelvis is too narrow for our big evolved brains, but that is in exchange for being able to walk upright. Obviously trying to move something large through a small area isn’t exactly great design, and it would have been better to have rerouted the reproductive tract in order for there to be a bigger gap. A female reproduction organ that also has bad design is the gap between the ovaries and the fallopian tube, where eggs travel through before implanting in the uterus. The reason these small gap is such an issue is because occasionally implants abdominally instead of in the uterus. This causes a whole line of complications including “risk of hemorrhage, disseminated intravascular coagulation, bowel obstruction, and fistulae.” (Medscape). Without surgery it is fatal. Why were the female reproductive organs given such a bad design? According to Coyne, “the gap is a remnant of our fish and reptilian ancestors, who shed eggs directly from the ovary to the outside of their body” (85). In this case, those ancestors wouldn’t have to worry about the egg implanting and developing inside of them.

    Creationists are prone to avoiding the topic of bad design as it wouldn’t make sense why a great designer would make organisms with unfavorable characteristics. Why make birth more painful or potential fatal if not taken care of medically? A creationist might say it’s because a great designer wouldn’t want to make us perfect. As the book Coyne site’s in his own, a great designer could have done it for “artistic” purposes or because they have “as-yet-detectable practical use” ( 85). As talked about in the previous paragraph, it is a support of evolution because it shows how we still have traits from ancestors that never adjusted over time.

    The Book

  4. One example of bad design is in the human esophagus. Ideally, when one swallows, a flap of cartilage called the epiglottis is supposed to close and cover the opening to the trachea so that food does not enter it and reach the lungs. The only problem is that this does not always work and can result in choking. This led to the suggestion that a better design would have been to have two separate tubes where one leads from the nose to the lungs and the other from the mouth to the stomach.

    After translation, pre-mRNA is modified through RNA splicing. During alternative splicing, large portions of extra nonfunctional nucleic acid, called introns, are cut out and it seemed that the cell did not have any use for them. This is why many scientists believed that introns were “junk” DNA, absolutely purposeless. Recently, this view has changed. Now scientist believe that introns play an important role in RNA splicing by determining which genes should be expressed. This shows that although something may seem useless, there is still a lot that scientists do not know that can prove otherwise.

    According to Britannica Online, creationists believe that God created various forms of life out of nothing. They also believe that God created everything perfect in his image. Therefore, creationists avoid examples of bad design. If God created us perfect, we would not have useless body parts like appendixes or created a imperfect system for breathing and eating. Why would He try to put us in situations that would harm us? “Bad design” disproves their beliefs, and most creationists were probably relieved to hear that introns most likely do have a purpose. This would allow them to say that everything has a purpose, even if we don’t realize it yet.

    Campbell book pages: 334, 885

  5. As Tianyu and Andrew said earlier, bad design is a result of evolution because an intelligent creator would never design an imperfect way of accomplishing something. Evolution creates imperfect designs because, as Coyne says, "new parts evolve from old ones, and have to work well with the parts that have already evolved. Because of this, we should expect compromises: some features that work pretty well, but not as well as they might" (81). The limited adaptations that evolution can produce are because of the nature of natural selection: every trait that get passed on must give an organism some advantage to survive and reproduce over others ( However, the design of some organisms would require taking "a step that reduces fitness" (84). Evolution makes it impossible for a species to take one step backwards, even if it would result in a more well-designed organism later on.This is called historical constraint.
    There are many examples of bad design in animals today besides the ones already mentioned. For example, in the African locust, the nerve cells connecting to the wings are located in the abdomen, despite the wings being in the thorax. This design makes the nerves longer than necessary, much like the laryngeal nerve in humans ( Another example of bad design could be observed in pandas. A panda's hand has 6 digits, with 5 digits curling around normally and a "thumb" being opposable. This last digit is a created by enlarged bones that are located in the wrists of other species. This sixth digit does allow a panda to grasp bamboo more easily, but it is an example of imperfect design created by evolution ( Many more examples of "bad design" can be found at:

    Intelligent design supporters most likely avoid the topic of bad design because they don't have an explanation for it. Coyne questions many times in his book why a creator would ever make an imperfect design for an organism. This is a very good point, because if natural selection and evolution wasn't the engine that drove species to live, an imperfect species would be doomed to become extinct without the help of natural selection.