|This article or section possibly contains previously unpublished synthesis of published material that conveys ideas not attributable to the original sources. (January 2014)|
||It has been suggested that this article be merged into Argument from poor design. (Discuss) Proposed since November 2013.|
Unintelligent design is a trait inherited through natural selection that is detrimental to the organism. Although evolution through natural selection generally provides organisms with adaptations that benefit its success, there are some traits that are derived from evolution that are not to the benefit of the organism. These traits are not necessarily selected for in the organism because they certainly do not provide advantages over others. These traits were part of an organism that had different traits that made it successful, and through the process of natural selection, these organisms that succeeded due to other traits passed along their ineffective traits to other organisms in the evolutionary chain.
Examples in humans
One example in humans of unintelligent design is the eyes. The eyes perceive images by receiving light in the retina. The retina sends electrical signals to the brain through the optic nerve and people see images. The optic nerve, however, is connected to the retina on the side that receives light, essentially blocking a portion of the eye and giving humans a blind spot. A better structure for the eye would be to have the optic nerve connected to the side of the retina that does not receive the light, such as in cephalopods.
Another example in humans is the throat. The esophagus, the part of the throat that allows food to travel to the digestive tract, is connected to the pharynx and the larynx, the parts of the throat that allow humans to breathe and talk. Because these parts are connected, choking can become a major issue. Food and other objects can sometimes get stuck in the throat blocking the air flow and not allowing much needed oxygen to enter the lungs and the rest of the body. If the parts were not connected and did not share a portion of their travel paths, choking would not be an issue, as it isn’t for most other animals in the world.
The teeth present a third example in humans alone of unintelligent design. When human beings first started developing larger brains, they had to evolve larger skulls to be able to store the larger brain. Evolution caused the skull cavity to become larger by adding bone from the jaw. In essence, the jaw became smaller to support a larger brain, but the teeth that were in the jaw did not become smaller in size. The amount of teeth that used to fit in the human mouth no longer fits. Because humans generally don’t have room for all 32 teeth, problems arise when all 32 teeth grow in. Wisdom teeth are generally the most problematic due a smaller jaw size. Wisdom teeth, when growing into a jaw that no longer has room, can damage neighboring teeth or even cause serious infections of the mouth. If the human jaw was larger in size there would be plenty of room inside the mouth for all 32 teeth to be present at the same time and the problems that are persistent with wisdom teeth would be less of a threat.
Another issue that evolved from having a larger brain is that parts of the human body cannot heal properly. The spinal cord, for instance, cannot ever properly heal if it is damaged. Because neurons have become so specialized through evolution, they are no longer able to regrow once they reach their mature state. If the spinal cord is injured, even slightly bruised, the neurons cannot repair themselves like other body cells can. The spinal cord, if broken, will never repair itself and will result in permanent paralysis. If neuron cells had not become so specialized in the spinal cord, then they would be able to repair themselves after an injury.
- Nave, R. "The Retina." of the Human Eye. N.p., n.d. Web. 7 Nov. 2013. <http://hyperphysics.phy-astr.gsu.edu/hbase/vision/retina.html>.
- "Squid Brains, Eyes, and Color." Squid Brains, Eyes, and Color. N.p., n.d. Web. 7 Nov. 2013. <http://gilly.stanford.edu/neuroscience.html>.
- "Pharynx and Larynx." Emory University. N.p., n.d. Web. 7 Nov. 2013. <http://www.emory.edu/ANATOMY/AnatomyManual/pharynx.html>.
- staff, Mayo. "Choking: First Aid." Mayo Clinic. Mayo Foundation for Medical Education and Research, 13 Oct. 2011. Web. 7 Nov. 2013. http://www.mayoclinic.com/health/first-aid-choking/FA00025.
- "Smithsonian.com." Smithsonian magazine. N.p., 19 Nov. 2010. Web. 7 Nov. 2013. <http://www.smithsonianmag.com/science-nature/The-Top-Ten-Daily-Consequences-of-Having-Evolved.html?c=y&page=2>.
- "Wisdom Teeth." American Association of Oral and Maxillofacial Surgeons (AAOMS). AAOMS, n.d. Web. 7 Nov. 2013. <http://www.aaoms.org/conditions-and-treatments/wisdom-teeth>.
- "Nervous System Guide by the National Science Teachers Association." Nervous System Guide by the National Science Teachers Association. National Science Teachers Association, n.d. Web. 7 Nov. 2013. <http://www.nsta.org/publications/interactive/nerves/health_and_disease/sc_injuries.html>.