The human body is an extraordinary system that trumps the complexity of an atom smasher. In the face of this stupefying complexity, it is tempting to compare the inner-workings of the human body to a designed artifact. Yet the throat, in addition to other bodily organs, contains its fair share of hiccups that no sensible designer would have made. Once we recognize that our bodies are evolved organisms rather than designed machines, these deficiencies can be better understood as trade-offs rather than imperfections. In illustrating this point, the following list casts the top ten “imperfections” of the human body in an evolutionary light.
Imperfection #1: The wrist. The human wrist is great for catching footballs, swinging baseball bats, driving cars, among other daily activities. The ability to rotate our wrist is achieved by the interchangeability of the two arm bones. Alternatively, the wrist bones are thin and fracture easily. Given that human ancestors have been falling on their wrists for quite some time, why did natural selection not make those bones thicker? If the bones that constitute the wrist were any thicker, then it would lose its ability to efficiently rotate. So it is a tradeoff between two competing evolutionary advantages. Yet when scientists design a robotic arm, rather than using two thin rods, they simply use a single thick rod that can rotate 360 degrees. So the human wrist is an imperfection in design, which is exactly what one would expect if the wrist had evolved, and not what would one expect if it had been created.
Imperfection #2: The back. As people age, many begin to experience back pains. Chiropractors abound, back pain is an unfortunate corollary of human evolution that is here to stay. Humans are bipedal creatures, meaning they pedal themselves with two legs. In contrast, ancient ancestors were quadrupedal creatures, meaning they peddled themselves with four legs. So the back was originally like a bridge that supported everything. The organs dangled from the back through a connection of nerves. When the vertebrate column inclined vertically, the organs became tangled. In addition, the lower back now has to support the weight of the shoulders and has not taken kindly to this readjustment.
Imperfection #3: Sinus cavities. Another natural consequence of shifting from quadrupedal to bipedal is the displacement of the sinus cavities. In bipedal animals, the maxillary sinus cavity is located behind the cheeks on each side of the face. The placement of the drainage hole causes a great deal of grief for anyone who has ever suffered a sinus infection. The drainage hole leads to the top of the nose. As a result, the fluid fights an uphill battle against gravity. In quadrupedal creatures, however, the drainage hole is located at the front rather than the top, which allows the fluid to drain much more smoothly.
Imperfection #4: The jaw. In addition to poor sinuses, the human jaw contains more teeth than it can chew. Wisdom teeth are a superfluous set of molars located at the back of the mouth that grow-in around the age of eighteen. The wisdom teeth push into the surrounding vicinity and cause some of the neighboring teeth to grow-in sides ways. Wisdom teeth used to help our ancestors grind plant food. As the human diet changed, the human jaw bone decreased in volume. Despite serving no practical purpose, wisdom teeth continue to manifest themselves in young adult life. Wisdom teeth tend to be removed because they trap food in the back of the mouth and cause infections.
Imperfection #5: Goosebumps. Many wonder what purpose goosebumps actually serve. The answer is, they don’t have a purpose. However, goosebumps served a practical purpose for distant and extinct ancestors. In particular, animals with feathers and hair would use goosebumps for thermal regulation and to fluff up their hair to appear larger to prey. This is why goosebumps appear when people are either cold or frightened. Although humans have shred most of the ancestorial hair, the trait continues to circulate within the species. Goosebumps are, like molars, a superfluous vestige of long, forgotten ancestors that continue to manifest themselves today.
Imperfection #6: The birth canal. The shortage of the birth canal is one of the most tragic imperfections of the human body. The birth canal serves as a passageway for childbirth. The narrowness of the birth canal makes it difficult to deliver babies and can be detrimental to the life of both the mother and child. If the baby’s head is larger than the pelvic opening, then the baby cannot be born naturally. Prior to medical surgery, this complication would lead to the death of the mother, child or both. Evolutionary history reveals that the human brain rapidly swelled like a balloon within the last few million years. So much so that the birth canal has not had enough time to adapt to the expansion of the cranial cavity.
Imperfection #7: The throat. Reports indicate that approximately one person in a hundred thousand chokes to death each year. While this rate might seem small, it has been a persistent cause of death for hundreds of millions of years not only in human history, but throughout the course of vertebrate evolution. Vertebrates share the same underlying flaw—namely, the food- consuming esophagus intersects with the oxygen-consuming trachea. Although the body has a reflex that causes the trachea to close while swallowing, it is not, forgive the pun, air tight. Yet this automatic reflex is a superfluous undertaking for the human body. A safer and more efficient design would be to place the esophagus and trachea onto two separate routes. This is not an unreasonable demand. For example, dolphins eat and drink through separate holes in their bodies.
Imperfection #8: Arteries: Arteries are a double edge sword between brilliance and idiocy. On the one hand, arteries posses the remarkable ability to carry the perfect amount of blood to each region of the body. On the other hand, the material that comprises arteries is flimsy. For many people, cholesterol deposits conglomerates inside the arterial walls. This thwarts blood circulation and triggers a host of health problems that plagues modern culture, such as heart attacks and strokes. As the late George Williams once wrote, “ It is as if a Mercedes Benz designer specified a plastic soda straw for the fuel line!”
Imperfection #9: The eye. The human eye tends to be upheld as the pinnacle of creation and is a notorious example of “irreducible complexity.” It is therefore rather ironic that the eye is also an excellent illustration of stupid design. In particular, the eye’s photocells point away from the scene that is actually being looked at. As a result, light rays have to surpass a dense, concentration of cellular wiring in order to stimulate the photocells. This is like putting the wires that comprise a video camera in front of the lens. To make matters worse, the wires that connect the photocells to the brain have to figure out a way to surpass the retina. Therefore, the nerves dive through a hole on the eye’s surface which in turn, causes a blind spot.
Imperfection #10: The Recurrent Laryngeal Nerve. The recurrent laryngeal nerve is a nerve that begins at the back of the brain and ends at the larynx (the voice box in mammals). Rather than taking an expeditious route from the back of the neck to the larynx, the laryngeal nerve takes the circuitous route by diving into the chest, loops around one of the main arteries, and then stems its way back up to the voice box. The most extreme case occurs in giraffes, where the nerve makes an unnecessary twelve-foot dive down into the chest. The reason the nerve makes this unnecessary route is that it originally developed in fish that had no neck. However, with the emergence of mammals came the elongation of the neck which caused the heart to be displaced lower.
The human body is perhaps the most exquisite biological ensemble the universe has ever generated. The heart pumps blood for seventy plus years without missing a beat, while the brain possesses the ability to recollect a distant life memory in the flash of a second. It is tempting to fall upon our knees in the face of such stupefying complexity without considering how poorly designed our knees actually are. In doing so, we cherry pick the aesthetically pleasing features of the human body and ignore the imperfections that confound that revelation.
By Nathan Cranford