Of all the species in the world, the evolution of human beings is the most controversial. People, especially religious ones cannot stand the idea that humans don’t have a divine origin and existence and that we are related to the other animals. For fans of creationism or intelligent design, it is hard to accept that humans underwent the process of evolution to reach the current state. They often site the human body especially the eye as a perfect example of design as our body is too complicated to have evolved naturally according to them. Well, I am okay with it provided when a trained person looks at this so called “design”, he should not be puzzled as to why certain parts are in a particular way because when we look carefully at the human body, that is precisely what we feel.
Therefore I would like to call on the scientific and engineering outlook of the reader in this article because I am going to site a few examples where it is required for you to think as to whether we are actually designed or not. Let me first talk about design as we understand from our lives. Any good designer would design a machine or a drawing with the minimal amount of defects. Further he or she would make sure that the design is simple and optimized enough so that troubleshooting is easy later on. Furthermore, he or she would make sure that there is a logic behind putting a component in a particular place. Therefore a good designer can easily make out whether a machine’s design is defective or illogical in some way by looking at it.
I request you to look at the following few examples to have an insight into what I mean:
- The Recurrent Laryngeal Nerve – It is a nerve that supplies motor function to the larynx and travels from the brain to the larynx. However, it does not take a direct route. Instead it goes all the way to the heart, wraps around a major artery and then goes up to the larynx. It is puzzling as to why the nerve takes such a detour for no reason. In fact, in giraffes, the nerve travels 15 feet to the heart and then goes up to the larynx which doesn’t make sense. If we were designed, then the designer would simply put the nerve in a direct route from the brain to the larynx. It’s as simple as that. What really happened is that the fish like ancestors of modern tetrapods had the nerve direct as the heart was above the gills, as it is in modern fishes. But over the course of evolution, as the neck extended, the heart became lower in the body and unfortunately the laryngeal nerve got caught on the wrong side of the heart. A designer’s eye would easily dismiss this as a bad design. In the following video, Oxford biologist Richard Dawkins will demonstrate the detour of the recurrent laryngeal nerve in a giraffe.
- The Human Eye – This is cited as the most perfect example of intelligent design. But from an engineering perspective, it is not perfect at all. A person who make a camera will make sure that all the wiring is at the back of the film and not in front of it. Similarly if a eye is designed, then obviously all the nerves should be behind the retina. Unfortunately in human eyes, the nerves are in front of the retina. And where the optic nerve leaves the eye, there is a hole that creates a blind spot, which is the reason why our eyes jiggle. We don’t have a functional reason for our eyes to be this way except that historically the common ancestor of all vertebrates did not have a better retina available to work with. Now, those of you who want to bring in God’s “divine purpose” behind this should know that an octopus’s eye doesn’t have this problem. All the wiring is behind the retina for the octopus. In fact, the octopus eye is a much better “design” compared to humans. This link will tell you exactly what I mean by blind spot. The famous German psychologist Hermann von Helmholtz once said that if an engineer had given him the human eye, he would send it back. The video here would show you how the eye can actually evolve naturally without any divine intervention.
- Vestigial Structures – An engineer or designer would want his design clean. He wouldn’t want an unwanted component in the machine without serving a purpose. As in the human body and in other species, there are plenty of structures that do not serve any particular purpose. Right from the DNA to visible organs, one wonders why a designer would put them there. The answer as to why these vestigial structures such as the pelvis in snakes, human appendix, the male nipples, the tail bone etc. exist comes from evolution. These are relics from a common ancestry where these structures once had a function. As humans evolved, some of these functions either stopped or changed thereby creating these vestiges. Not only in the organs but also in the DNA we find vestiges. There are several genes that form part of what is called genetic junk. The only reason they are there is because evolution didn’t clean it up properly.
- Fatal Errors – There are some really fatal mistakes in the human body. Only because of modern medical care that we can counter death caused by these flaws. For instance, in women, the fertilized egg can mistakenly implant into the fallopian tube, cervix or ovary instead of the uterus causing ectopic pregnancy because of a cavity between the ovary and the fallopian tube. Before modern surgery, this used to kill both the woman and her baby. In men, the testes develop first in the abdomen and then migrate to the scrotum. This creates weak points in the abdominal wall where hernias can form in future and without modern surgery, it is a sure way to die. The human pharynx is yet another design flaw. It is the passage used for both ingestion and respiration, which increases the risk of choking. And as mentioned above the appendix is a vestigial organ that serves no known purpose. However, if you get appendicitis, it is a sure shot way to die.
These are just a few examples of imperfections in the seemingly perfect human body. There are hundreds of such examples and in some cases the design flaw is so much that it can be fatal as described above. A designer with any level of logic or common sense would never create a body like this. Therefore the only conclusion that can be made is that either there is no designer or the designer is a very bad designer. Everything from top to the bottom in our body is trade-offs that came about through millions of years of evolution. It’s an undeniable fact.