Evolutionary Biology Through the Lens of Medicine

When thinking of the word evolutionary I often think of species developing or changing yet I rarely think of practical ideas like medicine or healthcare progressing. Although having species evolve is important in its own unique ways, having medicine evolve is something that I think tends to get over looked and not even thought of. Medicine evolving is an area where it almost needs to happen to keep up with the day to day or generation to generation changes . This is just one of many reasons to why evolutionary biology is an important field of study. Evolutionary medicine uses prior theories of evolution to help understand our health, illnesses, and diseases to which improves our quality of life.

The word evolutionary is derived from the word of evolution meaning “the process by which new species or populations of living things develop from preexisting forms through successive generations”. From this comes the study of evolutionary biology that studies life on earth. Life has survived through evolution and adaptation but that is not all. Evolution is more than looking at the species physically, but also on the molecular level such as looking at genes, cells, and diseases. Specifically, evolutionary medicine uses the principles of evolutionary biology to look a little deeper into areas where it is needed the most. As stated by Karla Moeller, evolutionary medicine “uses what we know about evolution to improve understanding of our health, why we get sick, and how we can better prevent and treat disease”. With no knowledge and or research in evolutionary biology it would not allow for a new field such as this one to arise and help with the understanding of our health.

Evolutionary Biology and Evolutionary Medicine

Both branches go hand in hand meaning that they both advance each other. Questions are asked forming new thoughts and ideas allowing for this biological field of study to keep growing and giving a reason to why more people should focus and study this field. Evolutionary medicine is not a practice but a scientific field of study to which poses new questions to get answered and applies principles from basic science to solve issues in public health. Although evolution is based on natural selection, people have come to find the opposite of that. For example, diseases are a major topic in medicine. These diseases are not shaped by selection because they are not what people select for as they are harmful to humans and the community. But adaptations that have come from this are the symptoms which have evolutionary reasons to why they have arisen. Then through studying evolutionary biology, these reasons can be accounted for and applied to knowing why these painful adaptations happen and are still here today

With evolutionary medicine on the rise as a major area of discussion, many people are now realizing how important it truly is. Many doctors and physicians agree that being ignorant to the thought of evolution needs to cease. So much so that questions are now being placed on medical exams encouraging students to take evolution in their undergraduate years. It has been recommended by the Association of American Medical Colleges that evolutionary thinking is critical and important for medical education. Within the last few years the MCAT, medical college admissions test, has entered questions involving evolution getting students to think critically on another level.

With more and more students filling these classrooms more of these classes will need to be offered creating an influx of recognition as evolutionary biology being a major science of study. When trying to gain acceptance into medical school through the undergraduate years courses such as physics, calculus, and chemistry are required to be met at a specific level yet are rarely used while practicing in a clinical setting. It is stated that a lot of medical schools discuss developmental biology as an important topic of understanding yet evolutionary processes from the past and contemporary times are just as equally valuable. Through a class of evolutionary medicine the perspective of how evolution can affect human health would be enriched. Core principles would be taught to expand and empower the medical field. So with evolution being a part of graduate student work and in the professional field of medicine, it is important to have obtained knowledge from the evolutionary biology science in the undergraduate years.

Because this is now just becoming on the rise and doctors are not completely aware of this field, there tends to be medical misconceptions that have formed in the past and continue today. Although there is still some confusion, it has been shown in today’s world, along with some examples that will be described in this paper, that knowledge in evolution can be beneficial and have been shown to save lives, avoid suffering, and prevent certain issues. Many have come to this realization that what has been done so far including evolutionary research has had great payoffs, such as people living longer and in better conditions . Not only does evolutionary biology and knowledge help treatment but it also gives reasons to why certain diseases or disabilities still exist today.

Through a panel that was held, questions were asked and answers were provided by multiple biologists on what they believe to be core principles of evolutionary medicine. When the results came through,100% of the biologists believe that life history theory is a major topic of discussion because it allows for the understanding of the origin of life and how over time stages of life and health have evolved. Another major topic that was 100% agreed upon was cultural practices. Part of selection is based on culture and a part of culture is medicine. Since there are different cultural practices around the world, looking at them from an evolutionary perspective can give credence as to why certain practices, diets, or behaviors persist leading to why specific diseases or pathogens exist in certain areas today. Lastly, 100% agreed upon by the biologists , was the topic of evolutionary processes. Ideas like natural selection, mutation, or genetic drift will help with the understanding of where traits and diseases have formed and how they have affected our daily lives. Some key terms that are discussed when talking about evolution are known to be a possible explanation to some disorders and diagnoses. For example antagonistic pleiotropy can explain gout or Alzheimer’s disease while adaptation to environment can describe obesity, hypertension, or type II diabetes . So, while many people are aware of these disorders it is helpful to realize what can be causing them or leading them to happen. Basic knowledge from an evolution class will help explain what these terms mean in order to draw conclusions. This discussion was held to create principles of evolutionary medicine to provide a curriculum of development in the evolutionary medicine field.

What is Evolutionary Medicine?

As evolutionary medicine deals with diseases, conditions, and human health it is important to know where it all started. In the past people grew up living an unhealthy and unsanitary life, almost living with the bacteria as they did not have a shelter or home like most people do today causing them to live on edge and be worrisome . Knowing and looking at this under an evolutionary perspective allows for answers and reasons to be drawn. For example when they were to hear a noise of an animal coming near, anxiety and awareness helped them, giving them the response to get up and run or else they would be eaten. At this point in time this trait was beneficial, but now that time has passed and changes have been made, anxiety is now looked at as a downfall. Knowing where this emotion has come from gives reasons to why it is here today. Also because of this unhealthy lifestyle , immune systems of people grew and formed around these situations to fight against high numbers of bacteria and parasites. But now that times and situations have changed, our immune systems have not fully adapted leaving us with a stronger immune system than what some of us need. This then creates the immune system to act against itself called autoimmunity. This is shown to be linked to type 1 diabetes, arthritis, or cardiovascular disease. Although there are other reasons for why these diseases may be occurring, this is one conclusion they can be drawn based on evolutionary reasons .

Through the bodies different systems such as nervous, hormonal, or immune it can be seen through evolutionary history of how the body has come to maintain homeostasis. For example when an infection arises the different body systems need to work together to defend from this danger making sure to keep the body stable of its elements. Through basic evolutionary biology it is known that humans share and may have evolved these systems from other species, such as having common hormones with vertebrate animals, a comparable immune system to rodents, and have a similarly organized nervous system with sharks and rays. Because of this, medical practices can possibly be tested on these species before antibiotics or medical procedures are used on humans. But in order to know what humans share with other species, evolutionary biology must be studied and applied allowing for humans to gain another advantage in the medical field.

A study was done over seven years that used evolutionary insight to create a therapy for an incurable disease. When the world started to become more sanitary and clean bacteria and worms became removed from hygiene. This then changed the way human immune systems reacted. Because worms had evolved the ability to stop immune responses and the co-evolved parasite was removed, the human immune system began to respond. Thus removing these worms allowed for parasites to influx creating more infections in people. This study then took patients with multiple sclerosis, some having worms and others not, with the results showing those who did not have the worms to worsen faster over time. Because of this doctors have come to create a recently discovered therapy to this once untreatable disease using worms. Through this study it proves to show that studying evolution really does have its benefits in the medical field. Without this realization of worms evolving there possibly could still be no cure to multiple sclerosis.

With the world continuing to grow and more and more people are being born, humans have encountered thousands of variations of genes that have been passed on from their ancestors. Some people may have a variation to resist or metabolize certain drugs or antibiotics leading to possible life threatening issues or even death. These genetic variations are important for doctors to look at when preparing treatments or therapies leading to personalized medicine showing how genetic variation plays an important role for medical science. As stated by Naugler, “evolutionary medicine has also proven key to explaining the reasons for the development of antibiotic resistance and has the potential to explain cancer pathogenesis”. Persuaded by evolutionary biology, cancer has been labeled as “microcosms of evolution”, meaning that these cancer cells act similarly to other cells competing against each other. Knowing this, correct treatment can be used to help fight these cells. If correct antibiotics are not used over time and have been used repeatedly then the body can evolve into forming a resistance to them becoming ineffective. So overall evolutionary medicine does help with medical treatment but we are not to the point to find continuous answers requiring more people to study evolutionary biology. When looking at pasts and how things have or have not evolved or adapted allows for doctors to prescribe different antibiotics that may be more effective or beneficial in the long run. Because of this, this field of study can become very important in teaching today’s doctors and potential doctors that are involved in any type of medicine.

Taking the evolutionary knowledge into medical practice does not change the way physicians treat or act to their patients on a day to day basis. The way physicians treat patients depends not on theories but studies that have been done on humans or similar related species that are seen as reliable. But this does not mean that evolutionary knowledge is not needed. Evolutionary biology is a guide for research to better understand the human body, what it entails, and what the body is effected by. It also offers help into why diseases still exist today, what environments they thrive on, and how to treat these diseases people must deal with. To do so methods and techniques from evolutionary biology are used in a way that becomes helpful to medicine.

A method that is common within evolution that is useful in the medical field is through the use of phylogenetic trees. When tracing diseases through the use of phylogenetic trees, biologists are able to see the spread of pathogens and diseases to when there will likely be a future epidemic. Knowing this allows for biologists and doctors to be more aware of their situations and what is predicted to occur so they can prepare and prevent a pandemic through the use of treatments and vaccines. Lastly, through a study that was done using phylogenetic trees biologists came to a conclusion that what was once a hypothesis for HIV was wrong. They distinguished that HIV was not introduced into Africa from the polio vaccine but from something different. This then gave confirmation to doctors that this treatment could still be a reliable source. Using the evolutionary method of phylogenetic trees in conjunction with medicine allows for doctors to be better prepared in judging new findings they come upon.

Conclusion

Evolutionary biology, as seen throughout this paper, becomes very important when looking at it through the lens of medicine. Having knowledge about evolution may lead to answers that can change someone’s life by preventing a disease, creating a treatment, or give reasons to why such a thing may occur. With more people studying evolutionary biology and becoming knowledgeable about its intricacies, it will hopefully provide benefits in educating the general public and physicians about our human health and where it all started. Learning about evolutionary biology in the undergraduate years may enhance knowledge to understand the past and to possibly predict the future.