Introduction: Natural Selection
Natural selection has helped humans identify the most crucial areas that impact genetic adjustment to the environment (Vasseur and Quintana-Murci 596). With the assistance of evolution, it is possible to forecast the engagement of different genes in human illnesses. Much progress has been made in genetic investigations that led to a better understanding of selection’s consequences on the diversity of the human genome (Vasseur and Quintana-Murci 596).
However, despite a variety of research studies and achievements done in the field of natural selection, there are still some disease incidences that may be regarded as “a by-product of past adaptation to other selective forces and changes in lifestyle” (Vasseur and Quintana-Murci 596). According to Lohmueller, the genetic load across populations has not altered over the decades, and the efficacy of natural selection has not changed across populations (139). Therefore, scholars admit that the current state of development of natural selection is not sufficient to explain some serious diseases.
Background and Problem Framing
Some specialists consider the problem of natural selection’s failure to eliminate diseases as an outcome of industrialization. In particular, it is believed that such health issues as allergies, drug resistance, or lactose intolerance develop due to environmental causes as well as genetic reasons. One of the reasons for this consideration is that natural selection has stopped influencing the human populations in industrialized societies. As a result, people with deleterious genes can survive, reproduce, and pass the genes to subsequent generations. The key argument of the current paper is that this interpretation is true. Concepts from scholarly literature are used to prove that natural selection has not eliminated the spread of diseases to a sufficient extent.
According to Colautti and Lau, there is currently no clear differentiation between genotypes belonging to the native and introduced range (1999). Scholars note that selection differentials are more stable in introduced species than they are in native ones. At the same time, selection gradients are stronger in native species. Thus, there is a possibility of selection to promote adaptation, although there is not enough evidence of this phenomenon (Colautti and Lau 1999). Therefore, it is recommended to employ classic evolutionary approaches to establish the frequency of adaptive evolution and its impact on the formulation, spread, and effect of invasive species.
Lactose Intolerance
One of the serious health issues that have not been managed by natural selection is lactose intolerance. This condition is a considerable disadvantage for many people who cannot consume dairy products. There are three issues capable of letting humans manage disadvantages inflicted by lactose intolerance. The first one is represented with mutations that developed in certain populations, such as African nomads and the North European Celtic societies (Silanikove et al. 7312).
The second factor is concerned with the ability to create low-lactose products such as yogurt and cheese. The third issue is associated with colon microbiome adaptation that enables lactose intolerant people to subjugate the intolerance (Silanikove et al. 7312). The problem of lactose intolerance is rather severe since lactose is the most valuable source of energy during the first months of life (Di Rienzo et al. 18). While the majority of humans is born with the ability to digest this nutrient, there are also those whose life is complicated due to intolerance and the need for finding other ways of providing energy. Since there is no single effective approach to treating lactose intolerance, it is possible to conclude that evolution has not been successful in eliminating this problem.
Resistance to Drugs
Another dimension of evolutionary biology’s role in public health concerns drug resistance. According to Perron et al., the progress of drug resistance has been a crucial component of the development of evolutionary theory, particularly the theory associated with the genetic foundation of new adaptation elements (211). Perron et al. argue that the productive and stable management of resistance demands a thorough understanding of this concept (211).
The evolution of microbial pathogens is considered a serious public health crisis. According to the European Center for Disease Prevention and Control, nearly 25,000 individuals die in Europe annually due to drug-resistant bacterial infections (qt. in Perron et al. 211). What concerns the human viewpoint, resistance to drugs is the mechanism by which pathogens create defenses against the pharmacological constituents employed in infection treatment (Perron et al. 212). Still, scholars remark that antibiotics belong to a more complex molecule category called secondary metabolites (Perron et al. 212). Moreover, the majority of antibiotics are multifunctional, including toxins, pigments, and different effectors.
The insufficient efficacy of natural selection in the process of protecting people from deadly pathogens is analyzed in a study by Al-Saeedi and Al-Hajj. Scholars remark that although the invention of antibiotics has promoted the overall healthcare situation, there is no method that could help avoid the appearance of resistance to drugs (Al-Saeedi and Al-Hajj 333). Taking Mycobacterium tuberculosis as an example, Al-Saeedi and Al-Hajj demonstrate that there can be a variety of mechanisms that promote drug resistance (333). Scholars also note that genetic background plays a crucial role in drug resistance. Thus, this is yet another example of how individuals carrying deleterious genes pass their genes to subsequent generations despite evolutionary processes.
Food Allergies
The third critical issue concerned with the topic of natural selection is presented with allergies. One of the most common types of allergies that has a detrimental impact on people’s lives is food allergy (Bacal et al. e151). The quality of life of people suffering from this condition is seriously damaged. Allergies may lead to suffocation or even death. Savage and Johns remark that the prevalence of food allergies is between 5 and 10 percent at the global rate, and there are no clear reasons for their spread (45). Two of the most common explanations of food allergies are “the acquisition of clinical allergy” and the persistence of this condition (Savage and Johns 45).
Taking into consideration the seriousness of the consequences of this health issue, it is crucial to come up with effective methods of dealing with it. However, despite a variety of evolutionary changes, no radical measures preventing individuals from the risk of allergies have been found. Thus, it is possible to conclude that evolution has not produced effective ways of managing this critical health issue.
Conclusion
In the process of evolution and natural selection, many alterations in humans’ organisms and their abilities to accommodate have been made. However, some scholars argue that the efforts taken are not enough to provide people with the highest quality of life. It seems reasonable to agree with these researchers since there are many crucial issues, such as food allergies, lactose intolerance, drug resistance, and others which decrease the quality of life of some individuals. Taking into consideration the findings of the analyzed scholarly papers, it seems reasonable to state that evolution has not succeeded in maximizing people’s opportunities for a healthy lifestyle. Such an occurrence is associated with industrialization that led to the inability of natural selection to impact some human populations due to their living conditions.
Works Cited
Al-Saeedi, Mashael, and Sahal Al-Hajoj. “Diversity and Evolution of Drug Resistance Mechanisms in Mycobacterium Tuberculosis.” Infection and Drug Resistance, vol. 10, 2017, pp. 333-342.
Bacal, Liane R., et al. “The Impact of Food Allergies on Quality of Life.” Pediatric Annals, vol. 42, no. 7, 2013, pp. e151-e155.
Colautti, Robert I., and Jennifer A. Lau. “Contemporary Evolution During Invasion: Evidence for Differentiation, Natural Selection, and Local Adaptation.” Molecular Ecology, vol. 24, 2015, pp. 1999-2017.
Di Rienzo, Teresa Antonella, et al. “Lactose Intolerance: From Diagnosis to Correct Management.” European Review for Medical and Pharmacological Sciences, vol. 17, no. 2, 2013, pp. 18-25.
Lohmueller, Kirk E. “The Distribution of Deleterious Genetic Variation in Human Populations.” Current Opinion in Genetics and Development, vol. 29, 2014, pp. 139-146.
Perron, Gabriel G., et al. “Fighting Microbial Drug Resistance: A Primer on the Role of Evolutionary Biology in Public Health.” Evolutionary Applications, vol. 8, no. 3, 2015, pp. 211-222.
Savage, Jessica, and Christina B. Johns. “Food Allergy: Epidemiology and Natural History.” Immunology and Allergy Clinics of North America, vol. 35, no. 1, 2014, pp. 45-59.
Silanikove, Nissim, et al. “The Interrelationships Between Lactose Intolerance and the Modern Dairy Industry: Global Perspectives in Evolutional and Historical Backgrounds.” Nutrients, vol. 7, 2015, pp. 7312-7331.
Vasseur, Estelle, and Lluis Quintana-Murci. “The Impact of Natural Selection on Health and Disease: Uses of the Population Genetics Approach in Humans.” Evolutionary Applications, vol. 6, no. 4, 2013, pp. 596-607.