Darwinian Medicine and the Evolution of Diseases: An Introduction
Sneezing, fever, coughing, nausea, diarrhea, vomiting, and inflammation; these symptoms, often believed to be the manifestations of disease, are in actuality defensive adaptations, posited by Darwinian Medicine to be the direct result of an organism’s evolutionary legacy. Humans feel pain because in the past, such a response towards a harmful stimulus permitted survival. Women within their early months of pregnancy experience morning sickness, not due to some defect, but in order to defend the fetus against any harmful contaminants that may jeopardize development. The same principles that govern Darwin’s adaptive and evolutionary principles persist here as well, thereby allowing an entire sub-field within science to exist, in which cures for the future are perhaps contained within the human past.
The modification of the human genome to various pathogens has not led, as one might suppose, to the elimination of disease. This paradox is due to a process known as coevolution, in which one organism, for this instance the pathogen, changes in direct correspondence to the modifications of its host with which it interacts. HIV provides an excellent illustration of this concept: the virus adapts very rapidly to the vast array of anti-viral drugs, leaving many strains to be drug-resistant and thereby untreatable.
The evolutionary legacy of humans has also instigated a number of afflictions, born solely as the result of adaptations. For example, bipedalism, or the ability of upright locomotion, provided countless advantages for early hominids, such as a greater carrier capacity and the ability to use limbs for purposes of manipulation. Yet, the upright posture required of such feats consequently produced a number of difficulties, including lower back pain, a more vulnerable location of a fetus, and the internal shifting of organs.
But above all else, civilization is perhaps the most costly of human adaptations. Arthritis and carpal-tunnel have become a commonality due to the preeminence of technology. Cancer, rickets, obesity, and heart disease can be linked to society’s dependence upon agriculture. The ability of populations to survive in colder climates created Vitamin D deficiencies, such as weaker bone structure and abnormal growth patterns. Excess dietary fats contained within calorie enhanced, high-energy food have paved the way for heart attacks, stroke, and diabetes.
While successive adaptations have allowed modern humans to escape the same fates of their distant ancestors, who suffered from brief life spans, heightened childhood mortality rates, and high-risk occupations such as hunting, the contemporary world, created via rapid cultural evolution, has affected the human populace in a strikingly different, and just as dangerous manner. There is, although, a stark contrast between past and present afflictions, seeing that most diseases plaguing current populations are consequences of human actions.
Copyright Lilith Eden 2011. All RIghts Reserved.
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