In his book, Joralemon uses the “Ecological/Evolutionary” model to study the outbreak of cholera in a population. While the model as a whole tries to explore the relationship between humans and their environment, and how sickness interacts between the two, the model is also laden with evolutionary theory. That is, the perspective uses the analytical lens of popular evolutionary concepts such as natural selection to examine the evolution in the relationship between bacteria (cholera) and its host (humans). As a result, the model suggests relationships between what one sees in society and the level of environmental adaptation in that society.
The usefulness of any model is generally based on two factors: 1) the ability to predict; 2) the ability to give a unique perspective on phenomenon. For the first principle, while the ecological/ evolutionary model may be more applicable in some societal contexts, it may be less applicable in others. Thus, we encounter the example of a society with a high fertility rate but not necessarily a hygienic environment. In this example, there might be a number of different factors working in that society in addition to putative evolutionary ones. This “dissonance” between the model and its prediction should be mediated by the unique perspective that the model offers.
Indeed, while the model (particularly a model applied in a complex societal setting) may not always be correct, it does shed light on certain factors that are useful. For example, in societies where the link between health conditions and environmental adaptation is not seemingly robust, that may lead one to understand the absence or attenuation of certain factors that are present in other societies. Overall, the model is not expected to be highly predictive in every setting; rather, it should be treated as a (fallible) analytical lens, that along with other models, helps to engender a greater understanding of the relationship between setting, people, and disease.