How Do Local Medical Systems Work? An Overview of the Evidence

Local medical systems (LMSs) are shaped by the interaction of human beings with biota, so understanding how human beings use natural resources for their survival is one of the most discussed topics in ethnobiology studies. Although many studies have focused on describing the structure of LMSs (for example, plants or animals used for medicine), there is a need to better understand their functionality (for example, how the species are used) and maintenance, with emphasis on their resilience. This synthesis is based on a literature review about the functioning of LMSs. Also, to better understand the dynamics of these medical systems, it takes into account literature about learning processes and knowledge variation across different spatial scales. The evidence indicates that the incorporation and differential use of medicinal resources can be predicted by the social-ecological theory of maximization, which postulates that human cognitive and behavioral mechanisms mediate the selection of strategies that maximize benefits and reduce costs in human interactions with the environment, thereby reinforcing the complexity and dynamism of LMSs since several factors can affect their functionality. We identify gaps in this area and suggest directions for future research that seeks to understand the functionality of LMSs.