Exploring Metrics of Biological Diversity to Better Predict and Respond to Emerging Diseases

The emergence of infectious diseases is largely driven by spillover events from animal communities into human populations, with zoonotic pathogens accounting for 75% of novel infectious agents. In recent years, the incidence and prevalence of these pathogens have been on the rise, and efforts to understand the underlying ecological principles responsible for the reported increases have highlighted the role of biodiversity loss as a major contributing factor. Despite its role in pathogen emergence, how biodiversity is measured can differ drastically and may underlie variability in study results, making the impacts of biodiversity on pathogen behavior difficult to untangle. Here, we first examine how landscape parameters affect disease transmission and then evaluate metrics used in various disease systems to discuss the ways that different aspects of biodiversity, such as functional, phylogenetic, and trophic diversity, can provide novel insight into the relationship between host communities and disease emergence and transmission. We focus on the tick-borne pathogen that causes Lyme disease in this review and discuss how functional, trophic, and phylogenetic diversity can improve our understanding of the relationship between host community structure and disease transmission. The growing public health burden of tick-borne diseases necessitates holistic thinking to inform actions to decrease the risk of disease to humans and protect natural communities.