Beyond Species Richness: The Importance of Phylogenetic Dimensions of Biodiversity in Disease Ecology.

Biodiversity loss and anthropogenic changes to community composition have profound effects on disease emergence and transmission. These alterations influence disease risk by either amplifying or reducing pathogen spread, depending on the spatial scale, ecological context, and the indices used to characterize biodiversity. We argue that species richness alone is often insufficient and that evolutionary relationships among hosts offer critical and underappreciated insights into disease dynamics. By drawing on recent empirical and theoretical studies, we highlight how phylogenetic approaches can enhance our understanding of the dynamics between biodiversity and disease. Future studies must move beyond descriptive use of phylogenetic diversity and develop mechanistic frameworks that integrate community structure and host evolutionary relationships into transmission processes to better assess disease risk under global change.