The original definition of biodiversity is the number of species in a community. It has been extended in many ways, often using ad-hoc indices.
This course introduces a unified approach to measuring biodiversity, based on information theory, which allows biodiversity to be described as an effective number of categories (usually species) corresponding to the question at hand: taxonomic diversity when all species are considered equivalent, phylogenetic diversity when their evolutionary proximity is taken into account, and functional diversity when the distance between pairs of species does not fit into a tree.
