Tom Leinster abstract Tom Leinster, School of Maths, UoE Measuring diversity: the importance of species similarity In ecology, genetics, and several other disciplines, the need has arisen to have a numerical measure of diversity. The trouble is that no one can agree on what the word "diversity" means. I will present some joint work with Christina Cobbold, showing that many of the existing measures of diversity can be unified into a single, highly flexible and versatile, system of measures. An important feature is that it allows inter-species similarity to be factored in (unlike the most popular measures in ecology, for instance, which implicitly assume that different species have nothing in common). Assuming no background knowledge, I will explain this work, including both the mathematical aspects and its application to real populations. This article was published on 2025-04-22