Beyond the value of reproductive value

Research Highlights: Lebreton, J.-D., & Oli, M. K. (2026). Reproductive value as a key concept in ecology and evolutionary biology. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.70343. Ecologists are good at counting things. Yet individuals are not interchangeable in what they contribute to a population's future. Lebreton and Oli's synthesis of reproductive value (RV) shows that this deceptively simple idea connects demographic theory, life-history evolution, spatial ecology, epidemiology and conservation. Indeed, RV provides a common currency for asking not simply how many individuals occupy a population, but where its demographic future resides. Here, I highlight this unifying perspective and argue that new technologies could take RV from a predominantly class-based quantity towards a dynamic, individualised and spatially explicit description of populations. Combining demographic models with biologging, automated monitoring, genomic information and ecological digital twins could reveal reproductive value at resolutions Fisher himself could scarcely have imagined. I further suggest that RV could enrich community-stability theory by weighting species' fluctuations by their contribution to future population persistence, thereby connecting population resilience, biodiversity insurance and ecosystem stability.