Authors: Pipins, Sebastian; Pollock, Laura;Baillie, Jonathan;Owen, Nisha;Gumbs, Rikki;

The biodiversity crisis is set to prune the Tree of Life in a way that threatens billions of years of evolutionary history. To secure this heritage along with the benefits it provides to humanity, there is a need to understand where the greatest losses are predicted to occur. We therefore present the first study mapping threatened evolutionary history for all tetrapod groups, globally and within Biodiversity Hotspots, as well as revealing patterns of Evolutionarily Distinct and Globally Endangered (EDGE) tetrapod species. We found that threatened evolutionary history peaks in the Guinean Forests of West Africa, whilst EDGE richness shows high endemism and peaks in Madagascar. We then revisited the EDGE Zone concept for spatially prioritising phylogenetic diversity, using a novel complementarity procedure with uncertainty incorporated for 33,628 tetrapod species. This resulted in 25 priority areas, which are insufficiently protected and disproportionately exposed to high levels of human pressure. Together, they occupy less than 1% of the world’s surface but harbour one-third of threatened evolutionary history, half of which is found nowhere else. We believe these EDGE Zones can highlight areas of immediate concern to the researchers, practitioners, policy makers, and communicators looking to safeguard the Tree of Life.