Global determinants and conservation of evolutionary and geographic rarity in land vertebrates.

Deciphering global trends in phylogenetic endemism is crucial for understanding broad-scale evolutionary patterns and the conservation of key elements of biodiversity. However, knowledge to date on global phylogenetic endemism and its determinants has been lacking. Here, we conduct the first global analysis of phylogenetic endemism patterns of land vertebrates (>30,000 species), their environmental correlates, and threats. We found that low temperature seasonality and high topographic heterogeneity were the main global determinants of phylogenetic endemism. While phylogenetic endemism hotspots cover 22% of Earth, these regions currently have a high human footprint, low natural land cover, minimal protection, and will be greatly affected by climate change. Evolutionarily unique, narrow-range species are crucial for sustaining biodiversity in the face of environmental change. Our global study advances the current understanding of this imperilled yet previously overlooked facet of biodiversity.