Unveiling evolutionary cradles and museums of flowering plants in a neotropical biodiversity hotspot.

Abstract

Colombia, renowned as an important centre of global biodiversity, continues to harbour undiscovered evolutionary hotspots of flowering plants. The altitude-dependent hypothesis suggests that richness patterns are determined by altitude and probably influenced by climate variables. This study employs null models based on a species-level phylogeny of Colombia's flowering plants and their geographical distributions to identify evolutionary hotspots. We explore the potential correlation between elevation, climate variables such as temperature and rainfall, and the location and nature of these hotspots. The findings reveal that evolutionary cradles, which house young endemic species, are predominantly located in the mountainous regions of the Andes. Conversely, evolutionary museums, hosting older endemic species, are found in lowland regions spanning the Caribbean, Orinoco, Amazon and Pacific areas. These results demonstrate a clear elevational segregation of evolutionary hotspots, primarily influenced by temperature, thereby supporting the hypothesis under examination. Furthermore, this study identifies previously unrecognized evolutionary regions, highlighting the limited understanding of Colombia's biodiversity distribution and evolutionary history.