100 years of discovery reshaped global biodiversity maps, study finds

Over the past century, scientific discoveries have significantly reshaped our understanding of global biodiversity, particularly altering perceptions of where the world's most diverse terrestrial vertebrate species are concentrated. A new study published in Ecology Letters examined how a century of taxonomic discoveries, from 1920 to 2020, influenced estimates of biodiversity hotspots.

The research found that while diversity patterns for birds remained relatively stable, and environmental drivers for birds and mammals were consistent, reptiles and amphibians underwent substantial reconfiguration. The study revealed that 20.3% of reptile diversity centers and 31.7% of amphibian diversity centers shifted to different regions over the 100-year period. This shift highlights how incomplete taxonomic knowledge can lead to an incomplete picture of biodiversity distribution.

Regions like Australia and Southeast Asia have emerged as more prominent biodiversity centers, especially for reptiles and amphibians, as new species within these groups were discovered and formally recognized. The study's methodology focused on range-weighted rarity, identifying areas with species that have particularly restricted distributions, rather than just areas with the highest number of species.

These findings suggest that ongoing species discovery can directly influence conservation priorities by changing which parts of the world are recognized as most critical for biodiversity. The study also noted shifts in the environmental factors associated with species richness, with precipitation emerging as a more crucial element.