BayCEER Workshop 2023

Predicting extinction risk by range loss: Evidence from the fossil record

Species extinction and biodiversity loss as reported by the IPCC are predicted from climate change related reduction in the geographic range (range loss). This builds on the well established IUCN Red List criterion, in which a species is considered critically endangered (>50% extinction risk) if it loses 80% of its geographic range. However, while there is clear evidence that extinction risk is related to the absolute geographic range of a species, its relationship to range loss has not been investigated. Building on fossil evidence of true extinctions (Neogene – Holocene), this study implements a Bayesian hierarchical weighted generalized additive model to investigate how extinction risk changes with the percentage decrease or increase in geographic range of a genus. Results clearly indicate how extinction risk increases with range loss. Taxon dependent differences in the relationship between extinction risk and range loss indicate a potential need for adapting its application in extinction risk predictions as well as the IUCN criteria.