Biotic immigration events, speciation, and the accumulation of biodiversity in the fossil record

摘要

Biotic Immigration Events (BIMEs) record the large-scale dispersal of taxa from one biogeographic area to another and have significantly impacted biodiversity throughout geologic time. BIMEs associated with biodiversity increases have been linked to ecologic and evolutionary processes including niche partitioning, species packing, and higher speciation rates. Yet substantial biodiversity decline has also been documented following BIMEs due to elevated extinction and/or reduced speciation rates. In this review, we develop a conceptual model for biodiversity accumulation that links BIMEs and geographic isolation with local (alpha) diversity, regional (beta) diversity, and global (gamma) diversity metrics. Within the model, BIME intervals are characterized by colonization of existing species within new geographic regions and a lack of successful speciation events. Thus, there is no change in gamma-diversity, and a-diversity increases at the cost of beta-diversity, An interval of regional isolation follows in which lineage splitting results in successful speciation events and diversity increases across all three metrics. Alternation of these two regimes can result in substantial biodiversity accumulation.