Legacy of archipelago history in modern island biodiversity - An agent-based simulation model

Aim Geological processes of island growth and erosion, in addition to eustatic sea-level fluctuations, alter key physical properties of oceanic islands, such as area, elevation and isolation over time. These dynamics operate over similar time-scales to the biogeographical processes of colonization, speciation and extinction, and thus should strongly affect island biodiversity patterns as we observe them today. Here, we study the effects of geological history and eustatic sea-level fluctuations on biodiversity patterns in the Hawaiian, Galapagos and Canary Islands, using an agent-based simulation model. Location Hawaiian Islands, Galapagos Islands and Canary Islands. Time period Geological history up to 20 Ma. Taxa Spermatophyta, Pteridophyta, Passeriformes, Lepidoptera and Coleoptera. Methods We analysed the effect of geological, eustatic and biogeographical processes via a spatially explicit agent-based simulation model. We compared the emergent patterns with observed species richness and the proportion of single-island endemics across the considered taxa and archipelagos. Results Our results suggested that both geological and eustatic processes have affected biodiversity assembly in the Hawaiian and Galapagos Islands. In the Canary Islands, we found only the proportion of single-island endemics to be affected by historical configurations. Main conclusions Our results highlight the key role of past geological and eustatic processes in affecting modern insular biodiversity patterns.

Automated summary

The study examined the impact of geological processes and eustatic sea-level fluctuations on biodiversity patterns in the Hawaiian, Galapagos, and Canary Islands. Findings suggested that both geological and eustatic processes have influenced biodiversity assembly in the Hawaiian and Galapagos Islands, while historical configurations only affected the proportion of single-island endemics in the Canary Islands. Overall, the results highlight the importance of past geological and eustatic processes in shaping modern insular biodiversity patterns.