Selectivity of terrestrial gastropod extinctions on an oceanic archipelago and insights into the anthropogenic extinction process

Anthropogenic impacts have led to nonrandom losses of phenotypic diversity among terrestrial gastropods in the Ogasawara Islands, with extinction patterns varying by island and type of threat. Extinct species exhibited significantly smaller geographic ranges compared to surviving ones, but current declines do not show significant range differences between threatened and non-threatened species. Extinctions were selective based on shell spire index (SI), a functionally important trait, though the relationship between body size and extinction vulnerability differed among extinction agents—some being strongly size-selective while others were not. The study suggests that as anthropogenic threats have shifted from habitat loss to predation over time, so too have the patterns of biodiversity loss, indicating that resilience to one type of threat does not ensure long-term survival.

Chiba, S., & Roy, K. (2011). Selectivity of terrestrial gastropod extinctions on an oceanic archipelago and insights into the anthropogenic extinction process. Proceedings of the National Academy of Sciences, 108(23), 9496–9501. https://doi.org/10.1073/pnas.1100085108