Patterns of diversification on old volcanic islands as revealed by the woodlouse-hunter spider genus Dysdera (Araneae, Dysderidae) in the eastern Canary Islands

Description: Long-term erosion and subsidence cause dramatic alterations in the physical and ecological features of oceanic islands. Although oceanic islands have been extensively used as models for the study of speciation, little attention has been given to investigating evolutionary patterns in old volcanic islands that have suffered severe climatic degradation. The spider genus Dysdera has diversified across the Canary Islands and has evolved endemisms in the low-elevation, xeric eastern islands, which sharply contrast with the younger, higher, and more humid western islands. A combined phylogenetic analysis of seven mitochondrial and nuclear genes reveals that the eastern Canaries were colonized twice, although only one lineage underwent in situ diversification. Origins of the speciose lineage remain obscure, but probably preceded diversification of present-day Iberian and North African species. A second …