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Community assembly and diversification in a species‐rich radiation of island weevils (Coleoptera: Cratopini)
Author(s) -
Kitson James J. N.,
Warren Ben H.,
Thébaud Christophe,
Strasberg Dominique,
Emerson Brent C.
Publication year - 2018
Publication title -
journal of biogeography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 158
eISSN - 1365-2699
pISSN - 0305-0270
DOI - 10.1111/jbi.13393
Subject(s) - biology , genetic algorithm , species richness , ecology , phylogenetic tree , colonization , evolutionary biology , zoology , gene , genetics
Abstract Aim To test a prediction derived from island biogeographical theory that in situ speciation should make an increasingly important contribution to community assembly as islands age. This prediction is tested on estimated biogeographical histories from Mauritius (approximately 9 Myr) and Reunion (approximately 5 Myr). We additionally investigate the evolutionary dynamics of insect flight loss, as the loss of flight in island lineages can influence patterns of diversification. Location Mascarene Islands; Southwest Indian Ocean. Taxon Weevils. Methods Up to five individuals of each taxonomically described species sampled within each sampling site were sequenced for the mitochondrial gene Cytochrome Oxidase II to delimit operational taxonomic units ( OTU s). OTU s were further sequenced for the nuclear genes Arginine Kinase, Histone 3 and ribosomal 28s, to reconstruct the phylogenetic history of the group. Timings of colonization and in situ speciation events were estimated with beast 2. Results Our results support the hypothesis that present‐day species richness on the older island of Mauritius is largely the result of in situ speciation, with few colonization events, of which all but the most basal are recent. In contrast, Reunion presents a more uniform temporal spectrum of colonization times. Flight loss has evolved convergently at least five times, and speciation events associated with flight loss are significantly younger than speciation events that have not resulted in flight loss. Main conclusions Patterns of community assembly on the islands of Mauritius and Reunion fit a model where the addition of new species and species turnover is increasingly dominated by in situ speciation as an island community matures. Repeated flight loss indicates selection for flightlessness, with the young age of flightless lineages suggesting higher extinction rates over longer evolutionary time‐scales and little influence on present‐day species richness.