Browsing by Author "Wayne, Robert K."
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- Multidisciplinary approach to evaluate adequacy of protected areas in the Azores to preserve current levels of biodiversityPublication . Amorim, Isabel R.; Borges, Paulo A. V.; Pereira, Fernando E. A. P.; Wayne, Robert K.Many of the endemic species that are found on islands have very restricted distributions and naturally small population sizes, being therefore highly susceptible to extinction. Arthropods are among the animal groups most severely affected by extinction on islands, and although they represent more than half of the Azorean terrestrial endemic species, they were not used to assess conservation priorities in the Azores. In this study we used a multidisciplinary approach, including field surveys, traditional taxonomy, molecular assays, and the speciose beetle genera Tarphius and Trechus, to evaluate the adequacy of protected areas in the Azores in biodiversity preservation. The data indicate that the area protected in the Azores is insufficient to guarantee the maintenance of species richness and genetic diversity of endemic Tarphius and Trechus beetles. Because all Tarphius and Trechus populations had exclusive haplotypes, and genetic variability within species is geographically structure, we argue that they should be treated as distinct conservation units and that the maximum number of populations should be protected in order to preserve current levels of biodiversity, and thus arrest the generalized trend of insular biodiversity decline.
- Phylogeography and molecular phylogeny of Macaronesian island Tarphius (Coleoptera: Zopheridae): why so few species in the Azores?Publication . Amorim, Isabel R.; Emerson, Brent C.; Borges, Paulo A. V.; Wayne, Robert K.AIM: We used a phylogenetic framework to examine island colonization and predictions pertaining to differentiation within Macaronesian Tarphius (Insecta, Coleoptera, Zopheridae), and explain the paucity of endemics in the Azores compared with other Macaronesian archipelagos. Specifically, we test whether low diversity in the Azores could be due to recent colonization (phylogenetic lineage youth), cryptic speciation (distinct phylogenetic entities within species) or the young geological age of the archipelago. LOCATION: Macaronesian archipelagos (Azores, Madeira and the Canary Islands), northern Portugal and Morocco. METHODS: Phylogenetic analyses of mitochondrial and nuclear genes of Tarphius beetles of the Azores, other Macaronesian islands and neighbouring continental areas were used to investigate the origin of island biodiversity and to compare patterns of colonization and differentiation. A comparative nucleotide substitution rate test was used to select the appropriate substitution rate to infer clade divergence times. RESULTS: Madeiran and Canarian Tarphius species were found to be more closely related to each other, while Azorean taxa grouped separately. Azorean taxa showed concordance between species and phylogenetic clades, except for species that occur on multiple islands, which segregated by island of origin. Divergence time estimates revealed that Azorean Tarphius are an old group and that the most recent intra-island speciation event on Santa Maria, the oldest island, occurred between 3.7 and 6.1 Ma. MAIN CONCLUSIONS: Our phylogenetic approach provides new evidence to understand the impoverishment of Azorean endemics: (1) Tarphius have had a long evolutionary history within the Azores, which does not support the hypothesis of fewer radiation events due to recent colonization; (2) the current taxonomy of Azorean Tarphius does not reflect common ancestry and cryptic speciation is responsible for the underestimation of endemics; (3) intra-island differentiation in the Azores was found only in the oldest island, supporting the idea that young geological age of the archipelago limits the number of endemics; and (4) the lack of evidence for recent intra-island diversification in Santa Maria could also explain the paucity of Azorean endemics. Phylogenetic reconstructions of other species-rich taxa that occur on multiple Macaronesian archipelagos will reveal whether our conclusions are taxon specific, or of a more general nature.