@article {1362, title = {Comparative phylogeography and speciation of dung beetles from the Australian Wet Tropics rainforest}, journal = {Molecular Ecology}, volume = {16}, number = {23}, year = {2007}, pages = {4984-4998}, abstract = {In tropical rainforests, insects show especially high species richness and local endemism of species relative to vertebrates. One possible cause is that insects respond to historical fluctuations of rainforests on a smaller spatial scale than do vertebrates. To evaluate this hypothesis, we combine environmental niche models and mitochondrial DNA phylo- geography for two pairs of sister species of the dung beetle genus Temnoplectron (T. aene- opiceum{\textendash}T. subvolitans and T. politulum{\textendash}T. reyi) from the rainforests of northeastern Australia, where climate-driven rainforest fluctuations in the Quaternary have strongly influenced genetic and species diversity of vertebrates. Within both species pairs, the bio- climatic niche was conserved, but the T. aeneopiceum{\textendash}T. subvolitans species pair had the narrower environmental range, and thus more restricted potential distribution. Coalescent analyses indicated Late Pliocene or Early Pleistocene divergences for both species pairs, and earlier speciation in (T. aeneopiceum{\textendash}T. subvolitans) than in (T. politulum{\textendash}T. reyi). Phylogeographic structure in (T. aeneopiceum{\textendash}T. subvolitans) was more pronounced than in (T. politulum{\textendash}T. reyi), with significant isolation-by-distance in the former species-pair only. Nested clade and coalescence analyses indicated local range expansions for the T. aeneopiceum{\textendash}subvolitans species pair and range-wide expansion for both T. politulum and T. reyi. We suggest that stronger phylogeographic structure and earlier divergence in (T. aeneopiceum{\textendash}T. subvolitans) than in (T. politulum{\textendash}T. reyi) reflects a stronger influence of environmental barriers to gene flow under the present climate and greater sensitivity to warmer and drier periods of the Quaternary. The two species pairs evidently responded to Quaternary rainforest fluctuations at spatial scales similar to those seen within low-vagility species of vertebrate. Despite this similarity of scale, these insect lineages are reproduc- tively isolated at parapatric boundaries, whereas analogous lineages of vertebrates often are not. We suggest that rapid evolution of genitalia may facilitate geographic speciation in rainforest beetles. }, keywords = {Dung beetles, mitochondrial DNA, phylogeography, speciation, Temnoplectron, tropical rainforest}, author = {Bell, Karen L. and Moritz, Craig and Moussalli, Adnan and Yeates, David K.} } @article {2162, title = {Spatial population structure in a patchily distributed beetle}, journal = {Molecular Ecology}, volume = {10}, year = {2001}, pages = {823-837}, abstract = {The dynamics and evolution of populations will critically depend on their spatial structure.Hence, a recent emphasis on one particular type of structure{\textemdash}the metapopulation conceptof Levins{\textemdash}can only be justified by empirical assessment of spatial population structuresin a wide range of organisms. This paper focuses onAphodius fossor, a dung beetle specializedon cattle pastures. An agricultural database was used to locate nearly 50 000 localpopulationsofA. fossorin Finland. Several independent methods were then used to quantify key processesin this vast population system.Allozyme markers and mitochondrial DNA (mtDNA)sequences were applied to examine genetic differentiation of local populations and to deriveindirect estimates of gene flow. These estimates were compared to values expected on thebasis of direct observations of dispersing individuals and assessments of local effectivepopulation size. Molecular markers revealed striking genetic homogeneity inA. fossor.Differentiation was only evident in mtDNA haplotype frequencies between the isolated{\r A}land islands and the Finnish mainland. Thus, indirect estimates of gene flow agreed withdirect observations that local effective population size inA. fossoris large (hundreds ofindividuals), and that in each generation, a substantial fraction (approximately one-fifth) ofthe individuals move between populations. Large local population size, extreme haplotypediversity and a high regional incidence ofA. fossorall testify against recurrent populationturnover. Taken together, these results provide strong evidence that the whole mainlandpopulation ofA. fossoris better described as one large {\textquoteleft}patchy population{\textquoteright}, with substantialmovement between relatively persistent local populations, than as a classical metapopulation.}, keywords = {allozymes, aphodius, gene flow, genetic differentiation, mitochondrial DNA, spatial population structure}, author = {Roslin, T.} }