Molecular phylogeny and timing of diversification in Alpine Rhithrogena (Ephemeroptera: Heptageniidae)

BMC Evolutionary Biology

Research Article

Michael T. Monaghan¹  Sereina Rutschmann²  Michel Sartori³  Laurent Vuataz³ 

[1] Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), 12587, Berlin, Germany;Berlin Center for Genomics in Biodiversity Research, 14195, Berlin, Germany;Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), 12587, Berlin, Germany;Berlin Center for Genomics in Biodiversity Research, 14195, Berlin, Germany;Department of Biochemistry, Genetics and Immunology, University of Vigo, 36310, Vigo, Spain;Musée cantonal de zoologie, Palais de Rumine, Place de la Riponne 6, 1014, Lausanne, Switzerland;Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland;

关键词: Dated phylogeny;    Speciation;    Diversification;    Lineage-through-time;    Pleistocene glaciations;    Freshwater insects;    Headwater;    Mayfly;    Ephemeroptera;   

DOI  :  10.1186/s12862-016-0758-1

 received in 2016-08-31, accepted in 2016-09-01,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundLarvae of the Holarctic mayfly genus Rhithrogena Eaton, 1881 (Ephemeroptera, Heptageniidae) are a diverse and abundant member of stream and river communities and are routinely used as bio-indicators of water quality. Rhithrogena is well diversified in the European Alps, with a number of locally endemic species, and several cryptic species have been recently detected. While several informal species groups are morphologically well defined, a lack of reliable characters for species identification considerably hampers their study. Their relationships, origin, timing of speciation and mechanisms promoting their diversification in the Alps are unknown.ResultsHere we present a species-level phylogeny of Rhithrogena in Europe using two mitochondrial and three nuclear gene regions. To improve sampling in a genus with many cryptic species, individuals were selected for analysis according to a recent DNA-based taxonomy rather than traditional nomenclature. A coalescent-based species tree and a reconstruction based on a supermatrix approach supported five of the species groups as monophyletic. A molecular clock, mapped on the most resolved phylogeny and calibrated using published mitochondrial evolution rates for insects, suggested an origin of Alpine Rhithrogena in the Oligocene/Miocene boundary. A diversification analysis that included simulation of missing species indicated a constant speciation rate over time, rather than any pronounced periods of rapid speciation. Ancestral state reconstructions provided evidence for downstream diversification in at least two species groups.ConclusionsOur species-level analyses of five gene regions provide clearer definitions of species groups within European Rhithrogena. A constant speciation rate over time suggests that the paleoclimatic fluctuations, including the Pleistocene glaciations, did not significantly influence the tempo of diversification of Alpine species. A downstream diversification trend in the hybrida and alpestris species groups supports a previously proposed headwater origin hypothesis for aquatic insects.

【 授权许可】

CC BY   
© The Author(s). 2016