Pleistocene range shifts, refugia and the origin of widespread species in western Palaearctic water beetles

Abstract

Quaternary glacial cycles drove major shifts in both the extent and location of the geographical ranges of many organisms. During glacial maxima, large areas of central and northern Europe were inhospitable to temperate species, and these areas are generally assumed to have been recolonized during interglacials by range expansions from Mediterranean refugia. An alternative is that this recolonization was from non-Mediterranean refugia, in central Europe or western Asia, but data on the origin of widespread central and north European species remain fragmentary, especially for insects. We studied three widely distributed lineages of freshwater beetles (the Platambus maculatus complex, the Hydraena gracilis complex, and the genus Oreodytes), all restricted to running waters and including both narrowly distributed southern endemics and widespread European species, some with distributions spanning the Palearctic. Our main goal was to determine the role of the Pleistocene glaciations in shaping the diversification and current distribution of these lineages. We sequenced four mitochondrial and two nuclear genes in populations drawn from across the ranges of these taxa, and used Bayesian probabilities and Maximum Likelihood to reconstruct their phylogenetic relationships, age and geographical origin. Our results suggest that all extant species in these groups are of Pleistocene origin. In the H. gracilis complex, the widespread European H. gracilis has experienced a rapid, recent range expansion from northern Anatolia, to occupy almost the whole of Europe. However, in the other two groups widespread central and northern European taxa appear to originate from central Asia, rather than the Mediterranean. These widespread species of eastern origin typically have peripherally isolated forms in the southern Mediterranean peninsulas, which may be remnants of earlier expansion-diversification cycles or result from incipient isolation of populations during the most recent Holocene expansion. The accumulation of narrow endemics of such lineages in the Mediterranean may result from successive cycles of range expansion, with subsequent speciation (and local extinction in glaciated areas) through multiple Pleistocene climatic cycles.

Knitting patterns of biodiversity, range size and body size in aquatic beetle faunas: significant relationships but slightly divergent drivers

“…It is also likely that, as a result of warmer air and water temperatures, freshwater ecosystems in the southern part of the study area are much more productive that those in the northern parts, thereby providing more energy to support more species (Currie et al, 2004). This has been postulated to result from historical influences in southern faunas, which show relatively recent evolutionary changes and, in northern faunas, which have formed after the latest ice age (García-Vázquez et al, 2017). A large prey availability might thus account for the indirect effect of temperature on diving beetle species richness.…”

“…Calosi et al, 2010). This has been postulated to result from historical influences in southern faunas, which show relatively recent evolutionary changes and, in northern faunas, which have formed after the latest ice age (García-Vázquez et al, 2017). Hence, only species able to disperse across large geographical areas have reached the north and now comprise the northern faunas (Dehling et al, 2010;Gómez-Rodríguez & Baselga, 2018).…”

The effects of drift and selection on latitudinal genetic variation in Scandinavian common toads (Bufo bufo) following postglacial recolonisation

“…During the last glacial maximum (LGM), 23–18 Kya, northern Europe was covered by glacial ice that rendered the region undesirable, and most European animal and plant species had retreated to glacial refugia at lower latitudes in Europe and western Asia (e.g. Petit et al 2003 ; Hewitt 2004 ; Schmitt 2007 ; Recuero et al 2012 ; García-Vázquez et al 2017 ; Kühne et al 2017 ; Wielstra et al 2017 ). Hence, the genetic landscape of species inhabiting northern Europe has been shaped by both selection and drift in the different glacial refugia and along the different recolonisation routes (Eckert et al 2008 ; Hampe and Petit 2005 ; Guo 2012 ; Weir et al 2016 ).…”

Molecular phylogenetics and biogeography provide insights into the subgeneric classification of Wiedemannia Zetterstedt (Diptera: Empididae: Clinocerinae)

“…The complex patterns of geographic distribution within Wiedemannia suggest a complex evolutionary history of the genus, with different processes, such as range expansions and vicariant speciation, occurring repeatedly at different periods and parts of the range (e.g. Perea et al ., ; Ribera et al ., ; García‐Vázquez et al ., ). The major radiation into recognizably modern groups of Empididae most probably occurred in the early Cretaceous (Grimaldi & Cumming, ).…”