Testing Phylogeographic Hypotheses in a Euro-Siberian Cold-Adapted Leaf Beetle With Coalescent Simulations

Abstract

Few studies to date have investigated the impact of Pleistocene climatic oscillations on the genetic diversity of cold-adapted species.We focus on the geographic distribution of genetic diversity in a Euro-Siberian boreo-montane leaf beetle, Gonioctena pallida.We present the molecular variation from three independent gene fragments over the entire geographic range of this insect. The observed sequence variation identifies a genetic diversity hot spot in the Carpathian Mountains, in central Europe, which reveals the presence of (1) an ancestral refuge population or (2) a secondary contact zone in this area. Modeling of population evolution in a coalescent framework allowed us to favor the ancestral refuge hypothesis. These analyses suggest that the Carpathian Mountains served as a refuge for G. pallida, whereas the rest of the species distribution, that spans a large portion of Europe and Asia, experienced a dramatic reduction in genetic variation probably associated to bottlenecks and/or founder events. We estimated the time of isolation of the ancestral refuge population, using an approximate Bayesian method, to be larger than 90,000 years. If true, the current pattern of genetic variation in this cold-adapted organism was shaped by a climatic event predating by far the end of the last ice age.

The diversity and biogeography of the Coleoptera of Churchill: insights from DNA barcoding

“…Furthermore, the loss of genetic diversity in populations of both open ground and boreal forest species could seriously affect their ability to adapt to both present and future change. Open-ground species could be negatively affected by the combination of founder bottlenecks and retreat of the southern boundary of their distributions, even as suitable habitat expands to the north [13,68,69]. Similarly, changes at the southern edge of the distribution of forest-dwelling species may lead to fragmentation of the habitat and coincident loss of overall genetic diversity in the biogeographic center of distribution.…”

Climate Change and Evolutionary Adaptations at Species' Range Margins

“…This is particularly the case for species that are adapted to cool environments and would, in many cases, have been more widespread during glacial climates; their current distributions may represent Holocene (interglacial) refugia. For example, the coldadapted European leaf beetle Gonioctena pallida has a hotspot of genetic diversity in the Carpathian Mountains in central Europe, which implies that current patterns of genetic variation in this species reflect a Pleistocene climatic event that resulted in population isolation >90,000 years ago, well before the end of the last ice age (78). Other studies demonstrate evidence of repeated glacial/interglacial cycles on current patterns of genetic diversity, with likely range expansion during glacial periods (25).…”

“…Some studies have shown that spatial patterns of genetic diversity reflect the existence of more ancient refugia that predate the last glacial period (78). This is particularly the case for species that are adapted to cool environments and would, in many cases, have been more widespread during glacial climates; their current distributions may represent Holocene (interglacial) refugia.…”

Molecular Biogeography of the High Mountain Systems of Europe: An Overview

“…they are derived from the same refugia as the nearby Alpine populations (e.g. Pauls et al 2006;Schmitt et al 2006;Mardulyn et al 2009;Triponez et al 2011;Alvarez et al 2012;Charrier et al 2014). Exceptions to this rule are the caddisfly Drusus discolor with a genetic lineage restricted to Jura, Vosges and Black Forest (Pauls et al 2006) and the butterfly Erebia manto with the genetically strongly differentiated taxon vogesiaca endemic to the Vosges (Schmitt et al 2014).…”