Ecological niche and phylogeography elucidate complex biogeographic patterns in Loxosceles rufescens (Araneae, Sicariidae) in the Mediterranean Basin

Abstract

BackgroundUnderstanding the evolutionary history of morphologically cryptic species complexes is difficult, and made even more challenging when geographic distributions have been modified by human-mediated dispersal. This situation is common in the Mediterranean Basin where, aside from the environmental heterogeneity of the region, protracted human presence has obscured the biogeographic processes that shaped current diversity. Loxosceles rufescens (Araneae, Sicariidae) is an ideal example: native to the Mediterranean, the species has dispersed worldwide via cohabitation with humans. A previous study revealed considerable molecular diversity, suggesting cryptic species, but relationships among lineages did not correspond to geographic location.ResultsDelimitation analyses on cytochrome c oxidase subunit I identified 11 different evolutionary lineages, presenting two contrasting phylogeographic patterns: (1) lineages with well-structured populations in Morocco and Iberia, and (2) lineages lacking geographic structure across the Mediterranean Basin. Dating analyses placed main diversification events in the Pleistocene, and multiple Pleistocene refugia, identified using ecological niche modeling (ENM), are compatible with allopatric differentiation of lineages. Human-mediated transportation appears to have complicated the current biogeography of this medically important and synanthropic spider.ConclusionsWe integrated ecological niche models with phylogeographic analyses to elucidate the evolutionary history of L. rufescens in the Mediterranean Basin, with emphasis on the origins of mtDNA diversity. We found support for the hypothesis that northern Africa was the center of origin for L. rufescens, and that current genetic diversity originated in allopatry, likely promoted by successive glaciations during the Pleistocene. We corroborated the scenario of multiple refugia within the Mediterranean, principally in northern Africa, combining results from eight atmosphere–ocean general circulation models (AOGCMs) with two different refugium-delimitation methodologies. ENM results were useful for providing general views of putative refugia, with fine-scale details depending on the level of stringency applied for agreement among models.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-014-0195-y) contains supplementary material, which is available to authorized users.

Intraspecific genetic structure, divergence and high rates of clonality in an amphi‐Atlantic starfish

“…Nevertheless, the presence of only a few "admixed" genotypes in 2. Our results demonstrate that asexual reproduction is common in C. tenuispina, as observed by the presence of clones and significant excess of heterozygotes (Balloux et al, 2003;de Meeûs et al, 2007) We also observe that the Canary Islands retained the highest values of genetic diversity and number of genotypes, which is a characteristic sign of central geographical distribution Ehrich, Alsos, & Brochmann, 2008;Planas, Saupe, Lima-Ribeiro, Peterson, & Ribera, 2014).…”

“…We also observe that the Canary Islands retained the highest values of genetic diversity and number of genotypes, which is a characteristic sign of central geographical distribution (Besnard, El Bakkali et al., ; Besnard, Khadari et al., ; Ehrich, Alsos, & Brochmann, ; Planas, Saupe, Lima‐Ribeiro, Peterson, & Ribera, ). Additionally, the presence of “admixed” genotypes in most locations of the Canary Islands observed in structure (Figure d) is indicative of recombination during sexual reproduction.…”

Media representation of spiders may exacerbate arachnophobic sentiments by framing a distorted perception of risk

“…Loxosceles rufescens is native to the Mediterranean basin (Planas, Saupe, Lima-Ribeiro, Peterson, & Ribera, 2014), but has been introduced to many areas of the world where it is considered an important invasive species (Nentwig, Pantini, & Vetter, 2017; Taucare-Rios, Nentwig, Bizama, & Bustamante, 2018). The Mediterranean recluse is a rather common inhabitant of natural and in-door habitats in Italy and thus, it seems likely that it has been coexisting with humans for centuries.…”

Subterranean termite phylogeography reveals multiple postglacial colonization events in southwestern Europe

“…This refugium is further to the north and east that what proposed by Kutnik et al (2004) suggesting the Andalusia refugium was a separate southern refugium. The genetic relationships among termites from the nearby Balearic Archipelago merits investigation as gene flow between these islands and the Iberian Peninsula could explain the high level of genetic diversity detected at site L. Moreover, the Balearic Islands could also have been glacial refugia (L opez de Heredia et al 2007;Planas et al 2014).…”