Phylogeographic structure of the pygmy shrew: revisiting the roles of southern and northern refugia in Europe (original) (raw)
Related papers
Biological Journal of the Linnean Society, 2020
Southern and northern glacial refugia are considered paradigms that explain the complex phylogeographical patterns and processes of European biota. Here, we provide a revisited statistical phylogeographical analysis of the pygmy shrew Sorex minutus Linnaeus, 1766 (Eulipotyphla, Soricidae), examining its genetic diversity, genetic differentiation and demographic history in the Mediterranean peninsulas and in Western and Central Europe. The results showed support for genetically distinct and diverse phylogeographical groups consistent with southern and northern glacial refugia, as expected from previous studies. We also identified geographical barriers concordant with glaciated mountain ranges during the Last Glacial Maximum (LGM), early diversification events dated between the Late Pleistocene and Early Holocene for the main phylogeographical groups, and recent (post-LGM) patterns of demographic expansions. This study is the most comprehensive investigation of this species to date, a...
Ecography, 2000
The southern European peninsulas (Iberian, Italian and Balkan) are traditionally recognized as glacial refugia from where many species colonized central and northern Europe after the Last Glacial Maximum (LGM). However, evidence that some species had more northerly refugia is accumulating from phylogeographic, palaeontological and palynological studies, and more recently from species distribution modelling (SDM), but further studies are needed to test the idea of northern refugia in Europe. Here, we take a rarely implemented multidisciplinary approach to assess if the pygmy shrew Sorex minutus, a widespread Eurasian mammal species, had northern refugia during the LGM, and if these influenced its postglacial geographic distribution. First, we evaluated the phylogeographic and population expansion patterns using mtDNA sequence data from 123 pygmy shrews. Then, we used SDM to predict present and past (LGM) potential distributions using two different training data sets, two different algorithms (Maxent and GARP) and climate reconstructions for the LGM with two different general circulation models. An LGM distribution in the southern peninsulas was predicted by the SDM approaches, in line with the occurrence of lineages of S. minutus in these areas. The phylogeographic analyses also indicated a widespread and strictly northern-central European lineage, not derived from southern peninsulas, and with a postglacial population expansion signature. This was consistent with the SDM predictions of suitable LGM conditions for S. minutus occurring across central and eastern Europe, from unglaciated parts of the British Isles to much of the eastern European Plain. Hence, S. minutus likely persisted in parts of central and eastern Europe during the LGM, from where it colonized other northern areas during the late-glacial and postglacial periods. Our results provide new insights into the glacial and postglacial colonization history of the European mammal fauna, notably supporting glacial refugia further north than traditionally recognized.
2010
Here, I investigate the phylogeography and morphology of the Eurasian pygmy shrew Sorex minutus, searching for significantly differentiated lineages, colonisation routes and demographic parameters that would explain the effects of the Quaternary glaciations on the current distribution of the species. I also explore the genetic and morphological diversity and origin of pygmy shrew populations in the British Isles, particularly focusing on Ireland and the Orkney islands. Mitochondrial and nuclear DNA markers were used for the phylogeographic analyses, and a geometric morphometrics approach was implemented on mandible and skull samples. There was an evident phylogeographic structure across Eurasia consistent with occurrence of southern glacial refugia, and there were two distinct lineages in Northern-Central Europe and near the Pyrenees supporting the existence of northern glacial refugia through the characteristics of their distribution and population expansion. Haplotypes from Britai...
Biological Journal of The Linnean Society, 2010
At the Last Glacial Maximum (LGM), the southern European peninsulas were important refugia for temperate species. Current genetic subdivision of species within these peninsulas may reflect past population subdivision at the LGM, as in 'refugia within refugia', and/or at other time periods. In the present study, we assess whether pygmy shrew populations from different regions within Italy are genetically and morphologically distinct. One maternally and two paternally inherited molecular markers (cytochrome b and Y-chromosome introns, respectively) were analysed using several phylogenetic methods. A geometric morphometric analysis was performed on mandibles to evaluate size and shape variability between populations. Mandible shape was also explored with a functional approach that considered the mandible as a first-order lever affecting bite force. We found genetically and morphologically distinct European, Italian, and southern Italian groups. Mandible size increased with decreasing latitude and southern Italian pygmy shrews exhibited mandibles with the strongest bite force. It is not clear whether or not the southern Italian and Italian groups of pygmy shrews occupied different refugia within the Italian peninsula at the LGM. It is likely, however, that geographic isolation earlier than the LGM on islands at the site of present-day Calabria was important in generating the distinctive southern Italian group of pygmy shrews, and also the genetic groups in other small vertebrates that we review here. Calabria is an important hotspot for genetic diversity, and is worthy of conservation attention.
The aim of the present study was to investigate the genetic structure of the Valais shrew (Sorex antinorii) by a combined phylogeographical and landscape genetic approach, and thereby to infer the locations of glacial refugia and establish the influence of geographical barriers. We sequenced part of the mitochondrial cytochrome b (cyt b) gene of 179 individuals of S. antinorii sampled across the entire species' range. Six specimens attributed to S. arunchi were included in the analysis. The phylogeographical pattern was assessed by Bayesian molecular phylogenetic reconstruction, population genetic analyses, and a species distribution modelling (SDM)-based hindcasting approach. We also used landscape genetics (including isolation-by-resistance) to infer the determinants of current intra-specific genetic structure. The phylogeographical analysis revealed shallow divergence among haplotypes and no clear substructure within S. antinorii. The starlike structure of the median-joining network is consistent with population expansion from a single refugium, probably located in the Apennines. Long branches observed on the same network also suggest that another refugium may have existed in the north-eastern part of Italy. This result is consistent with SDM, which also suggests several habitable areas for S. antinorii in the Italian peninsula during the LGM. Therefore S. antinorii appears to have occupied disconnected glacial refugia in the Italian peninsula, supporting previous data for other species showing multiple refugia within southern refugial areas. By coupling genetic analyses and SDM, we were able to infer how past climatic suitability contributed to genetic divergence of populations. The genetic differentiation shown in the present study does not support the specific status of S. arunchi. P. 2006. Hares on thin ice: introgression of mitochondrial DNA in hares and its implications for recent phylogenetic analyses. Molecular Phylogenetics and Evolution 40: 640-641. Araújo MB, New M. 2007. Ensemble forecasting of species distributions. Trends in Ecology and Evolution 22: 42-47. Avise J. 2000. Phylogeography: the history and formation of species. Cambridge, MA: Harvard University Press. Bandelt H-J, Forster P, Röhl A. 1999. Median-joining networks for inferring intraspecific phylogenies. Molecular Biology and Evolution 16: 37-48. Basset P, Yannic G, Hausser J. 2006. Genetic and karyotypic structure in the shrews of the Sorex araneus group: are they independent? Molecular Ecology 15: 1577-1587. Bilton DT, Mirol PM, Mascheretti S, Fredga K, Zima J, Searle JB. 1998. Mediterranean Europe as an area of endemism for small mammals rather than a source for northwards postglacial colonization. Proceedings of the Royal Society of London Series B, Biological Sciences 265: 1219-1226. Brünner H, Lugon-Moulin N, Balloux F, Fumagalli L, Hausser J. 2002. A taxonomical re-evaluation of the Valais chromosome race of the common shrew Sorex araneus (Insectivora: Soricidae). Acta Theriologica 47: 245-275. Canestrelli D, Cimmaruta R, Nascetti G. 2007. Phylogeography and historical demography of the Italian treefrog, Hyla intermedia, reveals multiple refugia, population expansions and secondary contacts within peninsular Italy. Molecular Ecology 16: 4808-4482. Canestrelli D, Cimmaruta R, Nascetti G. 2008. Population genetic structure and diversity of the Apennine endemic stream frog, Rana italica -insights on the Pleistocene evolutionary history of the Italian peninsular biota. Molecular Ecology 17: 3856-3872.
Journal of …, 2007
We sequenced 1077 bp of the mitochondrial cytochrome b gene and 511 bp of the nuclear Apolipoprotein B gene in bicoloured shrew (Crocidura leucodon, Soricidae) populations ranging from France to Georgia. The aims of the study were to identify the main genetic clades within this species and the influence of Pleistocene climatic variations on the respective clades. The mitochondrial analyses revealed a European clade distributed from France eastwards to north-western Turkey and a Near East clade distributed from Georgia to Romania; the two clades separated during the Middle Pleistocene. We clearly identified a population expansion after a bottleneck for the European clade based on mitochondrial and nuclear sequencing data; this expansion was not observed for the eastern clade. We hypothesize that the western population was confined to a small Italo-Balkanic refugium, whereas the eastern population subsisted in several refugia along the southern coast of the Black Sea.
The aim of the present study was to investigate the genetic structure of the Valais shrew (Sorex antinorii) by a combined phylogeographical and landscape genetic approach, and thereby to infer the locations of glacial refugia and establish the influence of geographical barriers. We sequenced part of the mitochondrial cytochrome b (cyt b) gene of 179 individuals of S. antinorii sampled across the entire species' range. Six specimens attributed to S. arunchi were included in the analysis. The phylogeographical pattern was assessed by Bayesian molecular phylogenetic reconstruction, population genetic analyses, and a species distribution modelling (SDM)-based hindcasting approach. We also used landscape genetics (including isolation-by-resistance) to infer the determinants of current intra-specific genetic structure. The phylogeographical analysis revealed shallow divergence among haplotypes and no clear substructure within S. antinorii. The starlike structure of the median-joining network is consistent with population expansion from a single refugium, probably located in the Apennines. Long branches observed on the same network also suggest that another refugium may have existed in the north-eastern part of Italy. This result is consistent with SDM, which also suggests several habitable areas for S. antinorii in the Italian peninsula during the LGM. Therefore S. antinorii appears to have occupied disconnected glacial refugia in the Italian peninsula, supporting previous data for other species showing multiple refugia within southern refugial areas. By coupling genetic analyses and SDM, we were able to infer how past climatic suitability contributed to genetic divergence of populations. The genetic differentiation shown in the present study does not support the specific status of S. arunchi. P. 2006. Hares on thin ice: introgression of mitochondrial DNA in hares and its implications for recent phylogenetic analyses. Molecular Phylogenetics and Evolution 40: 640-641. Araújo MB, New M. 2007. Ensemble forecasting of species distributions. Trends in Ecology and Evolution 22: 42-47. Avise J. 2000. Phylogeography: the history and formation of species. Cambridge, MA: Harvard University Press. Bandelt H-J, Forster P, Röhl A. 1999. Median-joining networks for inferring intraspecific phylogenies. Molecular Biology and Evolution 16: 37-48. Basset P, Yannic G, Hausser J. 2006. Genetic and karyotypic structure in the shrews of the Sorex araneus group: are they independent? Molecular Ecology 15: 1577-1587. Bilton DT, Mirol PM, Mascheretti S, Fredga K, Zima J, Searle JB. 1998. Mediterranean Europe as an area of endemism for small mammals rather than a source for northwards postglacial colonization. Proceedings of the Royal Society of London Series B, Biological Sciences 265: 1219-1226. Brünner H, Lugon-Moulin N, Balloux F, Fumagalli L, Hausser J. 2002. A taxonomical re-evaluation of the Valais chromosome race of the common shrew Sorex araneus (Insectivora: Soricidae). Acta Theriologica 47: 245-275. Canestrelli D, Cimmaruta R, Nascetti G. 2007. Phylogeography and historical demography of the Italian treefrog, Hyla intermedia, reveals multiple refugia, population expansions and secondary contacts within peninsular Italy. Molecular Ecology 16: 4808-4482. Canestrelli D, Cimmaruta R, Nascetti G. 2008. Population genetic structure and diversity of the Apennine endemic stream frog, Rana italica -insights on the Pleistocene evolutionary history of the Italian peninsular biota. Molecular Ecology 17: 3856-3872.
2006
We sequenced 998 base pairs (bp) of mitochondrial DNA cytochrome b and 799 bp of nuclear gene BRCA1 in the Lesser white-toothed shrew (Crocidura suaveolens group) over its geographic range from Portugal to Japan. The aims of the study were to identify the main clades within the group and respective refugia resulting from Pleistocene glaciations. Analyses revealed the Asian lesser white-toothed shrew (C. shantungensis) as the basal clade, followed by a major branch of C. suaveolens, subdivided sensu stricto into six clades, which split-up in the Upper Pliocene and Lower Pleistocene (1.9-0.9 Myr). The largest clade, occurring over a huge range from east Europe to Mongolia, shows evidence of population expansion after a bottleneck. West European clades originated from Iberian and Italo-Balkanic refugia. In the Near East, three clades evolved in an apparent hotspot of refugia (west Turkey, south-west and south-east of the Caucasus). Most clades include specimens of diVerent morphotypes and the validity of many taxa in the C. suaveolens group has to be re-evaluated.
Molecular Phylogenetics and Evolution, 2006
We sequenced 998 base pairs (bp) of mitochondrial DNA cytochrome b and 799 bp of nuclear gene BRCA1 in the Lesser white-toothed shrew (Crocidura suaveolens group) over its geographic range from Portugal to Japan. The aims of the study were to identify the main clades within the group and respective refugia resulting from Pleistocene glaciations. Analyses revealed the Asian lesser white-toothed shrew (C. shantungensis) as the basal clade, followed by a major branch of C. suaveolens, subdivided sensu stricto into six clades, which split-up in the Upper Pliocene and Lower Pleistocene (1.9-0.9 Myr). The largest clade, occurring over a huge range from east Europe to Mongolia, shows evidence of population expansion after a bottleneck. West European clades originated from Iberian and Italo-Balkanic refugia. In the Near East, three clades evolved in an apparent hotspot of refugia (west Turkey, south-west and south-east of the Caucasus). Most clades include specimens of diVerent morphotypes and the validity of many taxa in the C. suaveolens group has to be re-evaluated.
Research Square (Research Square), 2023
The pigmy white-toothed shrew Suncus etruscus is a widespread species whose distribution patterns are unclear. Paleontological data suggested an east-west pattern of dispersion in the Mediterranean basin during late Holocene but some doubts are still present especially considering the absence of fossil remains from key areas, as mainland Italy. Here we propose, a preliminary screening of the phylogeographic relationships among Italian pigmy white-toothed shrews and other Mediterranean areas. The Italian haplotypes were all very similar without an evident geographic structure, however we evidenced that the haplotype from Israel, the putative source area for the Mediterranean basin, is almost identical to the most common Italian haplotype. This excludes an ancient event of vicariance between the two areas and we can assume that these haplotypes arrived in the central Mediterranean through the eastward wave of colonization, in agreement with the relatively recent arrival of the species in the area.