22 results on '"fragmented distribution"'
Search Results
2. Phylogenetics and population structure of the steppe species Hycleus polymorphus (Coleoptera: Meloidae: Mylabrini) reveal multiple refugia in Mediterranean mountain ranges.
- Author
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Riccieri, Alessandra, Mancini, Emiliano, Iannella, Mattia, Salvi, Daniele, and Bologna, Marco A
- Subjects
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MOUNTAINS , *GEOGRAPHICAL distribution of insects , *PHYLOGEOGRAPHY , *STEPPES , *NUCLEAR DNA , *SPECIES distribution , *GLACIATION - Abstract
Many continental species distributed in the Eurasian steppe occur as relict populations in the mountains of Western Europe. Their biogeographical responses to Quaternary climate changes have been poorly studied; however, they could have responded as cold-adapted species. We investigated the biogeographic history of a steppe beetle, Hycleus polymorphus , using mitochondrial and nuclear DNA sequences (COI , CAD , ITS2), and species distribution modelling (SDM) under present and past bioclimatic envelopes. We first performed a phylogenetic assessment to define species boundaries within the H. polymorphus species group. Specimens previously treated as Hycleus humerosus on morphological grounds are assigned to H. polymorphus , and those identified as Hycleus zebraeus assigned to Hycleus atratus. ITS2 data analyses revealed a strong phylogeographical structure of H. polymorphus populations, with four haplogroups corresponding to the (i) Italian Alps, (ii) French Alps and Pyrenees, (iii) South Balkan and Pontic mountains, and (iv) North Dinaric Alps. Based on these analyses and the SDM, we propose that during a glacial period, following the spread of steppic habitat, H. polymorphus underwent a range expansion from Asia to South-West Europe. Within the Mediterranean area, during the last interglacial the climatic suitability for the species was limited to mountains that acted as refugia and prompted allopatric divergence into four main lineages. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
3. FIRST RECORD OF PHYSICULUS DALWIGKI (ACTINOPTERYGII: GADIFORMES: MORIDAE) FROM THE TUNISIAN COAST (CENTRAL MEDITERRANEAN SEA).
- Author
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CAPAPÉ, Christian, RAFRAFI-NOUIRA, Sihem, DIATTA, Youssouph, and REYNAUD, Christian
- Subjects
ACTINOPTERYGII ,COASTS ,SEAS ,STRAITS ,RECORDS - Abstract
A specimen of Physiculus dalwigki Kaup, 1758 measuring 218 mm in total length, 190 mm in standard length, and weighing 90 g was caught off the northern Tunisian coast. This capture constitutes the first record of this fish from the Tunisian coast. The specimen is described including morphological measurements, meristic counts, and color. Due to a lack of records, the real status of the species in the Tunisian waters still remains questionable. Physiculus dalwigki occurs only off northern Spain and south to the Strait of Gibraltar in the waters surrounding Madera and the Azores Islands, and in the Mediterranean Sea from Nice (southern France) to the Tunisian coast. Therefore, it appears that P. dalwigki is displaying a disjoint distribution with the exclusion of a large western region of the Mediterranean Sea. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
4. Phylogeographic insights into Artemisia crithmifolia (Asteraceae) reveal several areas of the Iberian Atlantic coast as refugia for genetic diversity.
- Author
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García-Fernández, Alfredo, Vitales, Daniel, Pellicer, Jaume, Garnatje, Teresa, and Vallès, Joan
- Subjects
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ASTERACEAE , *PHYLOGEOGRAPHY , *PLANT genetics , *PLASTIDS - Abstract
The study of fragmentation processes should be tackled using different approaches, in order to obtain solid and robust evidence that could help in identifying potential barriers and threats for species. In this study, we have evaluated the spatial fragmentation patterns in Artemisia crithmifolia (Asteraceae) along its current distribution along the Atlantic coastlines of Europe, from Portugal to the Netherlands and the UK. Niche modelling analyses considering current and past climatic conditions, combined with plastid markers, have been used to evaluate the disconnected distribution pattern of the species, genetic flow between populations and habitat suitability for present and past populations. Plastid markers showed very low variability, while suggesting that the westernmost populations from the Atlantic coast of the Iberian Peninsula are partially genetically isolated, due to the existence of a potential barrier for gene flow on the northern Spanish coast. However, niche models identify this area as a potential habitat for the species, even during the last glacial maximum (20,000 years ago). The combination of both techniques allows identification of potential refugia for the species, highlighting the most likely recolonisation routes and distribution patterns which resulted in the overall low levels of genetic diversity. Anthropogenic activities (urban sprawl, beach expansions, etc.) are most likely behind local extinctions, thus preventing the establishment and expansion of new populations. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
5. Uncovering environmental, land-use and fire effects on the distribution of a low-dispersal species, the Hermann's tortoise Testudo hermanni.
- Author
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Badiane, Arnaud, Matos, Cátia, and Santos, Xavier
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HERMANN'S tortoise , *LAND use , *DISPERSAL (Ecology) , *HABITAT destruction , *ANIMAL species , *WILDFIRES - Abstract
Habitat destruction has resulted in the fragmented distribution of numerous terrestrial species, which poses a challenge for conservationists. Furthermore, species management can be further compounded by life history constraints such as low dispersal, hindering the ability of species to recolonize areas they formerly occupied. For these species, a thorough understanding of the local threats and factors that limit their distribution is crucial for effective management. We used occupancy models to examine which factors at landscape and habitat scales (i.e. land uses, fire history, and vegetation structure) explain the presence of terrestrial tortoises within the range of the westernmost isolated population of the endangered Testudo hermanni hermanni in the Albera Range (NE of the Iberian Peninsula). We randomly surveyed 25 sites (75% of the area known with presence of tortoises) of natural woodlands with 5 to 8 replicates per site in spring 2012-2014. From a sampling effort of 148 hours, we only detected 52 tortoises in 12 of 25 transects. These low numbers are evidence of low population densities. Sites with presence of tortoises were spatially aggregated although the species was absent from apparently adequate sites on the edges of its distribution range. Current and historic land-use primarily explained the presence of tortoises. Besides, wildfires and reduction of habitat complexity also participate to explain the distribution of Hermann's tortoises. We also discuss some aspects of the conservation of Testudo hermanni in relation to our results. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
6. First record of Physiculus dalwigki (Actinopterygii: Gadiformes: Moridae) from the Tunisian coast (central Mediterranean Sea)
- Author
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Christian Capapé, Reynaud Christian, Diatta Youssouph, and Rafrafi-Nouira Sihem
- Subjects
biology ,Gadiformes ,Actinopterygii ,deep waters ,Aquatic Science ,morphometric measurements ,biology.organism_classification ,Moridae ,Mediterranean sea ,Geography ,Oceanography ,meristic counts ,Physiculus ,description ,fragmented distribution - Abstract
A specimen of Physiculus dalwigki Kaup, 1758 measuring 218 mm in total length, 190 mm in standard length, and weighing 90 g was caught off the northern Tunisian coast. This capture constitutes the first record of this fish from the Tunisian coast. The specimen is described including morphological measurements, meristic counts, and color. Due to a lack of records, the real status of the species in the Tunisian waters still remains questionable. Physiculus dalwigki occurs only off northern Spain and south to the Strait of Gibraltar in the waters surrounding Madera and the Azores Islands, and in the Mediterranean Sea from Nice (southern France) to the Tunisian coast. Therefore, it appears that P. dalwigki is displaying a disjoint distribution with the exclusion of a large western region of the Mediterranean Sea.
- Published
- 2020
7. Sand grain size composition influences subsurface oxygen diffusion and distribution of an endemic, psammophilic lizard.
- Author
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Ryberg, W. A. and Fitzgerald, L. A.
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SAND , *MINERAL aggregates , *GRAIN size , *MICROSTRUCTURE , *LIZARDS - Abstract
Reptile species endemic to dune ecosystems worldwide possess morphological and behavioral adaptations for burying in sand. Specializations for burying and subsurface breathing among these animals are advantageous only where sand conditions permit. The patchy distributions of many psammophilic species are presumably due to the occurrence of suitable areas where attributes of the sand facilitate locomotion, burying, subsurface breathing and nesting. The endemic, dune-dwelling S celoporus arenicolus does not occur in areas where sand grain size composition is relatively fine, and the distribution of the species appears limited to areas with coarse-grained sand. However, the exact mechanism by which this occurs is unknown. We hypothesized that subsurface breathing is inhibited in fine sand, and tested the prediction that fine sand restricts diffusion of oxygen. We compared oxygen diffusion rates in sand with grain size compositions matching sites where S . arenicolus was present (coarse sand) to diffusion rates in samples from sites where it was absent (fine sand). We found that samples with relatively coarse sand from sites where S . arenicolus was present had higher oxygen diffusion rates than samples with finer sand where S . arenicolus was absent. These results corroborated our prediction and support the hypothesis that subsurface breathing by S . arenicolus is constrained by fine sand. This is the first step in a line of research on the role of sand grain size composition in the life history of dune-dwelling reptiles and more experiments can build on this study. Our results have broad implications for the conservation of all strictly psammophilic species by improving our understanding of the habitat elements necessary for their survival and persistence. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
8. Molecular Species Delimitation of Larks (Aves: Alaudidae), and Integrative Taxonomy of the Genus Calandrella, with the Description of a Range-Restricted African Relic Taxon
- Author
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Stervander, Martin, Hansson, Bengt, Olsson, Urban, Hulme, Mark F., Ottosson, Ulf, Alström, Per, Stervander, Martin, Hansson, Bengt, Olsson, Urban, Hulme, Mark F., Ottosson, Ulf, and Alström, Per
- Abstract
Larks constitute an avian family of exceptional cryptic diversity and striking examples of convergent evolution. Therefore, traditional morphology-based taxonomy has recurrently failed to reflect evolutionary relationships. While taxonomy ideally should integrate morphology, vocalizations, behaviour, ecology, and genetics, this can be challenging for groups that span several continents including areas that are difficult to access. Here, we combine morphometrics and mitochondrial DNA to evaluate the taxonomy of Calandrella larks, with particular focus on the African C. cinerea and the Asian C. acutirostris complexes. We describe a new range-restricted West African taxon, Calandrella cinerea rufipecta ssp. nov. (type locality: Jos, Plateau State, Nigeria), with an isolated relic population 3000 km from its closest relative in the Rift Valley. We performed molecular species delimitation, employing coalescence-based multi-rate Poisson Tree Processes (mPTP) on cytochrome b sequences across 52 currently recognized lark species, including multiple taxa currently treated as subspecies. Three species-level splits were inferred within the genus Calandrella and another 13 across other genera, primarily among fragmented sub-Saharan taxa and taxa distributed from Northwest Africa to Arabia or East Africa. Previously unknown divergences date back as far as to the Miocene, indicating the presence of currently unrecognized species. However, we stress that taxonomic decisions should not be based on single datasets, such as mitochondrial DNA, although analyses of mitochondrial DNA can be a good indicator of taxa in need of further integrative taxonomic assessment.
- Published
- 2020
- Full Text
- View/download PDF
9. Phylogeography and population structure of Squalius lucumonis: A baseline for conservation of an Italian endangered freshwater fish
- Author
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Valentina Milana, Anna Rita Rossi, Simone Crescenzo, Lorenzo Tancioni, Antonella Carosi, Gerardo Petrosino, Massimo Lorenzoni, Lorenzo Talarico, Marco Martinoli, Luca Ciuffardi, and Arnold Rakaj
- Subjects
education.field_of_study ,Genetic diversity ,Brook chub ,Ecology ,biology ,Settore BIO/07 ,Population ,Endangered species ,Leuciscidae ,biology.organism_classification ,brook chub ,genetic diversity ,fragmented distribution ,endemic species ,management ,leuciscidae ,Fragmented distribution ,Brook chub, Genetic diversity, Fragmented distribution, Endemic species, Management, Leuciscidae ,Management ,Critically endangered ,Geography ,Genetic structure ,Squalius lucumonis ,IUCN Red List ,Endemic species ,education ,Nature and Landscape Conservation ,Isolation by distance - Abstract
The brook chub (Squalius lucumonis) is a freshwater fish, endemic of Central Italy, which is experiencing a rapid range decline so that it is presently listed as Critically Endangered in the Italian IUCN Red List. For effective conservation, information about the spatial pattern of genetic diversity is crucial. Therefore, we analysed the mitochondrial Control Region and nuclear (microsatellites) markers to investigate population genetic structure, demography and spatial diversity over the whole species distribution range. We revealed significant divergence among populations, even at the local spatial scale, according to the isolation by distance model. At the biogeographic spatial scale, genetic diversity was shaped by past hydrogeological and climatic events that isolated the principal drainage basins (Vara, Tiber and Arno) from each other. On the other hand, strong genetic differentiation within the Tiber drainage basin could be due to local factors that acted at single-stream scale, as recent barriers to fish dispersal and irregular seasonal flow rates typical of small Mediterranean streams. Our findings contribute to the basal data collection on S. lucumonis required by European Habitats Directive and necessary for planning protection actions. We recommend that the three river drainages and most of the sampling sites should be regarded as different Management Units (MUs) to preserve their genetic distinctiveness. A recovery plan for the brook chub should consider environmental intervention and creation of protected areas, as well as in situ/ex situ restocking activities with juveniles produced by breeders from the same MU, to preserve local (adaptive) diversity.
- Published
- 2021
10. Patterns of geographic distribution have a considerable influence on population genetic structure in one common and two rare species of Rhododendron (Ericaceae).
- Author
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Yoichi, Watanabe and Tomaru, Nobuhiro
- Subjects
POPULATION genetics ,RHODODENDRONS ,SPECIES ,ALLELES ,MICROSATELLITE repeats - Abstract
Genetic diversity is essential for species to sustain their populations and evolutionary potential. In order to develop effective conservation strategies for rare species, it is necessary to understand differences in patterns of genetic diversity between common and rare species. Data about population genetic structure is important to design effective conservation strategies for rare species. In this study, we compared the genetic diversity and population genetic structure of a common species, Rhododendron weyrichii, to those of two rare species, Rhododendron sanctum and Rhododendron amagianum, with different geographic distributions. We analyzed five microsatellite loci in 16 populations of R. weyrichii, 9 populations of R. sanctum, and 6 populations of R. amagianum. As expected, the level of genetic diversity indicated by allelic richness and gene diversity was lower for the rare species R. sanctum than for the common species R. weyrichii. However, there was no statistically significant difference in genetic diversity between R. weyrichii and the other rare species, R. amagianum. Analyses of the isolation-by-distance pattern, neighbor-joining trees, and Bayesian clustering indicated that R. sanctum had a strong population genetic structure whereas R. amagianum exhibited very weak genetic structure among populations and that there was moderate population genetic structure for R. weyrichii. Therefore, the degree and pattern of population genetic structure in each species was unrelated to its rarity and instead merely reflected its geographic distribution. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
11. Phylogenetics and population structure of the steppe species Hycleus polymorphus (Coleoptera: Meloidae: Mylabrini) reveal multiple refugia in Mediterranean mountain ranges
- Author
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Emiliano Mancini, Alessandra Riccieri, Mattia Iannella, Daniele Salvi, Marco Alberto Bologna, Riccieri, Alessandra, Mancini, Emiliano, Iannella, Mattia, Salvi, Daniele, and Bologna, MARCO A.
- Subjects
0106 biological sciences ,Mediterranean climate ,Steppe ,Species Distribution Models ,Population structure ,ITS2 ,phylogeography ,010603 evolutionary biology ,01 natural sciences ,COI ,03 medical and health sciences ,Phylogenetics ,CAD ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,0303 health sciences ,geography ,geography.geographical_feature_category ,biology ,Ecology ,Mediterranean mountains ,Pleistocene climate oscillations ,biology.organism_classification ,CAD, COI, cold-adapted species, continental elements, fragmented distribution, ITS2, Mediterranean mountains, phylogeography, Pleistocene climate oscillations, Species Distribution Model ,Polymorphus ,Phylogeography ,continental elements ,cold-adapted species ,fragmented distribution - Abstract
Many continental species distributed in the Eurasian steppe occur as relict populations in the mountains of Western Europe. Their biogeographical responses to Quaternary climate changes have been poorly studied; however, they could have responded as cold-adapted species. We investigated the biogeographic history of a steppe beetle, Hycleus polymorphus, using mitochondrial and nuclear DNA sequences (COI, CAD, ITS2), and species distribution modelling (SDM) under present and past bioclimatic envelopes. We first performed a phylogenetic assessment to define species boundaries within the H. polymorphus species group. Specimens previously treated as Hycleus humerosus on morphological grounds are assigned to H. polymorphus, and those identified as Hycleus zebraeus assigned to Hycleus atratus. ITS2 data analyses revealed a strong phylogeographical structure of H. polymorphus populations, with four haplogroups corresponding to the (i) Italian Alps, (ii) French Alps and Pyrenees, (iii) South Balkan and Pontic mountains, and (iv) North Dinaric Alps. Based on these analyses and the SDM, we propose that during a glacial period, following the spread of steppic habitat, H. polymorphus underwent a range expansion from Asia to South-West Europe. Within the Mediterranean area, during the last interglacial the climatic suitability for the species was limited to mountains that acted as refugia and prompted allopatric divergence into four main lineages.
- Published
- 2020
12. First record of little sleeper shark, Somniosus rostratus (Elasmobranchii: Squaliformes: Somniosidae), from the Tunisian coast, central Mediterranean Sea
- Author
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Diatta Youssouph, Christian Reynaud, Rafrafi-Nouira Sihem, and Capapé Christian
- Subjects
Somniosus rostratus ,nursery grounds ,biology ,Somniosidae ,Aquatic Science ,biology.organism_classification ,morphometric measurements ,Fishery ,Squaliformes ,Geography ,Mediterranean sea ,Elasmobranchii ,dental formula ,description ,fragmented distribution ,deep bottoms - Abstract
The first record of the little sleeper shark, Somniosus rostratus (Risso, 1827), from the Tunisian coast, is presented in this note. It was an adult female measuring 990 mm total length and weighing 4500 g. The capture occurred off Ras Jebel located in north-eastern Tunisia at a depth of 120 m. The specimen is herein described including morphological measurements, color, and dental formula. Due to a lack of records, the real status of the species in the Mediterranean Sea remains questionable. Somniosus rostratus is rarely caught in this sea because it lives in deep bottoms poorly exploited by commercial vessels. However, recent captures of specimens and occurrence of nursery grounds suggest that a viable population of S. rostratus is probably established in this sea.
- Published
- 2020
13. Stepping-stone expansion and habitat loss explain a peculiar genetic structure and distribution of a forest insect.
- Author
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Cassel ‐ Lundhagen, Anna, Ronnås, Cecilia, Battisti, Andrea, Wallén, Johan, and Larsson, Stig
- Subjects
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FOREST insects , *GEOGRAPHICAL distribution of insects , *HABITATS , *COLONIZATION (Ecology) , *DISPERSAL of insects - Abstract
It is challenging to unravel the history of organisms with highly scattered populations. Such species may have fragmented distributions because extant populations are remnants of a previously more continuous range, or because the species has narrow habitat requirements in combination with good dispersal capacity (naturally or vector borne). The northern pine processionary moth Thaumetopoea pinivora has a scattered distribution with fragmented populations in two separate regions, northern and south-western Europe. The aims of this study were to explore the glacial and postglacial history of T. pinivora, and add to the understanding of its current distribution and level of contemporary gene flow. We surveyed published records of its occurrence and analysed individuals from a representative subset of populations across the range. A 633 bp long fragment of the mt DNA COI gene was sequenced and nine polymorphic microsatellite loci were genotyped. Only nine nucleotide sites were polymorphic in the COI gene and 90% of the individuals from across its whole range shared the same haplotype. The microsatellite diversity gradually declined towards the north, and unique alleles were found in only three of the northern and three of southern sites. Genetic structuring did not indicate complete isolation among regions, but an increase of genetic isolation by geographic distance. Approximate Bayesian model choice suggested recent divergence during the postglacial period, but glacial refugia remain unidentified. The progressive reduction of suitable habitats is suggested to explain the genetic structure of the populations and we suggest that T. pinivora is a cold-tolerant relict species, with situation-dependent dispersal. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
14. Abundance-occupancy relationships in metapopulations: examples of rock pool Daphnia.
- Author
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Östman, Örjan
- Subjects
- *
DAPHNIA , *CLADOCERA , *METAPOPULATION (Ecology) , *HABITATS , *ECOLOGICAL heterogeneity , *ZOOGEOGRAPHY - Abstract
Intraspecific positive relationships between abundance and occupancy are observed for many species, suggesting that the same processes drive local and regional species dynamics. Two main groups of mechanisms explain this relationship: spatiotemporal variation in local population growth rates due to variation in habitat quality, or dispersal effects that increase occupancy of a species when locally abundant. Several studies show that spatiotemporal variation in population growth rates causes positive abundance-occupancy relationships, but few have shown dispersal effects. It is believed that such effects should be more evident for species whose dispersal is limited, e.g. metapopulations, but those studies are limited. This study investigates abundance-occupancy relationships in three Daphnia metapopulations in rock pools and the degree to which dispersal or habitat quality affect their local abundances and occurrence. Daphnia longispina and Daphnia magna showed positive abundance-occupancy relationships, but not Daphnia pulex. No single ecological factor could explain the abundance-occupancy relationships of any given species. Instead, dispersal processes and rock pool quality (mainly salinity and depth) seem to act together to shape the abundance-occupancy relationships. Such a conclusion is also supported by an immigration experiment in natural rock pools. This study suggests that although positive abundance-occupancy relationships may be commonly found for metapopulations, both dispersal processes and variation in habitat quality can be factors determining the abundance-occupancy relationship of metapopulations experiencing habitat heterogeneity. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
15. The evolutionary history of a mammal species with a highly fragmented range: the phylogeography of the European snow vole.
- Author
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Castiglia, R., Annesi, F., Kryštufek, B., Filippucci, M. G., and Amori, G.
- Subjects
- *
CHIONOMYS nivalis , *VOLES , *MITOCHONDRIAL DNA , *CYTOCHROME b - Abstract
The European snow vole Chionomys nivalis has a patchy distribution restricted to rocky habitats across southern Europe and the Near and Middle East. We carried out a phylogeographic study to provide a biogeographic scenario, based on molecular data, outlining the major processes that determined the current distribution of the species. The samples include 26 snow voles from 14 different populations across the entire species range from Spain to Anatolia and Israel. Nearly complete sequences (1037 bp) of the mitochondrial gene for cytochrome b were sequenced. Relationships among haplotypes were inferred with neighbour-joining, maximum likelihood, maximum parsimony analyses and minimum spanning network. An analysis of mismatch distribution was used to cast light on past demographic expansion. We found 22 different haplotypes that fall into six distinct lineages, all but one is supported by high bootstrap values with all methods. Four lineages are allopatric (Tatra Mts., Iberia, Balkans and Middle East) while divergent haplotypes from two lineages show sympatry in the Alps and the Apennines. The basal relationships of these lineages could not be established by any tree. The mean pairwise genetic distance between lineages ranges from 2.4 to 4.2%. The shape of the mismatch distribution indicated a past expansion event dating back to between 158 000 and 84 000 years ago. These data can be interpreted with the existence of southern glacial refugia (Iberia, Balkans, Middle East and Italy) and one additional northern glacial refugium. The lack of phylogenetic resolution among lineages and the shape of mismatch distribution are indicative of a simultaneous and rapid splitting due to a relatively fast initial expansion of populations. Moreover, the analysis supports the hypothesis of the European origin of C. nivalis and its subsequent eastward dispersion during the Middle Pleistocene. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
16. Phylogeography and population structure of Squalius lucumonis: A baseline for conservation of an Italian endangered freshwater fish.
- Author
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Rossi, Anna Rita, Petrosino, Gerardo, Crescenzo, Simone, Milana, Valentina, Talarico, Lorenzo, Martinoli, Marco, Rakaj, Arnold, Lorenzoni, Massimo, Carosi, Antonella, Ciuffardi, Luca, and Tancioni, Lorenzo
- Subjects
FRESHWATER fishes ,RARE fishes ,GENETIC variation ,WATERSHEDS ,POPULATION differentiation - Abstract
• Hydrographic fragmentation promotes genetic structure in brook chub. • Population differentiation is observed over short geographic distances. • Rivers' main course prevent brook chub populations admixing. • Different managements units are present within the species range. • Conservation actions should consider and protect the population diversity detected. The brook chub (Squalius lucumonis) is a freshwater fish, endemic of Central Italy, which is experiencing a rapid range decline so that it is presently listed as Critically Endangered in the Italian IUCN Red List. For effective conservation, information about the spatial pattern of genetic diversity is crucial. Therefore, we analysed the mitochondrial Control Region and nuclear (microsatellites) markers to investigate population genetic structure, demography and spatial diversity over the whole species distribution range. We revealed significant divergence among populations, even at the local spatial scale, according to the isolation by distance model. At the biogeographic spatial scale, genetic diversity was shaped by past hydrogeological and climatic events that isolated the principal drainage basins (Vara, Tiber and Arno) from each other. On the other hand, strong genetic differentiation within the Tiber drainage basin could be due to local factors that acted at single-stream scale, as recent barriers to fish dispersal and irregular seasonal flow rates typical of small Mediterranean streams. Our findings contribute to the basal data collection on S. lucumonis required by European Habitats Directive and necessary for planning protection actions. We recommend that the three river drainages and most of the sampling sites should be regarded as different Management Units (MUs) to preserve their genetic distinctiveness. A recovery plan for the brook chub should consider environmental intervention and creation of protected areas, as well as in situ/ex situ restocking activities with juveniles produced by breeders from the same MU, to preserve local (adaptive) diversity. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
17. Natal dispersal in great bustards: the effect of sex, local population size and spatial isolation.
- Author
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Martín, Carlos A., Alonso, Juan C., Alonso, Javier A., Palacín, Carlos, Magaña, Marina, and Martín, Beatriz
- Subjects
- *
BIOLOGICAL research , *HABITATS , *LAND capability for wildlife , *ANIMAL breeding , *ANIMAL dispersal , *BUSTARDS , *PHENOTYPIC plasticity , *GENOTYPE-environment interaction , *AIRPLANES - Abstract
1. We investigated the causes of natal dispersal in four Spanish areas where 35 breeding groups of the polygynous great bustard Otis tarda were monitored intensively. A total of 392 juveniles were radio-tracked between 1991 and 2006 by ground and via aeroplane to avoid potential biases derived from the non-detection of long-distance dispersers. 2. We explored 10 explanatory variables that were related to individual phenotypic features, habitat and conspecific traits in terms of group size and breeding performance, and spatial distribution of available breeding groups. Probability of group change and natal dispersal distances were investigated separately through multifactorial analyses. 3. Natal dispersal occurred in 47·8% of the birds and median natal dispersal distance of dispersers was 18·1 km (range 4·97–178·42 km). Sex largely determined the dispersal probability, with 75·6% of males being dispersers and 80·0% of females being philopatric, in contrast to the general pattern of female-biased dispersal found in most avian species. 4. Both the frequency of natal dispersal and dispersal distances were affected by the spatial distribution of breeding groups. More isolated groups showed a higher proportion of philopatric individuals, the effect being more evident in males than in females. This implies a reduction in gene flow in fragmented populations, as most genetic exchange is achieved through male dispersal. Additionally, dispersers hatched in more isolated groups tended to exhibit longer dispersal distances, which increases the associated energetic costs and mortality risks. 5. The dispersal decision was influenced by the number of conspecifics in the natal group. The individual probability of natal dispersal was related inversely to the size of the natal group, which supports the balanced dispersal model and the conspecific attraction hypothesis. 6. Overall, our results provide a good example of phenotypic plasticity and reinforce the current view that dispersal is an evolutionary complex trait conditioned by the interaction of individual, social and environmental causes that vary between individuals and populations. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
18. Phylogeographic insights into Artemisia crithmifolia (Asteraceae) reveal several areas of the Iberian Atlantic coast as refugia for genetic diversity
- Author
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Jaume Pellicer, Alfredo García-Fernández, Joan Vallès, Daniel Vitales, Teresa Garnatje, Ministerio de Economía, Industria y Competitividad (España), and Generalitat de Catalunya
- Subjects
0106 biological sciences ,geography ,Genetic diversity ,geography.geographical_feature_category ,Ecology ,Niche ,Fragmentation (computing) ,Last Glacial Maximum ,Conservation ,Plant Science ,Asteraceae ,Biology ,Fragmented distribution ,010603 evolutionary biology ,01 natural sciences ,Niche modelling ,Gene flow ,Phylogeography ,European Atlantic coasts ,Habitat ,Peninsula ,Coastal dune ecosystems ,Ecology, Evolution, Behavior and Systematics ,010606 plant biology & botany - Abstract
11 p., tablas, mapas -- Post-print del artículo publicado en Plant Systematics and Evolution. Versión revisada y corregida -- La versión online de este artículo contiene material suplementario, disponible en: http://doi.org/10.1007/s00606-017-1387-x, The study of fragmentation processes should be tackled using different approaches, in order to obtain solid and robust evidence that could help in identifying potential barriers and threats for species. In this study, we have evaluated the spatial fragmentation patterns in Artemisia crithmifolia (Asteraceae) along its current distribution along the Atlantic coastlines of Europe, from Portugal to the Netherlands and the UK. Niche modelling analyses considering current and past climatic conditions, combined with plastid markers, have been used to evaluate the disconnected distribution pattern of the species, genetic flow between populations and habitat suitability for present and past populations. Plastid markers showed very low variability, while suggesting that the westernmost populations from the Atlantic coast of the Iberian Peninsula are partially genetically isolated, due to the existence of a potential barrier for gene flow on the northern Spanish coast. However, niche models identify this area as a potential habitat for the species, even during the last glacial maximum (20,000 years ago). The combination of both techniques allows identification of potential refugia for the species, highlighting the most likely recolonisation routes and distribution patterns which resulted in the overall low levels of genetic diversity. Anthropogenic activities (urban sprawl, beach expansions, etc.) are most likely behind local extinctions, thus preventing the establishment and expansion of new populations., The study has been supported by Projects CGL2007-64839-C02-01/-02, CGL2010-22234-C02-01.02/BOS and CGL2013-49097-C2-2-P (Spanish Government) and 2014SGR514 (Catalan Government).
- Published
- 2017
19. Genetic diversity of fragmented populations ofPolygala reinii(Polygalaceae), a perennial herb endemic to Japan.
- Author
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Nakagawa, Masato
- Subjects
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POLYGALA , *POLYGALACEAE , *ISOENZYMES , *ENDEMIC plants - Abstract
Genetic variation at 10 allozyme loci was analyzed in 14 populations ofPolygala reinii(Polygalaceae), a perennial herb endemic to central Honshu, Japan, with a fragmented geographical distribution. The levels of genetic variation within species (P=80.0,A=3.10,HE=0.303) and within populations (P=42.1,A=1.61,HE=0.163) were considerably higher than the mean for other endemic plants or short-lived perennial herbs. Genetic differentiation among populations was also high (GST=0.404). The genetic distance phenogram tended to show a clustering of the populations reflecting the fragmentation of the species range. A principal component analysis revealed the same tendency, as well as three groupings of populations in the Tokai district, on the Kii Peninsula and in the northern Kinki district. A negative correlation was obtained between the levels of gene flow and geographical distance among the populations (r=-0.745,P<0.0001). These results indicated limited gene flow among populations inP. reinii, presumably due to the geographical isolation accompanying the fragmented distribution. On the other hand, the geographical differentiation between the Japan Sea and Pacific Ocean sides was found inP. reinii, suggesting the influence of postglacial migration on the establishment of the genetic structure of this species. [ABSTRACT FROM AUTHOR]
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- 2004
- Full Text
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20. Phylogeographic insights into Artemisia crithmifolia (Asteraceae) reveal several areas of the Iberian Atlantic coast as refugia for genetic diversity
- Author
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Ministerio de Economía, Industria y Competitividad (España), Generalitat de Catalunya, García-Fernández, Alfredo, Vitales, Daniel, Pellicer, Jaume, Garnatje, Teresa, Vallès, Joan, Ministerio de Economía, Industria y Competitividad (España), Generalitat de Catalunya, García-Fernández, Alfredo, Vitales, Daniel, Pellicer, Jaume, Garnatje, Teresa, and Vallès, Joan
- Abstract
The study of fragmentation processes should be tackled using different approaches, in order to obtain solid and robust evidence that could help in identifying potential barriers and threats for species. In this study, we have evaluated the spatial fragmentation patterns in Artemisia crithmifolia (Asteraceae) along its current distribution along the Atlantic coastlines of Europe, from Portugal to the Netherlands and the UK. Niche modelling analyses considering current and past climatic conditions, combined with plastid markers, have been used to evaluate the disconnected distribution pattern of the species, genetic flow between populations and habitat suitability for present and past populations. Plastid markers showed very low variability, while suggesting that the westernmost populations from the Atlantic coast of the Iberian Peninsula are partially genetically isolated, due to the existence of a potential barrier for gene flow on the northern Spanish coast. However, niche models identify this area as a potential habitat for the species, even during the last glacial maximum (20,000 years ago). The combination of both techniques allows identification of potential refugia for the species, highlighting the most likely recolonisation routes and distribution patterns which resulted in the overall low levels of genetic diversity. Anthropogenic activities (urban sprawl, beach expansions, etc.) are most likely behind local extinctions, thus preventing the establishment and expansion of new populations.
- Published
- 2017
21. The evolutionary history of a mammal species with a highly fragmented range: the phylogeography of the European snow vole
- Author
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Boris Kryštufek, Flavia Annesi, Giovanni Amori, Maria Grazia Filippucci, and Riccardo Castiglia
- Subjects
Sympatry ,Chionomys ,cytochrome b ,fragmented distribution ,glacial refugia ,mtDNA ,phylogeography ,Settore BIO/05 ,biology ,Range (biology) ,Ecology ,Species distribution ,Allopatric speciation ,biology.organism_classification ,mt dna ,chionomys ,cytochromeb ,European snow vole ,Phylogeography ,Refugium (population biology) ,Animal Science and Zoology ,Ecology, Evolution, Behavior and Systematics - Abstract
The European snow vole Chionomys nivalis has a patchy distribution restricted to rocky habitats across southern Europe and the Near and Middle East. We carried out a phylogeographic study to provide a biogeographic scenario, based on molecular data, outlining the major processes that determined the current distribution of the species. The samples include 26 snow voles from 14 different populations across the entire species range from Spain to Anatolia and Israel. Nearly complete sequences (1037 bp) of the mitochondrial gene for cytochrome b were sequenced. Relationships among haplotypes were inferred with neighbourjoining, maximum likelihood, maximum parsimony analyses and minimum spanning network. An analysis of mismatch distribution was used to cast light on past demographic expansion. We found 22 different haplotypes that fall into six distinct lineages, all but one is supported by high bootstrap values with all methods. Four lineages are allopatric (Tatra Mts., Iberia, Balkans and Middle East) while divergent haplotypes from two lineages show sympatry in the Alps and the Apennines. The basal relationships of these lineages could not be established by any tree. The mean pairwise genetic distance between lineages ranges from 2.4 to 4.2%. The shape of the mismatch distribution indicated a past expansion event dating back to between 158 000 and 84 000 years ago. These data can be interpreted with the existence of southern glacial refugia (Iberia, Balkans, Middle East and Italy) and one additional northern glacial refugium. The lack of phylogenetic resolution among lineages and the shape of mismatch distribution are indicative of a simultaneous and rapid splitting due to a relatively fast initial expansion of populations. Moreover, the analysis supports the hypothesis of the European origin of C. nivalis and its subsequent eastward dispersion during the Middle Pleistocene.
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- 2009
22. Natal dispersal in great bustards: the effect of sex, local population size and spatial isolation
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Marina Magaña, Beatriz Martín, Carlos Palacín, Javier Alonso, Juan C. Alonso, and Carlos A. Martín
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Male ,Survival ,Range (biology) ,Population Dynamics ,Conspecific attraction ,Biology ,Environment ,Spatial distribution ,Birds ,Sex-biased dispersal ,Sex Factors ,Animals ,Balanced dispersal ,Bustard ,Steppe-land bird ,Social Behavior ,Polygyny ,Ecology, Evolution, Behavior and Systematics ,Demography ,Population Density ,Phenotypic plasticity ,Otis tarda ,Ecology ,Philopatry ,biology.organism_classification ,Biological Evolution ,Fragmented distribution ,Phenotype ,Habitat ,Spain ,Biological dispersal ,Animal Science and Zoology ,Animal Migration ,Female ,Radio-tracking - Abstract
9 paginas, 3 figuras y 3 tables, 1 We investigated the causes of natal dispersal in four Spanish areas where 35 breeding groups of the polygynous great bustard Otis tarda were monitored intensively. A total of 392 juveniles were radio-tracked between 1991 and 2006 by ground and via aeroplane to avoid potential biases derived from the non-detection of long-distance dispersers. 2 We explored 10 explanatory variables that were related to individual phenotypic features, habitat and conspecific traits in terms of group size and breeding performance, and spatial distribution of available breeding groups. Probability of group change and natal dispersal distances were investigated separately through multifactorial analyses. 3 Natal dispersal occurred in 47·8% of the birds and median natal dispersal distance of dispersers was 18·1 km (range 4·97–178·42 km). Sex largely determined the dispersal probability, with 75·6% of males being dispersers and 80·0% of females being philopatric, in contrast to the general pattern of female-biased dispersal found in most avian species. 4 Both the frequency of natal dispersal and dispersal distances were affected by the spatial distribution of breeding groups. More isolated groups showed a higher proportion of philopatric individuals, the effect being more evident in males than in females. This implies a reduction in gene flow in fragmented populations, as most genetic exchange is achieved through male dispersal. Additionally, dispersers hatched in more isolated groups tended to exhibit longer dispersal distances, which increases the associated energetic costs and mortality risks. 5 The dispersal decision was influenced by the number of conspecifics in the natal group. The individual probability of natal dispersal was related inversely to the size of the natal group, which supports the balanced dispersal model and the conspecific attraction hypothesis. 6 Overall, our results provide a good example of phenotypic plasticity and reinforce the current view that dispersal is an evolutionary complex trait conditioned by the interaction of individual, social and environmental causes that vary between individuals and populations., The study was financed by the Dirección General de Investigación (projects PB91-0081, PB94-0068,PB97-1252 and BOS2002-01543), and the Instituto Nacional para la Conservación de la Naturaleza, with contributions from the Dirección General de Medio Natural of Madrid Community, the Junta de Andalucía, and the Junta de Castilla y León. The Consejerías de Medio Ambiente of the Madrid Community, Junta de Andalucía, Junta de Castilla y León and Navarra allowed us to capture and radio-tag the birds.
- Published
- 2008
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