scholarly journals Native <i>Dreissena</i> freshwater mussels in the Balkans: in and out of ancient lakes

2010 ◽  
Vol 7 (10) ◽  
pp. 3051-3065 ◽  
Author(s):  
T. Wilke ◽  
R. Schultheiß ◽  
C. Albrecht ◽  
N. Bornmann ◽  
S. Trajanovski ◽  
...  
Keyword(s):  
Native Species ◽  
Evolutionary History ◽  
Environmental Changes ◽  
Substantial Part ◽  
Ancient Lakes ◽  
Lake Ohrid ◽  
The Balkans ◽  
History Of ◽  
Limited Gene Flow ◽  
Time Frames

Abstract. The Balkans is a biogeographically highly diverse region and a worldwide hotspot of endemic freshwater diversity. A substantial part of this diversity is attributed to well recognized and potential ancient lakes in its southwestern part. However, despite considerable research efforts, faunal relationships among those lakes are not well understood. Therefore, genetic information from native representatives of the mussel genus Dreissena is here used to test the biogeographical zonation of the southwestern Balkans, to relate demographic changes to environmental changes, to assess the degree of eco-insularity, to reconstruct their evolutionary history, and to explore the potential of native taxa for becoming invasive. Phylogeographical and population genetic analyses indicate that most studied populations belong to two native species: D. presbensis (including the distinct genetic subgroup from Lake Ohrid, "D. stankovici") and D. blanci. In addition, the first confirmed record of invasive D. polymorpha in the southwestern Balkan is presented. The distribution of native Dreissena spp. generally coincides with the biogeographical zonations previously suggested based on fish data. However, there is disagreement on the assignment of the ancient lakes in the area to respective biogeographical regions. The data for Lake Ohrid are not conclusive. A closer biogeographical connection to lakes of the Vardar region and possibly the northern Ionian region is, however, suggested for Lake Prespa. The reconstruction of the evolutionary history of Dreissena spp. suggests that populations underwent demographic and spatial expansions in the recent past. Expansions started around 320 000–300 000 years ago in "D. stankovici", 160 000–140 000 years ago in D. blanci, and 110 000–70 000 years ago in D. presbensis. These time frames are discussed within the context of available paleogeological data for lakes Ohrid and Prespa. It is suggested that regional environmental changes may have had pronounced effects on the population histories of native Dreissena spp., though the high buffer capacity of Lake Ohrid may have lessened these effects in "D. stankovici". In addition, local events influencing individual lakes had very likely considerable effects on the demographic histories of Dreissena spp. as well. The observed patterns of immigration and emigration in and out of ancient lakes may suggest that limited gene flow enabled the survival of few isolated subpopulations and that later on eco-insularity (selective advantages of locally adopted groups) may have prevented excessive hybridization and sympatry of closely related taxa. As for the potential invasiveness of native Dreissena spp., the inferred spatial expansions are not human-mediated and all taxa still appear to be restricted to their native ranges. A concern, however, is that today D. presbensis and D. blanci also occur in artificial water bodies, and that invasive D. polymorpha has reached the area.

scholarly journals Native <i>Dreissena</i> freshwater mussels in the Balkans: in and out of ancient lakes

2010 ◽  
Vol 7 (3) ◽  
pp. 4425-4461 ◽  
Author(s):  
T. Wilke ◽  
R. Schultheiß ◽  
C. Albrecht ◽  
N. Bornmann ◽  
S. Trajanovski ◽  
...  
Keyword(s):  
Native Species ◽  
Environmental Changes ◽  
Substantial Part ◽  
Ancient Lakes ◽  
Lake Ohrid ◽  
The Balkans ◽  
Limited Gene Flow ◽  
Genetic Subgroup ◽  
Biogeographical Regions ◽  
Time Frames

Abstract. The Balkans is a biogeographically highly diverse region and a worldwide hotspot of endemic freshwater diversity. A substantial part of this diversity is attributed to well recognized and potential ancient lakes in its southwestern part. Despite considerable research efforts, faunal relationships among those lakes are, however, not well understood. Therefore, genetic information from native representatives of the mussel genus Dreissena is used here to test the biogeographical zonation of the Southwestern Balkans, to relate demographic changes to environmental changes, to assess the degree of eco-insularity, to reconstruct their evolutionary history, and to explore the potential of native taxa for becoming invasive. Phylogeographical and population genetic analyses indicate that most populations studied belong to two native species: D. presbensis (incl. the distinct genetic subgroup from Lake Ohrid, D. ''stankovici'') and D. blanci. In addition, the first confirmed record of invasive D. polymorpha in the Southwestern Balkan is presented. The distribution of native Dreissena spp. is largely in concordance with the biogeographical zonations previously proposed based on fish data. Disagreement, however, consists regarding the assignment of the ancient lakes in the area to biogeographical regions. The data for Lake Ohrid are not conclusive. For Lake Prespa, however, a closer biogeographical connection to lakes of the Vardar region and possibly the Northern Ionian region is suggested. While reconstructing the evolutionary histories of Dreissena spp., signs of major demographic and spatial expansions were found. They started some 320 000–300 000 years ago in D. ''stankovici'', some 160 000–140 000 years ago in D. blanci, and some 110 000–70 000 years ago in D. presbensis. These time frames are discussed within the context of available paleogeological data for lakes Ohrid and Prespa. It is suggested that regional environmental changes may have had pronounced effects on the population histories of native Dreissena spp., though the high buffer capacity of Lake Ohrid may have mitigated these effects in D. ''stankovici''. In addition, local events acting upon individual lakes very likely had considerable effects on the demographic histories of Dreissena spp. as well. The observed patterns of immigration and emigration in and out of ancient lakes may suggest that limited gene flow supported the survival of small isolated subpopulations, while eco-insularity may have prevented excessive hybridization and sympatry of closely related taxa. As for the potential invasiveness of native Dreissena spp., the significant spatial expansions inferred are not human-mediated and all taxa still appear to be restricted to their native ranges. Of concern, however, is that D. presbensis and D. blanci today also occur in artificial water bodies, and that invasive D. polymorpha has reached the area.

scholarly journals Phylogeographic analysis and species distribution modelling of the wood frog Batrachyla leptopus (Batrachylidae) reveal interglacial diversification in south western Patagonia

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9980
Author(s):  
José J. Nuñez ◽  
Elkin Y. Suárez-Villota ◽  
Camila A. Quercia ◽  
Angel P. Olivares ◽  
Jack W. Sites Jr
Keyword(s):  
Population Structure ◽  
Species Distribution ◽  
Evolutionary History ◽  
Environmental Changes ◽  
Glacial Refugia ◽  
Species Distribution Modelling ◽  
Wood Frog ◽  
Type I ◽  
Distribution Modelling ◽  
History Of

Background The evolutionary history of southern South American organisms has been strongly influenced by Pleistocene climate oscillations. Amphibians are good models to evaluate hypotheses about the influence of these climate cycles on population structure and diversification of the biota, because they are sensitive to environmental changes and have restricted dispersal capabilities. We test hypotheses regarding putative forest refugia and expansion events associated with past climatic changes in the wood frog Batrachyla leptopus distributed along ∼1,000 km of length including glaciated and non-glaciated areas in southwestern Patagonia. Methods Using three mitochondrial regions (D-loop, cyt b, and coI) and two nuclear loci (pomc and crybA1), we conducted multilocus phylogeographic analyses and species distribution modelling to gain insights of the evolutionary history of this species. Intraspecific genealogy was explored with maximum likelihood, Bayesian, and phylogenetic network approaches. Diversification time was assessed using molecular clock models in a Bayesian framework, and demographic scenarios were evaluated using approximate Bayesian computation (ABC) and extended Bayesian skyline plot (EBSP). Species distribution models (SDM) were reconstructed using climatic and geographic data. Results Population structure and genealogical analyses support the existence of four lineages distributed north to south, with moderate to high phylogenetic support (Bootstrap > 70%; BPP > 0.92). The diversification time of B. leptopus’ populations began at ∼0.107 mya. The divergence between A and B lineages would have occurred by the late Pleistocene, approximately 0.068 mya, and divergence between C and D lineages was approximately 0.065 mya. The ABC simulations indicate that lineages coalesced at two different time periods, suggesting the presence of at least two glacial refugia and a postglacial colonization route that may have generated two southern lineages (p = 0.93, type I error: <0.094, type II error: 0.134). EBSP, mismatch distribution and neutrality indexes suggest sudden population expansion at ∼0.02 mya for all lineages. SDM infers fragmented distributions of B. leptopus associated with Pleistocene glaciations. Although the present populations of B. leptopus are found in zones affected by the last glacial maximum (∼0.023 mya), our analyses recover an older history of interglacial diversification (0.107–0.019 mya). In addition, we hypothesize two glacial refugia and three interglacial colonization routes, one of which gave rise to two expanding lineages in the south.

scholarly journals Neogene paleogeography provides context for understanding the origin and spatial distribution of cryptic diversity in a widespread Balkan freshwater amphipod

2017 ◽  
Author(s):  
Michał Grabowski ◽  
Tomasz Mamos ◽  
Karolina Bącela-Spychalska ◽  
Tomasz Rewicz ◽  
Remi A Wattier
Keyword(s):  
Evolutionary History ◽  
28S Rdna ◽  
Cryptic Diversity ◽  
The Balkans ◽  
Operational Taxonomic Units ◽  
Freshwater Biota ◽  
History Of ◽  
Riverine Habitats ◽  
Coi Sequences ◽  
High Level

Background. The Balkans are a major biodiversity and endemism hotspot, worldwide. Among the freshwater biota, amphipods are known for their high cryptic diversity. However, little is known about the temporal and paleogeographic aspects of their evolutionary history. We used paleogeography as a framework for understanding the onset of diversification in Gammarus roeselii: 1) we hypothesised that, given the high number of isolated waterbodies in the Balkans, the species is characterised by high level of cryptic diversity, even on a local scale; 2) the long geological history of the region might promote pre-Pleistocene divergence between lineages; 3) given that G. roeselii thrives both in lakes and rivers, its evolutionary history could be linked to the Balkan Neogene paleolake system; 4) we inspected whether the Pleistocene decline of hydrological networks could have any impact on the diversification of G. roeselii. Material and Methods. DNA was extracted from 136 individuals collected from 26 sites all over Balkans. All individuals were amplified for ca. 650 bp long fragment of the mtDNA cytochrome oxidase subunit I (COI). After defining molecular operational taxonomic units (MOTU) based on COI, 50 individuals were amplified for ca. 900 bp long fragment of the nuclear 28S rDNA. Molecular diversity, divergence, differentiation and historical demography based on COI sequences were estimated for each MOTU. The relative frequency, geographic distribution and molecular divergence between COI haplotypes were presented as a median-joining network. COI was used also to reconstruct time-calibrated phylogeny with Bayesian inference. Probabilities of ancestors' occurrence in riverine or lacustrine habitats, as well their possible geographic locations, were estimated with the Bayesian method. A Neighbour Joining tree was constructed to illustrate the phylogenetic relationships between 28S rDNA haplotypes. Results. We revealed that G. roeselii includes at least 13 cryptic species or molecular operational taxonomic units (MOTUs), mostly of Miocene origin. A substantial Pleistocene diversification within-MOTUs was observed in several cases. We evidenced secondary contacts between very divergent MOTUs and introgression of nDNA. The Miocene ancestors could live in either lacustrine or riverine habitats yet their presumed geographic localisations overlapped with those of the Neogene lakes. Several extant riverine populations had Pleistocene lacustrine ancestors. Discussion. Neogene divergence of lineages resulting in substantial cryptic diversity may be a common phenomenon in extant freshwater benthic crustaceans occupying areas that were not glaciated during the Pleistocene. Evolution of G. roeselii could be associated with gradual deterioration of the paleolakes. The within-MOTU diversification might be driven by fragmentation of river systems during the Pleistocene. Extant ancient lakes could serve as local microrefugia during that time.

scholarly journals The evolutionary history of dogs in the Americas

Science ◽  
2018 ◽  
Vol 361 (6397) ◽  
pp. 81-85 ◽  
Author(s):  
Máire Ní Leathlobhair ◽  
Angela R. Perri ◽  
Evan K. Irving-Pease ◽  
Kelsey E. Witt ◽  
Anna Linderholm ◽  
...  
Keyword(s):  
Native American ◽  
North American ◽  
Evolutionary History ◽  
Monophyletic Lineage ◽  
History Of ◽  
Nuclear Genomes ◽  
Time Frames

Dogs were present in the Americas before the arrival of European colonists, but the origin and fate of these precontact dogs are largely unknown. We sequenced 71 mitochondrial and 7 nuclear genomes from ancient North American and Siberian dogs from time frames spanning ~9000 years. Our analysis indicates that American dogs were not derived from North American wolves. Instead, American dogs form a monophyletic lineage that likely originated in Siberia and dispersed into the Americas alongside people. After the arrival of Europeans, native American dogs almost completely disappeared, leaving a minimal genetic legacy in modern dog populations. The closest detectable extant lineage to precontact American dogs is the canine transmissible venereal tumor, a contagious cancer clone derived from an individual dog that lived up to 8000 years ago.

scholarly journals Evolution of the extracytoplasmic function σ factor protein family

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Daniela Pinto ◽  
Rute R da Fonseca
Keyword(s):  
Soil Bacteria ◽  
Scientific Community ◽  
Evolutionary History ◽  
Environmental Changes ◽  
Σ Factor ◽  
History Of ◽  
Promoter Specificity ◽  
Partner Proteins ◽  
Relevant Gene ◽  
Recent Duplication

Abstract Understanding transcription has been a central goal of the scientific community for decades. However, much is still unknown, especially concerning how it is regulated. In bacteria, a single DNA-directed RNA-polymerase performs the whole of transcription. It contains multiple subunits, among which the σ factor that confers promoter specificity. Besides the housekeeping σ factor, bacteria encode several alternative σ factors. The most abundant and diverse family of alternative σ factors, the extracytoplasmic function (ECF) family, regulates transcription of genes associated with stressful scenarios, making them key elements of adaptation to specific environmental changes. Despite this, the evolutionary history of ECF σ factors has never been investigated. Here, we report on our analysis of thousands of members of this family. We show that single events are in the origin of alternative modes of regulation of ECF σ factor activity that require partner proteins, but that multiple events resulted in acquisition of regulatory extensions. Moreover, in Bacteroidetes there is a recent duplication of an ecologically relevant gene cluster that includes an ECF σ factor, whereas in Planctomycetes duplication generates distinct C-terminal extensions after fortuitous insertion of the duplicated σ factor. At last, we also demonstrate horizontal transfer of ECF σ factors between soil bacteria.

scholarly journals Neogene paleogeography provides context for understanding the origin and spatial distribution of cryptic diversity in a widespread Balkan freshwater amphipod

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3016 ◽  
Author(s):  
Michał Grabowski ◽  
Tomasz Mamos ◽  
Karolina Bącela-Spychalska ◽  
Tomasz Rewicz ◽  
Remi A. Wattier
Keyword(s):  
Evolutionary History ◽  
28S Rdna ◽  
Cryptic Diversity ◽  
The Balkans ◽  
Operational Taxonomic Units ◽  
Freshwater Biota ◽  
History Of ◽  
Riverine Habitats ◽  
Coi Sequences ◽  
High Level

BackgroundThe Balkans are a major biodiversity and endemism hotspot, worldwide. Among the freshwater biota, amphipods are known for their high cryptic diversity. However, little is known about the temporal and paleogeographic aspects of their evolutionary history. We used paleogeography as a framework for understanding the onset of diversification inGammarus roeselii: (1) we hypothesised that, given the high number of isolated waterbodies in the Balkans, the species is characterised by high level of cryptic diversity, even on a local scale; (2) the long geological history of the region might promote pre-Pleistocene divergence between lineages; (3) given thatG. roeseliithrives both in lakes and rivers, its evolutionary history could be linked to the Balkan Neogene paleolake system; (4) we inspected whether the Pleistocene decline of hydrological networks could have any impact on the diversification ofG. roeselii.Material and MethodsDNA was extracted from 177 individuals collected from 26 sites all over Balkans. All individuals were amplified for ca. 650 bp long fragment of the mtDNA cytochrome oxidase subunit I (COI). After defining molecular operational taxonomic units (MOTU) based on COI, 50 individuals were amplified for ca. 900 bp long fragment of the nuclear 28S rDNA. Molecular diversity, divergence, differentiation and historical demography based on COI sequences were estimated for each MOTU. The relative frequency, geographic distribution and molecular divergence between COI haplotypes were presented as a median-joining network. COI was used also to reconstruct time-calibrated phylogeny with Bayesian inference. Probabilities of ancestors’ occurrence in riverine or lacustrine habitats, as well their possible geographic locations, were estimated with the Bayesian method. A Neighbour Joining tree was constructed to illustrate the phylogenetic relationships between 28S rDNA haplotypes.ResultsWe revealed thatG. roeseliiincludes at least 13 cryptic species or molecular operational taxonomic units (MOTUs), mostly of Miocene origin. A substantial Pleistocene diversification within-MOTUs was observed in several cases. We evidenced secondary contacts between very divergent MOTUs and introgression of nDNA. The Miocene ancestors could live in either lacustrine or riverine habitats yet their presumed geographic localisations overlapped with those of the Neogene lakes. Several extant riverine populations had Pleistocene lacustrine ancestors.DiscussionNeogene divergence of lineages resulting in substantial cryptic diversity may be a common phenomenon in extant freshwater benthic crustaceans occupying areas that were not glaciated during the Pleistocene. Evolution ofG. roeseliicould be associated with gradual deterioration of the paleolakes. The within-MOTU diversification might be driven by fragmentation of river systems during the Pleistocene. Extant ancient lakes could serve as local microrefugia during that time.

scholarly journals Environmental changes on the Balkans recorded in the sediments from lakes Prespa and Ohrid

2010 ◽  
Vol 7 (3) ◽  
pp. 3365-3392 ◽  
Author(s):  
B. Wagner ◽  
H. Vogel ◽  
G. Zanchetta ◽  
R. Sulpizio
Keyword(s):  
Organic Matter ◽  
Environmental History ◽  
Environmental Changes ◽  
Lake Ohrid ◽  
Sediment Record ◽  
The Balkans ◽  
Lake Prespa ◽  
Tephra Layers ◽  
High Carbonate ◽  
Comparison Of The Results

Abstract. Lakes Prespa and Ohrid on the Balkans are considered to be amongst the oldest lakes in Europe. Both lakes are hydraulically connected via karst aquifers. From Lake Ohrid, several up to ca. 15 m long sediment records were studied during the past years. In this study, a first long sediment record from Lake Prespa was studied in order to shed more light on the influence of Lake Prespa on Lake Ohrid and the environmental history of the region. Radiocarbon dating and the occurrence of 3 dated tephra layers provide a good age control and indicate that the 10.5 m long sediment record reaches back to 48 ka. The comparison of the results from this study with those from former studies of the Lake Ohrid cores indicates that Lake Prespa is more susceptible to environmental changes due to its lower volume and water depth. Glacial sedimentation is characterized by low organic matter contents and absence of carbonates in the sediments, which indicate oligotrophic conditions in both lakes. Holocene sedimentation is characterized by particularly high carbonate contents in Lake Ohrid and by particularly high organic matter contents in Lake Prespa, which indicate a shift towards more mesotrophic conditions in the latter. Long-term environmental changes and short-term events, such as the Heinrich events during the Pleistocene or the 8.2 cooling event during the Holocene, are well recorded in both lakes, but partly expressed in different proxies.

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