Search Results (55)

The lithological record of past climates and climate changes reveals significant potential in enhancing education and understanding of global climate changes and their impacts on contemporary societies. A relatively young geological record of Pleistocene cooling and glaciations serves as one of the most useful geo-educational tools. The present study encompasses a comprehensive review of ongoing efforts to assess and communicate the glacial geoheritage of the Pleistocene, with a detailed case study of Poland. A literature review is conducted to evaluate the extent of scientific work on inventorying and communicating the geodiversity of Pleistocene glacial and periglacial environments globally. The study demonstrates a steady increase in the number of scientific contributions focused on the evaluation and promotion of Pleistocene geoheritage, with a notable transition from the description of geosites to the establishment of geoconservation practices and educational strategies. The relative complexity of the palaeoclimatic record and the presence of glacial geodiversity features across extensive areas indicate that effective scientific communication of climate changes requires careful selection of a limited number of geodiversity elements and sediment types. In this context, the use of glacial erratic boulders and rock gardens for promotion of Pleistocene glacial geoheritage is advocated, and the significance of educational initiatives for local communities and the preservation of geocultural heritage is outlined in detail. Full article

Previous phylogeographic study of the root vole (Alexandromys oeconomus) revealed four mitochondrial cytochrome b lineages—North and Central European, North (=Central) Asian and Beringian. Three of them were studied in detail, while the North Asian lineage, which occupies the most extensive territory and is considered to be the place of origin for the species, was understudied. In the framework of the current study, we obtained 95 new sequences (34 localities) from the wide territory of Northern Asia and in total, examined 940 specimens from 181 localities throughout the species’ distribution range. The North Asian lineage was found to be more diverse than the Beringian and the European lineages. Southern Siberia and especially the Altai–Sayan region displayed the highest haplotype and nucleotide diversity, suggesting the region’s role as a genetic diversity hotspot. We suppose that the expansion of the North Asian lineage started from Western Transbaikalia. Its representatives colonised the territory from the Urals to the northern shore of the Okhotsk Sea, and then spread in the opposite direction, to Southern Siberia. As a result, a mixture of haplogroups is observed in the Altai–Sayan region. According to the BEAST analysis calibrated with the first A. oeconomus records, the MRCA of North Asian and Beringian lineages is dated back to ~0.82 Mya, and the first divergence within the North Asian lineage may have occurred ~0.6 Mya. When compared with colonisation times of other representatives of the Arvicolinae subfamily, our dating seems to be overestimated. In this regard, molecular data for dated fossil remains of the root vole are essential for subsequent studies. Full article

Coastal shellfish farming areas in northern China seas face frequent starfish outbreaks, particularly from Asterias amurensis and Patiria pectinifera, leading to significant economic losses. Genomic data are key to understanding the population dynamics and adaptive traits and developing effective control measures for these species. Here, we characterized and compared the genomic information of these two starfish using a whole-genome survey approach. The genome size of A. amurensis is ~477 Mb with 1.52% heterozygosity, 53.60% repetitive sequences, and 39.94% GC content, while P. pectinifera has a ~529 Mb genome, 2.90% heterozygosity, 56.02% repetitive sequences, and 40.63% GC content. Scaffold N50 values were 1823 bp for A. amurensis and 1328 bp for P. pectinifera. We identified 161,786 microsatellite motifs in A. amurensis and 316,245 in P. pectinifera, with mononucleotide repeats being the most common. A total of 171 single-copy homologous genes were found in A. amurensis, with 94 in P. pectinifera. For both species, KEGG annotation showed functional similarities in glycan biosynthesis, translation, metabolism, catabolism, and transport. The Pairwise Sequentially Markovian Coalescent (PSMC) analysis unveiled a bottleneck effect during the Pleistocene glaciation. Additionally, phylogenetic analysis of mitochondrial genomes indicates that P. pectinifera and Patiria miniata of the same genus belong to the same branch in the evolutionary tree as sister groups with the closest genetic relationship, while A. amurensis is most closely related to Astropecten polyacanthus within the class Asteroidea. These findings provide valuable genomic insights for both species. Full article

Anemone altaica Fisch. ex C. A. Mey., a component of the tertiary boreo-nemoral vegetation complex, exhibits a disjunct distribution from European Russia to Central China. The Khamar-Daban Ridge, extending along Lake Baikal’s southern coast, has served as a refugium preserving mesophilic forest remnants in South Siberia since the Pleistocene. This study aimed to elucidate the phylogenetic relationships and historical biogeography of A. altaica within the Khamar-Daban refugium using plastid DNA markers (trnL + trnL-trnF). Phylogenetic and mismatch distribution analysis revealed polyphyly (more specifically diphyly) among A. altaica lineages, suggesting past hybridization events with related species followed by backcrossing. Estimation of isolation by distance effect, spatial autocorrelation analysis, PCoA, and AMOVA indicated a clear spatial genetic structure for A. altaica on the Khamar-Daban Ridge. The most reliable geographical model suggests that during periods of Pleistocene cooling, A. altaica persisted in at least six microrefugia within the ridge. Populations associated with these microrefugia formed western, central, and eastern genetic supergroups with limited gene flow among them. Gene flow likely occurred more easily during glaciations or early interglacials when the subalpine zone shifted closer to Lake Baikal due to the depression of the snow boundary, allowing adjacent populations to intermingle along the glacial edges and terminal moraines in mountain forest belt. Full article

Although the Late Pleistocene glaciation history of the Fraser Lowland (BC, Canada) is relatively well studied, little is known about ice-flow directions during the last glaciation (Fraser glaciation). Lidar imagery from the western Fraser Lowland was used to identify and interpret previously unrecognized glacial landforms in a heavily urbanized and vegetated area. This indicates patterns of ice flow during the latest stage of the Fraser glaciation (Vashon stade) of the Cordilleran Ice Sheet. The imagery provides a picture of dominant SSE flow from the Strait of Georgia in the western part of the study area, and SSW flow from the southern Coast Mountain valleys in the eastern part, resulting in an overall southward flow, as documented in the uplands in the southern part of our study area. No evidence for a substantially different ice flow could be identified. Three new radiocarbon ages from the Sechelt area ca. 40 km northwest of the Fraser Lowland indicate a proximal ice margin in the Strait of Georgia already ca. 30 cal ka BP, well before the Coquitlam ice advance in the Fraser Lowland. These ages contribute to the unsolved discussion if this ice margin advanced onto the Fraser Lowland, yet further studies are needed. Full article

The Eastern Baltic area stands out as a unique location due to the finds of Europe’s youngest dated mammoth remains (12.6–11.2 ka cal BP). Our study explores the drastic climate and landcover changes during the extinction of these gigantic herbivores at the Pleistocene/Holocene boundary. We used macrofossil analysis to determine the major contemporary terrestrial plant genera present in the area and used corresponding pollen taxa for REVEALS model-based landcover reconstructions. Our results indicate that these last mammoths utilised the open landcover of the Eastern Baltic, which developed as the continental ice sheet retreated during the termination of the last glaciation. Due to climate warming during the initial stages of the Holocene interglacial, the Eastern Baltic became speedily populated by birch and pine forests. The abrupt disappearance of typical forb-dominated tundra indicators, such as Dryas octopetala, and the fast increase in tree birch marked a shift from an open, tundra-like landscape to a forested one, making the environment inhospitable for mammoths even in northernmost Estonia by the beginning of the Holocene. A comparison between the isotopic values of nitrogen (δ¹⁵N) and carbon (δ¹³C) obtained from mammoths’ molars from 14.3 and 11.3 to 43.5 and 39.1 ka cal BP showed that mammoths experienced a decline in the nutritional value of their diet, resulting in their demise in the Eastern Baltic. Full article

The genus Discogobio is distributed in the eastern three rivers on the Yunnan–Guizhou Plateau and its adjacent regions, located to the southeast of the Qinghai–Tibet Plateau. Its origin and evolution are likely influenced by the uplift of the Qinghai-Tibet Plateau. However, the historical impact of geological events on the divergence and distribution of this fish group has not been fully elucidated. In this study, we successfully assembled a chromosome-level genome for Discogobio brachyphysallidos, which is approximately 1.21 Gb in length with a contig N50 of 8.63 Mb. The completeness of the genome assembly was assessed with a BUSCO score of 94.78%. A total of 30,597 protein-coding genes were predicted, with 93.92% functionally annotated. Phylogenetic analysis indicated that D. brachyphysallidos was closely related to Labeo rohita, and the divergence of the subfamily Labeoninae coincided with the significant uplift events of the Qinghai–Tibet Plateau. Additionally, we analyzed 75 samples of D. brachyphysallidos and D. yunnanensis from five populations, yielding 1.82 Tb of clean data and identifying 891,303,336 high-quality SNP sites. Population structure analyses indicated that the populations were clustered into five distinct groups, demonstrating significant genetic differentiation among them and the presence of cryptic species within this genus. Analyses of linkage disequilibrium decay and selective sweep indicated that the Pearl River population exhibited relatively higher genetic diversity compared with the populations from other drainages, and none of the populations showed evidence of expansion. Notably, the two population declines coincided with the early Pleistocene and Quaternary glaciation. It can be assumed that the geological movements of the Qinghai–Tibet Plateau and the Quaternary glaciation contributed to the decline in Discogobio populations and shaped their current size. The population genomics results showed that the present distribution pattern of Discogobio was the outcome of a series of geological events following the uplift of the Qinghai–Tibet Plateau. This study reconstructed the geological evolutionary history of the region from the perspective of species evolution. Furthermore, our study presents the first genome-wide analysis of the genetic divergence of Discogobio. Full article

Situated throughout the southeastern United States within the Laurentian craton are occurrences of various aged deposits (Late Proterozoic to Early Paleogene) that contain volcanics spanning from lamprophyres to carbonatites and basalts to rhyolites. Several are intrusive, while others have been reworked detritally, deposited as river gravels out onto the Gulf Coastal Plain. The earliest occurrence of igneous gravel clasts in the coastal plain of the lower Mississippi Valley lie along the Mississippi River’s eastern valley wall in the ancestral Mississippi River’s pre-loess terrace deposits (PLTDs). The coarse clastics of the PLTDs are dominantly chert gravels derived from Paleozoic carbonate bedrock, but also include clasts of Precambrian Sioux Quartzite, glacially faceted and striated stones, and ice-rafted boulders, which indicate a direct relationship between the PLTDs and glacial outwash during the cyclic glaciation of the Pleistocene Epoch. The PLTDs also contain the oldest known examples of igneous gravels exposed at the surface in Mississippi. An understanding of their igneous bedrock provenance and the timing of their contribution to the sedimentary record of the lower Mississippi River Valley sheds a valuable light onto the geologic history and evolution of the ancestral Mississippi River during the Pleistocene Epoch. The use of fusion inductively coupled plasma mass-spectroscopy (ICP-MS) in the identification of the igneous suites of one of the pre-loess terraces, well-delineated by geologic mapping, adds important geochemical source data from the gravel constituents for the further interpretation and correlation of the individual PLTD allounits. Gravel constituent geochemistry also offers a better understanding of the evolution of the ancestral Mississippi River watershed and the contributions of bedrock sources during Pleistocene glaciation. This petrological study suggests that the igneous gravels sampled from within the Rawhide PLTD allounit originated from the St. Francois Mountains (SFMs) in southwestern Missouri, with the implications that the SFM igneous terrain was in the direct path of the Independence “Kansan” glaciation. This could indicate a glacial extent further southwest than previously documented. Full article

Since prehistoric times, indigenous residents of southwest British Columbia, Canada, collected water-worn nephrite specimens from the gravel bars along the Fraser River, using the stone for the manufacture of tools that were widely traded with other tribes. Allochthonous nephrite occurs in another geologic setting. Late Pleistocene continental glaciers transported nephrite and many other rock types from western Canada to northwest Washington State, producing extensive sediment deposits that border the Salish Sea coast in Whatcom and Island Counties, Washington. This material was little utilized by indigenous residents, but “black jade” specimens are prized by modern collectors. The depositional history and mineralogy of this material has received little attention. X-ray diffraction and SEM/EDS analyses indicate that the Salish Sea “black jade” is a form of impure nephrite that probably originated from metamorphism of a mafic igneous parent material (metabasite). The texture consists of prismatic amphibole crystals (ferro-actinolite) set in a matrix rich in plagioclase feldspar. Pyrite inclusions are locally present. A second material, sometimes erroneously labelled “muttonfat jade” by amateur collectors, consists of an intermixture of quartz and sillimanite. Full article

Walleye, Sander vitreus, has several distinct genetic lineages throughout North America as a consequence of Pleistocene glaciation. Stocking walleye across genetic boundaries in the mid-20th century has led to the introduction of non-native strains that persist to this day. In West Virginia, the identification of the native Eastern Highlands strain led the West Virginia Division of Natural Resources (WVDNR) to employ broodstock screening to assist in the conservation of the native strain. To develop a baseline native ancestry prevalence in walleye populations throughout the state, 1532 broodstock were sampled across 17 sampling locations over a 6-year period. To evaluate the effectiveness of the current broodstock two-SNP qPCR assay protocol and identify whether more SNPs need to be implemented, 284 walleye were sequenced and ancestry-genotyped across 42 fixed SNPs between the two strains. When comparing the current protocol to the older microsatellite protocol, advancement in the ability to identify native-strain individuals was observed. Genotyping previously assigned walleye broodstock across multiple fixed SNPs revealed that the current ancestry assignment protocol, on average, assigned individuals that display 96% Eastern Highlands native ancestry to the native strain and accurately identified >93% of all pure Eastern Highlands walleye. Throughout the state of West Virginia, the New and Kanawha River systems contained a high prevalence of native ancestry, with the Ohio River and sampled impoundments displaying varying levels of ancestry. SNPs with >98% prevalence in individuals assigned to the Eastern Highlands strain were identified during the course of the study and can be implemented in future screening protocols. Our results highlight the utility of genomic approaches as tools to assist fisheries management goals and their capability to accurately identify native ancestry to assist in conservation efforts. Full article

The assassin bug Sycanus bifidus has a wide distribution across southern China. This study explored its distribution and evolution by analyzing mitochondrial and nuclear ribosomal RNA genes, revealing how Pleistocene climate and geological changes shaped its phylogeography. We identified two main clades, A and B, that diverged in the Middle Pleistocene. Hainan Island’s populations form a unique group within Clade A, suggesting that the Qiongzhou Strait served as a dispersal corridor during glaciation. Rising sea levels likely separated the Hainan population afterward. Ecological niche modeling showed that both populations have been viable since the last interglacial period, with demographic analyses indicating possible expansions during the Middle and Late Pleistocene, driven by favorable climates. This study highlights the significant effects of Pleistocene sea-level and climatic changes on the distribution and evolution of S. bifidus in China. Full article

The Italian fauna includes about 170 species/subspecies of dung beetles, being one of the richest in Europe. We used data on dung beetle distribution in the Italian regions to investigate some macroecological patterns. Specifically, we tested if species richness decreased southward (peninsula effect) or northward (latitudinal gradient). We also considered the effects of area (i.e., the species–area relationship), topographic complexity, and climate in explaining dung beetle richness. Finally, we used multivariate techniques to identify biotic relationships between regions. We found no support for the peninsula effect, whereas scarabaeines followed a latitudinal gradient, thus supporting a possible role of southern areas as Pleistocene refuges for this group of mainly thermophilic beetles. By contrast, aphodiines were more associated with cold and humid climates and do not show a distinct latitudinal pattern. In general, species richness was influenced by area, with the Sardinian fauna being however strongly impoverished because of its isolation. Faunal patterns for mainland regions reflect the influence of current ecological settings and historical factors (Pleistocene glaciations) in determining species distributions. Full article

The joint impacts of historical geological events and Quaternary climatic oscillations in Northwest China on species evolution have been examined extensively in plant under a phylogeographic perspective. However, animal phylogeographic analyses in this region are still limited. The Alashan pit viper, Gloydius cognatus, occurs primarily in arid Northwest China and adjacent areas. Based on variation at two mtDNA genes (ND4 and Cytb) in 27 individuals representing 24 populations, the spatial genetic structure and demographic history of G. cognatus were examined across its geographic range. Phylogenetic analyses revealed two well-supported allopatric clades (each with two distinct subclades/lineages), distributed across the southern (Qaidam Basin, Lanzhou Basin, and Zoige Basin [S1]; Loess Plateau [S2]) and northern (Ily Basin [N1]; Junggar Basin and Mongolian Plateau [N2]) regions. AMOVA analysis demonstrated that over 76% of the observed genetic variation was related to these lineage splits, indicating substantial genetic differentiation among the four lineages. A strong pattern of isolation-by-distance across the sampling populations suggested that geographic distance principally shaped the genetic structure. The four lineages diverged by 0.9–2.2% for the concatenated data, which were estimated to have coalesced ~1.17 million years ago (Mya), suggesting that the expansions of the Badain Jaran, Tengger, and Mu Us deserts during the Xixiabangma glaciation likely interrupted gene flow and triggered the observed divergence in the southern and northern regions. Subsequently, the early Pleistocene integration of the Yellow River and associated deserts expansion promoted the differentiation of S1 and S2 lineages (~0.9 Mya). Both mitochondrial evidence and ecological niche modeling (ENM) reject the signature of demographic and range contractions during the LGM for G. cognatus. In addition, ENM predicts that the suitable habitat of G. cognatus will contract in the future. As such, the conservation and management of ESUs should be a priority. Our findings provide the first insights on the lineage diversification and population dynamics of the Alashan pit viper in relation to geological history and Pleistocene climatic oscillations in arid Northwest China. Full article

The genetic structure and demographic history of marine organisms are influenced by biological and ecological features, oceanic currents, and the paleo-geological effects of sea-level fluctuations. In this study, we used mitochondrial COI + 16S gene analysis to investigate the phylogeographic pattern and demography of Monodonta labio and M. confusa in Taiwan, the Ryukyu Islands, Japan, mainland China, and Korea. Our genetic analysis identified two major lineages that were not evident from the distribution patterns of different populations. The Taiwan Strait, which acted as a land bridge during Pleistocene glaciations, and the lack of strong dispersal barriers to gene flow between ocean basins after glaciations shaped the phylogeographic pattern. The genetic differentiation in the Ryukyu Islands was influenced by the specialist-generalist variation hypothesis and the Kuroshio Current. Bayesian skyline plot analyses suggested that the effective population size of M. labio and M. confusa rapidly increased approximately 0.1 and 0.075 million years ago, respectively. Our approximate Bayesian computation analysis suggested that all M. labio and M. confusa populations experienced a decline in population size following a recent population expansion and constant size, respectively. Our study provides a baseline for future investigations of the biogeographical patterns of marine gastropods in the Northwest Pacific and offers valuable insights for the management, sustainable resource utilization, and conservation of this species. Full article

Pleistocene glaciations had profound impact on the spatial distribution and genetic makeup of species in temperate ecosystems. While the glacial period trapped several species into glacial refugia and caused abrupt decline in large populations, the interglacial period facilitated population growth and range expansion leading to allopatric speciation. Here, we analyzed 40 genomes of four species of ibex and found that Himalayan ibex in the Pamir Mountains evolved independently after splitting from its main range about 0.1 mya following the Pleistocene species pump concept. Demographic trajectories showed Himalayan ibex experienced two historic bottlenecks, one each c. 0.8–0.5 mya and c. 50–30 kya, with an intermediate large population expansion c. 0.2–0.16 mya coinciding with Mid-Pleistocene Transitions. We substantiate with multi-dimensional evidence that Himalayan ibex is an evolutionary distinct phylogenetic species of Siberian ibex which need to be prioritized as Capra himalayensis for taxonomic revision and conservation planning at a regional and global scale. Full article