Search

The mountains in the Atlantic Forest domain are environments that harbor a high biodiversity, including species adapted to colder climates that were probably influenced by the climatic variations of the Pleistocene. To understand the phylogeographic pattern and assess the taxonomic boundaries between two sister montane species, a genomic study of the butterflies Actinote mantiqueira and A. alalia (Nymphalidae: Acraeini) was conducted. Analyses based on partial sequences of the mitochondrial gene COI (barcode region) failed to recover any phylogenetic or genetic structure discriminating the two species or sampling localities. However, single nucleotide polymorphisms gathered using Genotyping‐by‐Sequencing provided a strong isolation pattern in all analyses (genetic distance, phylogenetic hypothesis, clustering analyses, and FST statistics) which is consistent with morphology, separating all individuals of A. alalia from all populations of A. mantiqueira. The three sampled mountain ranges where A. mantiqueira populations occur—Serra do Mar, Serra da Mantiqueira, and Poços de Caldas Plateau—were identified as three isolated clusters. Paleoclimate simulations indicate that both species' distributions changed according to climatic oscillations in the Pleistocene period, with the two species potentially occurring in areas of lower altitude during glacial periods when compared to the interglacial periods (as the present). Besides, a potential path between their distribution through the Serra do Mar Mountain range was inferred. Therefore, the Pleistocene climatic fluctuation had a significant impact on the speciation process between A. alalia and A. mantiqueira, which was brought on by isolation at different mountain summits during interglacial periods, as shown by the modeled historical distribution and the observed genetic structure. [ABSTRACT FROM AUTHOR]

Late Pleistocene glacial terminations are caused by rising atmospheric CO2 occurring in response to atmospheric and ocean circulation changes induced by increased discharge from Northern Hemisphere ice sheets. While climate records place glacial terminations coincident with decreasing orbital precession, it remains unclear why a specific precession minimum causes a termination. We compare the orbital and ice volume configuration at each precession minima over the last million years to demonstrate that eccentricity, through its control on precession amplitude, period and coherence with obliquity, along with ice sheet size, determine whether a given precession minimum will cause a termination. We also demonstrate how eccentricity controls obliquity maxima and precession minima coherence, varying the duration of glaciations. Glaciations lasting ∼100 thousand years are controlled by Earth's eccentricity cycle of the same period, while the shortest (20–40 ka) and longest (155 ka) occupy the maxima and minimums of the 400 thousand year eccentricity cycle. Plain Language Summary: The Milankovitch theory of the ice ages predicts that the growth and collapse of Pleistocene ice sheets is paced by the cycles in high latitude solar insolation that accompany variations in Earth's orbital motion. The orbital modes that dominate frequencies of incoming solar radiation are obliquity and precession, which operate at periodicities of approximately 40 and 20 thousand years, respectively. The dominant frequency at which ice sheets grow and collapse over the last million years is, however, approximately 100 thousand years, a closer match to eccentricity, an orbital period near absent from past solar radiation. Through a comparison between Earth's orbital configuration and an approximation of past global ice volume, we identify that the precession minima that trigger ice sheet collapse occur at distinct configuration of eccentricity and ice sheet size. In most cases terminations occur when precession minima align with obliquity maxima. We find that this coherence is influenced by the duration of precession cycles, which is in turn controlled by eccentricity. From these observations, we conclude that orbital eccentricity, through its control on both the amplitude and period of precession, paces the timing of glacial terminations and the size of Late Pleistocene ice sheets. Key Points: Late Pleistocene glacial terminations occur at distinct configurations of orbital precession, obliquity, eccentricity and ice volumeEccentricity controls the duration of precession cycles, and therefore the coherence of obliquity and precessionOrbital eccentricity, through its control on the amplitude and period of precession, paces Late Pleistocene glaciations [ABSTRACT FROM AUTHOR]

[Display omitted] • Gaining parthenogenetic metacercariae (PM) led to a burst of speciation in the genus Parvatrema. • Evolution of Parvatrema with PM, the free-swimming cercarial stage was lost and the number of PM generations stabilized. • The relationship between PM and second intermediate hosts evolved from inhabiting the extrapallial space to endoparasitism. • Parvatrema with PM likely expanded from the North Pacific to the North Atlantic in the Pleistocene epoch. • Parvatrema with PM could serve as a model of early stages in digenean evolution. There are several species of gymnophallid digeneans in the genus Parvatrema that are unique in developing metacercariae that reproduce by parthenogenesis in the second intermediate host. Transmission of these digeneans takes place in coastal ecosystems of the North Pacific and North Atlantic seas. The first intermediate hosts are bivalves, the second ones are gastropods, and the definitive hosts are migratory birds. We integrated data accumulated over 25 years of research and differentiated a complex of five closely related species. They differ in the molluscan second intermediate hosts, distribution ranges, and life cycles patterns. The type I life cycle includes two generations of parthenogenetic metacercariae, followed by development of metacercariae which are invasive for the definitive host. In the type II life cycle, the number of generations of parthenogenetic metacercariae is unlimited, and they can also produce cercariae. These cercariae emerge into the environment and can infect new individuals of the second intermediate host. We conclude that the type I life cycle is a derived option that has evolved as a better fit to transmission in the unstable conditions in the intertidal zone. Another evolutionary trend in Parvatrema is transition from inhabiting the extrapallial space of the gastropod second intermediate host to endoparasitism in its mantle and internal organs. rDNA sequence analysis highlighted that Parvatrema spp. with parthenogenetic metacercariae form a monophyletic clade and suggested the Pacific origin of the group, with two transfers to the North Atlantic and colonisation of new second intermediate host species. Apparently the group formed in the late Pliocene-Pleistocene and diversified as a result of recurrent isolation in inshore refugia during glacial periods. We argue that parthenogenetic metacercariae in Parvatrema may serve as a model for early digenean evolution, demonstrating the first steps of adopting the molluscan first intermediate host and becoming tissue parasites. [ABSTRACT FROM AUTHOR]

Pleistocene climatic oscillations exerted significant influences on the genetic structure and demography of rhesus macaque (Macaca mulatta) in eastern China. However, the evolutionary history of rhesus macaques in subtropical and temperate China remained unclear and/or controversial. Herein, we analyzed the autosomes, mitochondrial genomes, and Y‐chromosomes from 84 individuals of Chinese rhesus macaque. The results revealed that (1) all individuals were clustered into pan‐west and pan‐east genetic groups, which exhibited Shaanxi Province as the northernmost region of western dispersal route of rhesus macaques in China; (2) in subtropical and temperate China, rhesus macaques were divided into four lineages (TH, DB, HS, and QL), and their divergence times corresponded to the Penultimate Glaciation (300–130 kya) and Last Glaciation (70–10 kya), respectively; (3) the individuals from Mt. Taihangshan (TH) are closely related to individuals from Mt. Dabashan (DB) in the autosomal tree, rather than individuals from Mt. Huangshan (HS) as indicated by the mitogenome tree, which supports the hypothesis that the ancestral rhesus macaques radiated into Mt. Taihangshan from Mt. Huangshan via Mt. Dabashan; and (4) the demographic scenario of the four lineages showed the ancestral rhesus macaques bottleneck and expansion corresponding to the suitable habitat reduction and expansion, which confirmed they had experienced northward recolonization and southward retreat events from Mt. Huangshan area via Northern China Plain to Northernmost China along with Pleistocene glacial cycles. This study provides a new insight into understanding how Pleistocene glaciation has influenced faunal diversity in subtropical and temperate China, especially for those exhibiting differential patterns of sex dispersal. [ABSTRACT FROM AUTHOR]

This research was carried out in north-central Poland, which was occupied by the ice sheet of the Saalian (Marine Isotope Stage [MIS] 6) and Upper Stadial of the Weichselian (MIS 2) glaciation. The application of the anisotropy of magnetic susceptibility (AMS) method supported by a digital elevation model (DEM) analysis of the orientation of glacial landforms allowed for the reconstruction of ice-sheet extent and ice movement directions of these two Pleistocene glaciations. The research used an innovative method of collecting AMS till samples from the glacial plateau areas. Based on the research, it was found that during the general recession of the ice sheet of the Saalian glaciation, a previously undescribed glacial transgression occurred, characterized by a different direction of ice-sheet movement. On the basis of detailed geomorphological studies of the area of terminal moraines, previously described in fragments, the maximum extent of the ice sheet during the Weichselian glaciation was clarified. The recession of the ice sheet of the Weichselian glaciation from the area of north-central Poland took place in four regressive or transgressive–regressive stages with variable directions of ice-sheet movement. The results obtained indicate the great potential of the AMS method in paleoenvironmental studies of glaciated areas. [ABSTRACT FROM AUTHOR]

We present the glacial history of the Makarov Basin (western Arctic Ocean) during the last ∼1.1 Myr, with sediment provenances using the newly refined chronostratigraphy of core ARA03B‐41GC02. According to the principal component analysis of the bulk mineral assemblages, felsic minerals were dominant, and their ratios (K‐feldspar/plagioclase and quartz/feldspars) indicated that sediment supply to the Makarov Basin was mainly from the Siberian margin and partly from northern North America, including the Canadian Arctic. However, their occurrence did not vary significantly between interglacials and glacials due to the mixed sources. In contrast, clinopyroxene and dolomite indicated specific sediment origins from the eastern Siberian margin and northern North America, respectively. The clinopyroxene content followed an eccentricity cycle (∼100‐Kyr) during the early to middle Pleistocene, suggesting that the eustatic sea level changes may have influenced its input from the eastern Siberian margin. The dolomite, transported primarily by icebergs from the Arctic sector of the Laurentide Ice Sheet (LIS) in northern North America, has also followed the same cycle since the early Pleistocene. Thus, the mineralogical signals highlight that sediment origins and transport processes in the Makarov Basin were related to ice sheet evolution at the eccentricity cycle. In addition, dolomite deposition in the Makarov Basin began by the early Pleistocene (∼790 ka), ∼150 ka earlier than in previous North Atlantic records (∼640 ka), indicating the earlier LIS calving in the Arctic sector than in the Atlantic sector. Plain Language Summary: We investigated past mineralogic changes in the Makarov Basin (western Arctic Ocean) over the last 1.1 million years using marine sediment core ARA03B‐41GC02. Bulk mineral analysis revealed that sediments in the Makarov Basin mainly originated from the Siberian margin, with a partial contribution from northern North America. However, sediments deposited during interglacial and glacial periods were mixed from different sources. Nevertheless, specific minerals such as clinopyroxene and dolomite allow us to distinguish different sediment sources between the eastern Siberian margin and northern North America. The clinopyroxene content fluctuated on a cycle of ∼100‐Kyr during the early to middle Pleistocene, suggesting an association with global sea level changes. The variation in dolomite content followed the same cycle, indicating that sediments containing dolomite were mainly transported by icebergs from the Laurentide Ice Sheet (LIS) in northern North America. These results linked sediment sources and transport processes to glacier evolution over cycles of ∼100‐Kyr. Interestingly, our study shows that dolomite deposition in the Makarov Basin began about 790,000 years ago, which is about 150,000 years earlier than previously reported (∼640 ka) in the North Atlantic, suggesting an earlier LIS calving into in the Arctic sector than in the North Atlantic sector. Key Points: Sediment provenances of clinopyroxene and dolomite are different (eastern Siberian margin and North America) in the Makarov BasinVariations in dolomite and clinopyroxene during the Pleistocene follow a ∼100 Kyr cycle of eccentricityDolomite in Makarov Basin ∼150 Kyr earlier than N. Atlantic implies Laurentide Ice Sheet calved into Arctic before extending to N. Atlantic [ABSTRACT FROM AUTHOR]

This study presents the results of a 2D numerical basin and petroleum systems model of the Olga Basin in the NW Barents Sea offshore northern Norway, a frontier exploration area in which there are abundant seafloor oil and gas seepages. The effects of Pleistocene ice sheet advances on rock properties and subsurface fluid migration in this area, and on seafloor hydrocarbon seepage, are not well understood. The 2D numerical model takes account of recurrent ice advances and retreats, together with related erosional and temperature effects, and investigates the influence of these parameters on fluid migration. Model results show that Pleistocene glaciations reduced the temperature in the sedimentary succession in the Olga Basin by up to 20 °C, for example in the uppermost Cretaceous and Jurassic sediments which underlie the seafloor down to a depth of 0.5 to 1 km. The decrease in temperature was in general predominantly related to the intensity of glacial erosion, which was set in this study to a depth of 600 m based on previous studies. Hydrocarbon fluids expelled from potential thermogenic source rocks of Carboniferous to Triassic ages on the SW margin of the Olga Basin migrated to the seafloor through permeable carrier beds. However, fluid migration to the surface in the NE of the study area took place along fault conduits. In a closed fault model scenario, only 0.3 Mt of hydrocarbons are modelled to have migrated along the 0.5 km wide model section; in a second scenario with partially open faults, about 22 Mt of hydrocarbons, representing about 11% of the total hydrocarbons generated by potential thermogenic source rocks in the study area, were lost to the surface during the Pleistocene. The potential for microbial methane generation in the Olga Basin was limited both during the Pleistocene and at the present day due to the significant reduction in temperature during glacial episodes, and due to the intense glacial‐related erosion of the Mesozoic to Cenozoic stratigraphy. During glacial stages, the gas hydrate stability zone beneath the ice sheet is modelled to have extended to a depth of up to 900 m for a pure methane composition, and to a depth of up to 1100 m for a possible thermogenic‐sourced mixed gas composition of 90% methane, 7% propane and 3% ethane. Gas hydrates with this mixed composition are modelled to have been stable in the Olga Basin during the last three glacial advances and into the present. These modelling results provide an insight into the key factors controlling the migration and surface leakage of hydrocarbon fluids in the Olga Basin region, and into the effects of glaciations on rock properties in a glaciated basin. [ABSTRACT FROM AUTHOR]

To describe the composition of the penultimate glacial Brazilian Atlantic forest, we analyzed pollen, charcoal and diatoms deposited in the section from 871 to 1400 cm of core CO14 drilled in the Colônia basin in southeastern Brazil. The landscape was characterized by a cool grassland with three conifer genera: Araucaria, Podocarpus and Ephedra. Total arboreal pollen frequency did not change during the transition from glacial to interglacial conditions. Changes in Podocarpus frequency and concentration showed out‐of‐phase responses with austral summer insolation at an orbital scale while, at a millennial scale, both northern and southern hemisphere ice volume controlled the interplay between positions of the Inter‐Tropical Convergence Zone and South Tropical Front (STF), which in turn defined the latitudinal distribution of rainfall. The disappearance of Podocarpus and the decrease of Araucaria observed between ~167 and 160 ka were related to a dry interval which was not observed elsewhere. During Termination II a progressive decrease in conifer pollen taxa was in phase with a southward shift in the STF and increase in Atlantic sea surface temperatures. Our results show that southern hemisphere conifer distribution is strongly linked to austral summer insolation and winter precipitation and will be threatened by the southward expansion of the summer rainfall boundary. [ABSTRACT FROM AUTHOR]

The Yarlung Tsangpo River on the southern Tibetan Plateau flows between alternating broad shallow valley and deep gorge sections. Many damming events caused by glaciers or glacial moraines have occurred in the gorges during the last glacial period, which play an important role in shaping river landscapes. In this study, we used geomorphological, sedimentological and chronological techniques to analyze the dammed paleolake in the Shan'nan-Gyaca stretch of the middle reaches of the Yarlung Tsangpo River. Four sedimentary sections were studied, delineating three major lithofacies associations. We also summarized previous research. Our results suggest that the paleolake was formed before ∼16 ka BP and drained at ∼10 ka BP, developing at least two deltaic-lacustrine sedimentary cycles. The paleolake's highest water surface was ∼3620 m above sea level, with a minimum area and volume of ∼140 km2 and ∼86 km3, respectively. The dam located at the entrance of the Gyaca Gorge may have been formed by glacial moraines during the Last Glacial Maximum; the subsequent outburst event had probably triggered a megaflood downstream. [ABSTRACT FROM AUTHOR]

Aim: The Neotropics constitute the most biodiverse region of the world, yet its patterns of diversification and speciation differ among Neotropical areas and are not equally well understood. Particularly, avian evolutionary processes are understudied in the open habitats of temperate South America, where the role of glacial cycles is not clear. We analysed the evolutionary history of a Neotropical widespread bird species as a case study to evaluate its continental‐scale patterns and processes of diversification, with a focus on Patagonia. Location: Open habitats of the Neotropics. Taxon: Vanellus chilensis (Aves, Charadriiformes). Methods: We obtained reduced representation genomic and mitochondrial data from the four subspecies of V. chilensis to perform a phylogenetic/phylogeographical analysis and study the evolutionary history of the species. We complemented these analyses with the study of vocalizations, a reproductive signal in birds. Results: The initial diversification event within V. chilensis, approximately 600,000 years ago, split a Patagonian lineage from one containing individuals from the rest of the Neotropics. We found considerable gene flow between these two lineages and a contact zone in northern Patagonia, and showed that genomic admixture extends to northwestern Argentina. Shallower divergence was detected between the two non‐Patagonian subspecies, which are separated by the Amazon River. Vocalizations were significantly different between the two main lineages and were intermediate in their temporal and frequency characteristics in the contact zone. Main Conclusions: Patagonian populations of V. chilensis are clearly differentiated from those of the rest of the Neotropics, possibly as a consequence of Pleistocene glaciations. A secondary contact zone in northern Patagonia with extensive gene flow among lineages appears to be the consequence of post‐glacial, northward expansion of the Patagonian populations. Future analyses focused on the dynamics of the contact zone will allow us to establish whether the species continues to diverge or is homogenizing. [ABSTRACT FROM AUTHOR]

We review the major phylogeographic patterns in Aotearoa New Zealand's terrestrial flora and fauna that have been associated with the Ōtira Glaciation of the Pleistocene, the end of which coincides with the global Last Glacial Maximum (LGM). We focus on (1) the complexity of biogeographic histories of New Zealand species, with LGM-driven phenomena overlaying the impacts of mountain-building and other drivers of phylogeographic structure; (2) the locations of glacial refugia and sets of taxa which may have shared refugia; and (3) the role of glaciation in driving diversification. We end with a brief focus on the next directions, including what can we learn about New Zealand's glacial history by expanding our phylogeographic toolbox to include genomic methods and hypothesis-driven inference methods. We provide follow-up questions which take advantage of the wealth of phylogeographic data for New Zealand. [ABSTRACT FROM AUTHOR]

The debate over isostatic uplift versus discharge as drivers of Quaternary river incision is explored here through geospatial analysis of a ~250‐m‐relief terrace sequence from the Río Pinturas (Argentine Patagonia). The geomorphic setting of the Cañadon Caracoles reach allows evaluation of discharge as a driver of terrace incision because advancing ice during Pleistocene glaciations blocked Pacific drainage and routed meltwater from an expanded ~104‐km2 catchment to the Atlantic through the dryland steppe of the study area. Twenty‐two terrace levels, some assigned to previously dated ice margins [Marine Isotope Stage (MIS) 32–36, MIS 16, MIS 8 and MIS 2], were identified. Average net incision since 800 ka (~0.34 m ka−1) exceeded regional uplift rates. The MIS 2 terraces, with ante quem and post quem age constraint on the timing of terrace formation, show that terrace incision was episodic and faster still during a transitional warming climate. Glacier recession and proglacial lake formation at ~18 ka led to rapid incision of ~11.7 m ka−1 over a few millennia. River capture and negligible flow from ~15.0 ka caused fan‐dammed lake formation on the valley floor and vertical stability during MIS 1. The Pinturas terraces demonstrate rapid incision can be driven by discharge and sediment dynamics. [ABSTRACT FROM AUTHOR]

The Balkans are considered a major glacial refugium where flora and fauna survived glacial periods and repopulated the rest of Europe during interglacials. While it is also thought to have harboured Pleistocene human populations, evidence linking human activity, paleoenvironmental indicators and a secure temporal placement to glacial periods is scant. Here, we present the first intra-tooth multi-isotope analysis for the European straight-tusked elephant Palaeoloxodon antiquus, on an adult male individual excavated in association with lithic artefacts at the MIS 12 site Marathousa 1 (Megalopolis basin, Greece). The studied find also exhibits anthropogenic modifications, providing direct evidence of hominin presence. We employed strontium, carbon and oxygen isotope analysis on enamel bioapatite to investigate its foraging and mobility behaviour, using a sequential sampling strategy along the tooth growth axis of the third upper molar, to assess ecological changes during the last decade of life. We found a geographically restricted range, in a C3-dominated open woodland environment, and relatively stable conditions over the examined timeframe. Our results show that, despite the severity of the MIS 12 glacial, the Megalopolis basin sustained a mesic habitat, sufficient plant cover and limited seasonal fluctuations in resource availability, pointing to its role as a glacial refugium for both fauna and hominins. [ABSTRACT FROM AUTHOR]

The aim of the study is the reconstruction of paleoclimatic patterns in the formation of the Chumbur-Kosa (MIS-17.MIS-1) loess–soil sequences and the assessment of the possibility of using phytolithic analysis to reconstruct the vegetation cover in the interglacial and glacial periods of the Pleistocene. Mean annual precipitation was calculated using the magnetic susceptibility. It has been established that in the Pleistocene there was a directed climate change towards aridization, in which the amount of precipitation during the interglacial periods decreased from 600 to 550 mm/year, and during the glacial periods it did not exceed 200–250 mm/year. Aridization of the climate led to xerophytization of plant communities, a decrease in bioproductivity and landscape diversity. In the warm periods of the Pleistocene, meadow–forb associations prevailed, which were replaced by steppe associations at the onset of the glacial stage. Natural and climatic zones were within the modern boundaries, demonstrating the relative stability of the steppe landscapes to global climatic fluctuations. [ABSTRACT FROM AUTHOR]

Simple Summary: One of the main differences between the modern fauna of steppe and desert-steppe insects and the similar fauna of the Last Ice Age is the current leading position of darkling beetles (Coleoptera, Tenebrionidae), which are represented in fossil faunas only by singletons. We hypothesize that the reason lies in the insufficient cold resistance of these insects for successful overwintering. We studied the cold resistance of adults from five species of darkling beetles from the Altai Mountains that overwinter in the soil and the larvae from one such species. The ranges of three of these are limited from the north by the desert-steppe margin of Central Asia with extremely low air temperatures. More than 50% of individuals of these species in the experiment did not withstand cooling below −22 °C. Temperatures in the soil of natural habitats at a depth of 10 cm are close to or lower than the above values. Overwintering is therefore possible in places with greater snow thickness (hollows, wind shade of shrubs and large cereals). Since darkling beetles are now on the border of temperature resistance in the Altai, they likely did not exist in the much more severe conditions of the glacial periods in the Altai Mountains, West Siberian Plain, and Northeast Asia. The level of diversity and abundance of darkling beetles (Coleoptera, Tenebrionidae) is the main difference between the late Pleistocene and modern insect faunas of arid regions. In the Pleistocene assemblages they are extremely rare, whereas in the modern ones they predominate. It is assumed that the reason for their rarity in fossil entomological complexes is their lack of cold resistance. The supercooling points (SCP) and low lethal temperatures (LLT) of adults from five species of Altai darkling beetles that overwinter in the soil and larvae from one such species were measured in the laboratory. All beetles supercooled at negative temperatures but could not survive freezing, with the average SCP of the most cold-resistant species between −25.7 and −21.7 °C (Bioramix picipes, Anatolica dashidorzsi, and Penthicus altaicus). However, 50% of the individuals from different species in the experiment died after exposure during two days at temperatures ranging from −22 to −20 °C. The focal species are distributed in parts of Central Asia with an extreme continental climate, and the temperatures measured in the soil of these natural areas turned out to be lower than or close to the limit of cold resistance of the beetles. Overwintering of darkling beetles is therefore only possible in areas with deep snow: in hollows, under bushes, and under large cereals. Darkling beetles with poor cold resistance could not have existed in the colder climate of the late Pleistocene, which explains their absence from fossil fauna. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the genetic diversity and relationships among Apodemus mystacinus lineages by analyzing mitochondrial Cytochrome b sequences. The study included samples from Iranand south east Turkey (Hakkari and Şırnak), in addition to previously studied populations. The results showed differences in the relationships among lineages and the structure of the phylogenetic tree compared to previous studies. A. m. mystacinus lineage, represented by samples from southwest Anatolia and Crete, was located at the base of the tree. The Iranian specimens were clustered with the southeastern specimens of Turkey in a separate lineage, indicating a possible refugium for A. mystacinus populations during glacial periods. The study also suggested that the expansion of A. mystacinus into Anatolia and neighboring regions during the Pleistocene facilitated its colonization of the Aegean islands. The differentiation between A. m. euxinus lineage and the south east Anatolia-Iran lineage may have resulted from the ancestral population in eastern Turkey diverging into two different lineages with one expanding its range towards the Black Sea and the other migrating towards the Zagros Mountains in Iran. These findings contribute to the understanding of the evolutionary history and phylogeography of A. mystacinus in its main range. [ABSTRACT FROM AUTHOR]

During the Late Pleistocene, the Palaeo-Ems system (PES) was one of the major tributary channels feeding the Elbe Palaeovalley (EPV) and formed an important part of the drainage system of the continental northwestern Europe unglaciated hinterland. In this study, a detailed interpretation of high-resolution 2D sub-bottom profiler and Boomer grids were used to map the overall course of the submerged PES channel, as well as its spatial and stratigraphic relationships with other Quaternary geological units in the German North Sea. Mapping of buried tunnel valleys, a lacustrine-fill unit, straight channel structures was also carried out. The sedimentary record of the PES is represented by a low gradient and meandering channel which branched into two major pathways as it approached the EPV western flank. Its upstream to downstream trends, coupled with seaward decreasing gradient and sinuosity, are similar to those visible in present-day river deltas. Both the PES and EPV subsequently formed a combined depositional system, which was successively drowned due to the fast-rising relative sea level that overwhelmed the adaptation capabilities of the joint drainage system. For the first time, this study sheds light onto the PES/EPV morpho-stratigraphic relationships which played a key role in the coastal landscape architecture of the German North Sea since the Late Pleistocene. [ABSTRACT FROM AUTHOR]

We explore the spatial and temporal variations in denudation rates in the northern Pamir—Tian Shan region using 10Be‐derived denudation rates from modern (n = 110) and buried sediment (2.0–2.7 Ma; n = 3), and long‐term exhumation rates from published apatite fission track (AFT; n = 705) and apatite (U‐Th‐Sm)/He (AHe; n = 211) thermochronology. We found moderate correlations between denudation rates and topographic metrics and weak correlations between denudation rates and annual rainfall, highlighting complex linkages among tectonics, climate, and surface processes that vary locally. The 10Be data show a spatial trend of decreasing modern denudation rates from west to east, suggesting that deformation and precipitation control denudation in the northern Pamir and western Tian Shan. Farther east, the denudational response of the landscape to Quaternary glaciations is more pronounced and reflected in our data. Modern 10Be denudation rates are generally higher than the long‐term AFT and AHe exhumation rates across the studied area. In the Kyrgyz Tian Shan, on average, the highest 10Be denudation rates are recorded in the Terskey range, south of Lake Issyk‐Kul. Here, modern denudation rates are higher than 10Be‐derived paleo‐denudation rates, which are comparable in magnitude with the long‐term exhumation rates inferred from AFT and AHe. We propose that denudation in the region, particularly in the Terskey range, remained relatively steady during the Neogene and early Pleistocene. Denudation increased due to glacial‐interglacial cycles in the Quaternary, but this occurred after the onset and intensification of the Northern Hemisphere glaciations at 2.7 Ma. Plain Language Summary: Tectonic forces create mountains, while climatically modulated erosion breaks them down into sediment that rivers carry to the final depositional basin. This cycle affects global climate over long periods, but it's unclear whether mountain uplift causes climate change or if climate cooling leads to faster erosion and mountain uplift. To tackle these questions, we explore temporal and spatial changes in rates of denudation in the northern Pamir—Tian Shan region and find that rates remained steady during the Neogene and early Pleistocene but increased due to glacial‐interglacial cycles in the Quaternary. We also find that modern denudation rates decrease from west to east. This suggests that tectonic deformation controls denudation in the northern Pamir and western Tian Shan, while further east the denudational response of the landscape to Quaternary glaciations is more pronounced and reflected in our data. Dominant controls on modern denudation rates vary across the mountain range and reflect local factors. Our results highlight how the evolution of mountain belts strongly depends on denudation, which reflects complex interactions between tectonics, climatic changes, and surface processes, and show how in the northern Pamir—Tian Shan region, climate cooling during the Quaternary period resulted in faster erosion rates. Key Points: Modern denudation rates are higher than paleo‐denudation rates from 2.0 to 2.7 Ma and exhumation rates inferred from thermochronologyDenudation in the Terskey range remained steady during the Neogene and early Pleistocene and then increased in the Quaternary after 2.0 MaThe denudational response to Quaternary glaciations is detectable in the Kyrgyz and Chinese portions of the Tian Shan [ABSTRACT FROM AUTHOR]

We introduce a new hypothesis concerning the role of internal climate dynamics in the non‐linear transitions from interglacial to glacial (IG‐G) state since the Mid Pleistocene Transition (MPT). These transitions encompass large and abrupt changes in atmospheric CO2, ice volume, and temperature that we suggest involve critical interactions between insolation and high amplitude oscillations in ocean/atmosphere circulation patterns. Specifically, we highlight the large amplitude of millennial‐scale climate oscillations across the transition from Marine Isotope Stage (MIS) 5 to 4, which we argue led to amplified cooling of the deep ocean and we demonstrate that analogous episodes of extreme cooling systematically preceded glacial periods of the last 800 kyr. We suggest that such cooling necessitates a reconfiguration of the deep ocean to avoid a density paradox between northern and southern‐sourced deep waters (SSW), which could be accomplished by increasing the relative volume and or salinity of SSW, thus providing the necessary storage capacity for the subsequent (delayed) and relatively abrupt drawdown of CO2. We therefore explain the transient decoupling of Antarctic temperature from CO2 across MIS 5/4 as a direct consequence of millennial activity at that time. We further show that similar climatic decoupling typically occurred during times of low obliquity and was a ubiquitous feature of IG‐G transitions over the past 800 kyr, producing the appearance of bimodality in records of CO2, benthic δ18O and others. Finally we argue that the apparent lack of bimodality in the pre‐MPT record of benthic δ18O implies that the dynamics associated with IG‐G transitions changed across the MPT. Key Points: Extreme interstadial‐like millennial‐scale Antarctic cooling systematically preceded transitions to a glacial state throughout the past 800 kyrSuch cooling could promote glacial ocean stratification by volume expansion and or salinification of southern‐sourced deep watersThese dynamics can explain the abrupt nature of interglacial‐glacial changes in for example, CO2 since the Mid Pleistocene Transition but apparently not before [ABSTRACT FROM AUTHOR]

During the last glacial period, rapidly changing environments posed substantial challenges to Neanderthal populations in Europe. Southern continental regions, such as Iberia, have been proposed as important climatic "buffer" zones during glacial phases. Contextualising the climatic and ecological conditions Neanderthals faced is relevant to interpreting their resilience. However, records of the environments and ecosystems they exploited across Iberia exhibit temporal and spatial gaps in coverage. Here we provide new evidence for palaeotemperatures, vegetation structure, and prey herbivore ecology during the late Pleistocene (MIS 5-3) in northern Spain, by applying multiple stable isotope tracers (δ18O, δ13C, δ15N, δ34S) to herbivore skeletal remains associated with Neanderthal occupations at Axlor Cave, Bizkaia. The results show little change over time and indicate stable climatic conditions and ecosystems across different occupations. Large within-layer isotopic variability in nitrogen and sulphur suggests the presence of a mosaic environment and a variety of isotopic ecotones that were exploited by Neanderthals and their prey. We implement a combination of carbonate and phosphate δ18O measurements to estimate palaeotemperatures using a cost-effective workflow. We show that the targeted use of phosphate δ18O measurements to anchor summer peak and winter trough areas enables high-precision seasonal palaeoclimatic reconstructions. [ABSTRACT FROM AUTHOR]

Although most ancient DNA studies have focused on the last 50,000 years, paleogenomic approaches can now reach into the early Pleistocene, an epoch of repeated environmental changes that shaped present-day biodiversity. Emerging deep-time genomic transects, including from DNA preserved in sediments, will enable inference of adaptive evolution, discovery of unrecognized species, and exploration of how glaciations, volcanism, and paleomagnetic reversals shaped demography and community composition. In this Review, we explore the state-of-the-art in paleogenomics and discuss key challenges, including technical limitations, evolutionary divergence and associated biases, and the need for more precise dating of remains and sediments. We conclude that with improvements in laboratory and computational methods, the emerging field of deep-time paleogenomics will expand the range of questions addressable using ancient DNA. [ABSTRACT FROM AUTHOR]

Intraspecific genetic diversity is a key aspect of biodiversity. Quaternary climatic change and glaciation influenced intraspecific genetic diversity by promoting range shifts and population size change. However, the extent to which glaciation affected genetic diversity on a global scale is not well established. Here we quantify nucleotide diversity, a common metric of intraspecific genetic diversity, in more than 38,000 plant and animal species using georeferenced DNA sequences from millions of samples. Results demonstrate that tropical species contain significantly more intraspecific genetic diversity than nontropical species. To explore potential evolutionary processes that may have contributed to this pattern, we calculated summary statistics that measure population demographic change and detected significant correlations between these statistics and latitude. We find that nontropical species are more likely to deviate from neutral expectations, indicating that they have historically experienced dramatic fluctuations in population size likely associated with Pleistocene glacial cycles. By analyzing the most comprehensive data set to date, our results imply that Quaternary climate perturbations may be more important as a process driving the latitudinal gradient in species richness than previously appreciated. [ABSTRACT FROM AUTHOR]

The oldest known hominin remains in Europe [~1.5 to ~1.1 million years ago (Ma)] have been recovered from Iberia, where paleoenvironmental reconstructions have indicated warm and wet interglacials and mild glacials, supporting the view that once established, hominin populations persisted continuously. We report analyses of marine and terrestrial proxies from a deep-sea core on the Portugese margin that show the presence of pronounced millennial-scale climate variability during a glacial period ~1.154 to ~1.123 Ma, culminating in a terminal stadial cooling comparable to the most extreme events of the last 400,000 years. Climate envelope-model simulations reveal a drastic decrease in early hominin habitat suitability around the Mediterranean during the terminal stadial. We suggest that these extreme conditions led to the depopulation of Europe, perhaps lasting for several successive glacial-interglacial cycles. [ABSTRACT FROM AUTHOR]

Simple Summary: Previous paleoclimatic modelling studies on the European whip snake, Hierophis viridiflavus, hardly explain its genetic structure. Through the combination of phylogeographic and paleoclimatic modelling analyses, we reconstructed the biogeographic history of the species. Phylogeographic analyses recovered two major lineages that had diversified in different ways in the late Pleistocene. Paleoclimatic models unveiled the species range dynamics since the late Pleistocene, showing major range contractions into multiple climatic refugia in Southern Europe during glacial and interglacial events, as well as more recent northwards expansions. This study contributes to our knowledge of H. viridiflavus' historical biogeography and sheds more light on the evolutionary processes that took place in the Mediterranean Basin hotspot. Phylogeographic and paleoclimatic modelling studies have been combined to infer the role of Pleistocene climatic oscillations as drivers of the genetic structure and distribution of Mediterranean taxa. For the European whip snake, Hierophis viridiflavus, previous studies based on paleoclimatic modelling have depicted a low reliability in the pattern of past climatic suitability across the central Mediterranean Basin, which barely fits the species' genetic structure. In this study, we combined phylogeographic and paleoclimatic modelling tools to improve our understanding of the biogeographic history of H. viridiflavus, particularly extending the sampling and phylogeographic inferences to previously under-sampled regions. Phylogeographic analyses recovered two major clades that diverged at the beginning of the Pleistocene and had diversified in different ways by the late Pleistocene: the east clade (composed of three subclades) and the west clade (with no further structure). Paleoclimatic models highlighted the temperate character of H. viridiflavus, indicating range contractions during both the last inter-glacial and last glacial maximum periods. Range expansions from southern-located climatic refugia likely occurred in the Bølling–Allerød and Middle Holocene periods, which are supported by signals of demographic growth in the west clade and South–East–North subclade. Overall, this work improves our understanding of the historical biogeography of H. viridiflavus, providing further insights into the evolutionary processes that occurred in the Mediterranean Basin hotspot. [ABSTRACT FROM AUTHOR]

This contribution characterises the stratigraphic schemes of the Quaternary as constructed and published by Leszek Lindner in 1967-2019. The oldest schemes assume the subdivision of the Pleistocene into three glaciations (i.e., Cracow, Middle-Polish and Baltic) separated by two interglacials (Great and Eemian). The scheme published in 1992 comprises eight glacial and seven interglacial units. The most recent scheme for the Quaternary contains seven advances of the Scandinavian ice-sheet on the area of Poland during the Nidanian (MIS 22), Sanian 1 (MIS 16), Sanian 2 (MIS 12), Liviecian (MIS 10), Krznanian (MIS 8), Odranian (MIS 6), and Vistulian (MIS 2-5d) glaciations. They are separated by six interglacials: Podlasian, Ferdynandovian, Mazovian, Zbójnian, Lublinian and Eemian. The ranges of glacial transgressions, and key interglacial and preglacial sites are assembled in a cumulative scheme for the area of Poland. We review the main study methods on which the subsequent versions of the stratigraphic scheme were based. These include Prof. Lindner's own detailed field research in glaciated and extraglacial areas, and paleofloristic, paleontological and paleomagnetic studies of major interglacial sites carried out by numerous researchers, as well as thorough literature studies. [ABSTRACT FROM AUTHOR]

The Hengduan Mountains region is a biodiversity hotspot known for its topologically complex, deep valleys and high mountains. While landscape and glacial refugia have been evoked to explain patterns of interspecies divergence, the accumulation of intra‐species (i.e., population level) genetic divergence across the mountain‐valley landscape in this region has received less attention. We used genome‐wide restriction site‐associated DNA sequencing (RADseq) to reveal signatures of Pleistocene glaciation in populations of Thitarodes shambalaensis (Lepidoptera: Hepialidae), the host moth of parasitic Ophiocordyceps sinensis (Hypocreales: Ophiocordycipitaceae) or "caterpillar fungus" endemic to the glacier of eastern Mt. Gongga. We used moraine history along the glacier valleys to model the distribution and environmental barriers to gene flow across populations of T. shambalaensis. We found that moth populations separated by less than 10 km exhibited valley‐based population genetic clustering and isolation‐by‐distance (IBD), while gene flow among populations was best explained by models using information about their distributions at the local last glacial maximum (LGML, 58 kya), not their contemporary distribution. Maximum likelihood lineage history among populations, and among subpopulations as little as 500 m apart, recapitulated glaciation history across the landscape. We also found signals of isolated population expansion following the retreat of LGML glaciers. These results reveal the fine‐scale, long‐term historical influence of landscape and glaciation on the genetic structuring of populations of an endangered and economically important insect species. Similar mechanisms, given enough time and continued isolation, could explain the contribution of glacier refugia to the generation of species diversity among the Hengduan Mountains. [ABSTRACT FROM AUTHOR]

The use of geological–geomorphological and geochronological (14C, OSL) methods allowed establishing that the bordering mountains of the Chuya basin (Russian Altai) were affected by glaciation as early as the Middle Pleistocene, about 160–180 ka (MIS 6). However, the ice-dammed lake with the highest (up to 2100 m a.s.l.) strandlines in the Chuya and Kurai basins existed later than 90–80 ka, i.e., in the Late Pleistocene. This chronological benchmark limits the influence of the catastrophic outburst floods of the largest lakes on the accumulation of the Inya formation in the Chuya and Katun river valleys. It is confirmed that a large ice-dammed lake existed and had a water level of at least 1730 m a.s.l. in MIS 2 in the Kurai basin. The lake drained no later than 16 ka. Synchronously (about 17–16 ka) the accumulation of diluvial–lacustrine cyclites began in the Inya mouth. It was found that the accumulation of the Saldzhar formation in the Katun River valley between the mouths of the Chuya and Sema rivers was long-lasting during the entire MIS 2 not only as a result of flood events, but also due to gradual hydrological processes. It is necessary to revise the concept adopted by SibRISC in 2018. This concept assumes (i) the absence of ice-dammed lakes in intermont basins of Russian Altai in MIS 2 and (ii) the accumulation of the Inya and Saldzhar catafluvial formations, as well as the high and medium terraces they deposited in the valleys of the Chuya and Katun rivers before 90 ka. [ABSTRACT FROM AUTHOR]

Soajo Mountain is located in the northwestern Iberian Peninsula near the border between Portugal and Spain. Its highest elevation is 1416 m at the Pedrada summit. During the Pleistocene, the cascade cirques on the east flank and the icefield that covered the flattened surface of the high plateau generated several glacier valleys. This study presents a paleoglacial reconstruction of the relict glacial landscape in Soajo Mountain for the Glacial Maximum Extent (GME) through the following methods: (1) a detailed geomorphological map supported by high-resolution orthophotography, digital elevation models with a spatial resolution of 70 cm, and field surveys; (2) the delineation of the glacial surface, and the calculation of the glacial flowlines to obtain the numerical model of the ice thickness; and (3) an estimation of the paleoELA altitudes. The paleoglacial reconstruction, using GlaRe methodology, reveals a glacial surface of 16 km2, including an icefield on the Lamas de Vez plateau (mean elevation of 1150 m) and a radial glacial flow to the east and north. The arrangement of the glaciated area attests to the topographic, lithological, and structural conditioning on the development of small glacial tongues, with an emphasis on the ice tongue flowing northwards, with a thickness of 173 m and a length of 2.92 km. The Soajo GME paleoglacier comprises three main glacial sectors: Lamas de Vez Icefield, Vez and Aveleira Valleys, and the Eastern Glacial Sector. These paleoglaciers have achieved maximum ice volumes of 214.4 hm3, 269.2 hm3, and 115.8 hm3, respectively, with maximum ice thicknesses of 127 m, 173 m, and 118 m, respectively. On the west flank, a smaller paleoglacier named Branda da Gémea recorded an ice volume of 24.3 hm3 and a maximum ice thickness of 110 m. According to the ELA-AABR method, Soajo Mountain has one of the lowest ELA values in the Iberian NW, ranging from 1085 to 1057 m. This is due to its oceanic location, an orographic barrier effect, and the influence of the polar front. [ABSTRACT FROM AUTHOR]

This work describes the Mousterian lithic artifacts found in the Avetrana karst filling (Apulia), among the oldest of southern Italy. A volcanoclastic layer found at the base of Bed 8, in the highest part of the stratigraphic succession, is also described. The compositional characteristics of the glasses of this volcanoclastic layer indicate a possible area of origin in the Mount Vulture volcano, and allow us to suggest that it is an aeolian fallout that occurred during or immediately after a late eruption of the Mount Vulture, probably within the 132 ± 10 ka time span. The chronological result relating to the volcanoclastic sediments would place the underlying beds in the last Interglacial, MIS 5e, and the overlying Bed 8 at the onset of last Glacial period, MIS 5d. Moreover, it is in agreement with the paleoclimatic considerations based on the ecological and biogeographical features of mammal assemblages and it has a very important significance also for the biochronology of the Pleistocene. In fact, it allows us to confirm that some taxa found in the Avetrana succession, such as Crocidura gr. suaveolens , Arvicola italicus , the evolved form of Microtus (Terricola) gr. savii , and the modern form of Dama dama , occur for first time in Italy at the beginning of Late Pleistocene. [ABSTRACT FROM AUTHOR]

Insect speciation is among the most fascinating topics in evolutionary biology; however, its underlying mechanisms remain unclear. Allopatric speciation represents one of the major types of speciation and is believed to have frequently occurred during glaciation periods, when climatic oscillation may have caused suitable habitats to be fragmented repeatedly, creating geographical isolation among populations. However, supporting evidence for allopatric speciation of insects in East Asia during the Pleistocene glaciation remains lacking. We aim to investigate the effect of climatic oscillation during the Pleistocene glaciation on the diversification pattern and evolutionary history of hemipteran insects and to test the hypothesis of Pleistocene species stability using spinous assassin bugs Sclomina (Hemiptera: Reduviidae), a small genus widely distributed in southern China but was later found to have cryptic species diversity. Here, using the whole mitochondrial genome (mitogenome) and nuclear ribosomal RNA genes, we investigated both interspecific and intraspecific diversification patterns of spinous assassin bugs. Approximate Bayesian computation, ecological niche modeling, and demographic history analyses were also applied to understand the diversification process and driven factors. Our data suggest that the five species of Sclomina are highly diverged, despite three of them currently being cryptic. Speciation occurred during the Pleistocene when suitable distribution areas were possibly fragmented. Six phylogeographic groups in the type species S. erinacea were identified, among which two groups underwent expansion during the early Last Glacial Period and after Last Glacier Maximum. Our analyses suggest that this genus may have experienced climate‐driven habitat fragmentation and postglacial expansion in the Pleistocene, promoting allopatric speciation and intraspecific diversification. Our results reveal underestimated species diversity in a small insect group and illustrate a remarkable example of allopatric speciation of insects in East Asia promoted by Pleistocene climatic oscillations. These findings provide important insights into the speciation processes and aid the conservation of insect species diversity. [ABSTRACT FROM AUTHOR]

The Tibetan Plateau is an important area for studying global climate change, but the answers to many scientific problems remain unknown. Here, we present new information from the lacustrine sedimentary record in the western Tibetan Plateau, related to the third most‐recent glaciations. Continuous sediment data, including sporopollen, particle size, total organic carbon, mass susceptibility, CaCO3, CaSO4, BaSO4 contents and chronological data, were reconstructed and revealed that climate and environmental conditions obviously and distinctly changed between 600 and 700 thousand years ago. In comparison, the data obtained from the Guliya ice core in this area also corresponds to the global glacial climatic characteristics recorded in basin sediments in the eastern and southeastern regions of the plateau and to the information obtained from ice cores in the Antarctic and Arctic regions. In this study, we conclude that the main reason for the glaciations and new tectonic movement must be a geomagnetic polarity reversal 774 thousand years ago (from Matuyama to Brunhes). Indeed, the results of this study suggest that the described reversal event might have influenced the current global climate pattern and will continue to impact climatic changes in the future. [ABSTRACT FROM AUTHOR]

Simple Summary: Italy plays a central role in the research on Europe's biogeography because of its position in the middle of the Mediterranean, which is a global hotspot of diversity. This study investigated how present patterns of earwig species richness and composition in Italy are affected by climatic, geographical, and historical factors. Earwig richness does not decrease from the base to the tip of the Italian peninsula, which contrasts with the so-called 'peninsula effect'. However, richness does not increase southward either, suggesting that southern regions did not play a crucial role as a refuge during Pleistocene glaciations. Inter-regional similarities in species composition between regions is more influenced by their geographical proximity than climatic similarity, although richness is positively correlated with precipitation, in accordance with earwig preferences for humid conditions. The similarity in species composition with central European fauna decreases southward, indicating possible exchanges between central Europe and Italy. The majority of the earwigs of the Italian fauna are either widespread across Europe and the Palearctic, or confined to the main Italian mountain ranges, that is, the Alps and the Apennines. The isolation of ancient earwig populations on mountains resulted in the development of a high proportion of endemics, making the Italian earwig fauna one of the richest in Europe. Placed in the center of the Mediterranean biodiversity hotspot, Italy plays a central role for the study of Europe's biogeography. In this paper, the influence of climatic, spatial, and historical factors on current patterns of variation in earwig species richness and composition is investigated. The Italian earwig fauna is mainly composed of species which are either widely distributed in Europe and the Palearctic region or that are endemic to the Alps and the Apennines. Variation in species richness does not follow any obvious geographical patterns, but a positive influence of precipitation on richness is consistent with earwig preferences for humid climates. European mainland territories did not contribute substantially to the current biodiversity of Italian earwigs, which explains the lack of a distinct peninsula effect, although a southward decrease in similarity with the central European fauna was observed. However, southern areas did not exert a pivotal role during Pleistocene glaciations in determining current patterns of species richness. Variation in species composition among Italian regions can be mostly explained by geographical proximity, while climatic differences and historical (paleogeographical and paleoecological) events seem to have played a minor role. However, the isolation of ancient earwig stocks on Italian mountains led to the origin of a relatively large number of endemics, which makes the Italian earwig fauna one of the richest in Europe. [ABSTRACT FROM AUTHOR]

On the basis of data collected since 1961, the authors of the current article conducted an analysis of the distribution of Uropodina (Acari: Mesostigmata) species in Poland. The areas of occurrence of the species were compared with the range boundaries of the successive Pleistocene glaciations in Poland. The second aim of the study was to establish the importance of the former nunataks (paleonunataks) for the preservation of biodiversity of this group of mites in Poland. The study has revealed that there are six types of distribution of Uropodina species in the area of Poland: (i) species distributed consistently in the whole area of the country, (ii) species having their northern range of occurrence in Poland, (iii) species having their north-western range of occurrence, (iv) species having their north-eastern range of occurrence, (v) species of boreal-mountainous distribution with evident disjunction in central Poland, and (vi) Carpathian species migrating northwards along the Vistula River. The analyses of the species composition of Uropodina communities on nunataks shows that the concave nunatak in Jura Krakowsko-Czestochowska, described in the literature as the "Jurassic Inland Oasis", turned out to be the location with the highest Uropodina diversity, whereas on the nunatak of the Ślęża Massif, which was covered by two glaciations, the Uropodina diversity was the lowest. [ABSTRACT FROM AUTHOR]

Oxygen is essential for marine ecosystems, and it is linked by respiration to carbon storage in the deep ocean. Reconstructing oxygen concentrations in the past has been limited by the absence of quantitative, rather than qualitative, proxies, but several new (semi-) quantitative oxygen proxies have recently been developed. In this study we explore the possibility of adding bulk sedimentary uranium (U) to this list by normalizing it to barium (Ba). First, U/Ba and bottom water oxygen concentrations are compared on a global scale, using a core top database, in pelagic environments greater than 200 m water depth. Then, the relationships between U/Ba and bottom water oxygen are examined on smaller spatial scales: within each ocean basin and regionally within the Eastern Equatorial Pacific, the Arabian Sea, and Western Equatorial Atlantic. At this regional scale, where secondary influences on the behavior of both U and Ba may be more spatially uniform, empirical piecewise linear calibrations are developed and subsequently tested on downcore records. U/Ba-based oxygen reconstructions generally agree with those derived from previously published alkenone preservation and benthic foraminiferal surface porosity records. Several limitations to the utility of U/Ba as a proxy for oxygen have also been identified. The proxy should only be applied in the uppermost sedimentary intervals that contain porewater sulfate to minimize barite diagenesis, and phosphorus contents should be monitored for the potential influence of apatite on uranium content. U/Ba is more successful at recording oxygen concentrations during mean glacial and interglacial periods than during climate transitions, when the timing and amplitude may be more sensitive to burndown and smoothing. Conservative errors on the calibrations result in the greatest utility of U/Ba in regions with relatively high oxygen concentrations (e.g., >50 μmol/kg) and large oxygen variability (±10 s of μmol/kg). Even with these caveats, U/Ba is only one of two quantitative oxygen proxies potentially capable of recording variability above 50 μmol/kg, and further investigation into its functionality in different environmental settings is worthwhile in the endeavor to reconstruct the full marine range of oxygen concentrations in the past. [ABSTRACT FROM AUTHOR]

Glaciation has been a powerful determiner of species distributions and the genetic structure of populations. Contemporary distributions of many organisms in North America's Western Cordillera reflect the influence of Pleistocene glaciation. We identified a pattern of north–south differentiation in the genus Prosimulium of western North America, which reflects the separation of northern and southern populations by the North American Ice Sheet during the Pleistocene Epoch. The taxonomic implication is that new species exist within nominal species, requiring formal description or revalidation of names currently in synonymy. We morphologically and cytogenetically examined populations of one nominal species of black fly, Prosimulium esselbaughi Sommerman, over its known range from Alaska south to California and Colorado. Chromosomal and morphological evidence supports the presence of two species, P. esselbaughi sensu stricto from Alaska to at least southern British Columbia, and a new species, Prosimulium supernum in the central Rocky Mountains and high Sierra Nevada range of the United States. The new species is described in all life stages above the egg, along with its polytene chromosomes. The existence of differentiated populations of other nominal species of black flies in northern and southern North America provides a system for investigating possible co-differentiation of vectors and parasites. [ABSTRACT FROM AUTHOR]

To study the morphological characteristics of the largest canyons in the Southern and Central Basins of Lake Baikal, we analysed a digital relief model based on high-resolution multibeam bathymetric surveying. We evaluate the role of tectonic, lithological and climatic controlling factors in the formation and evolution of canyons. Tectonic activity and seismicity act as a catalyst for canyon formation and for the development of sublacustrine gravity flows and turbidity currents, and alter the morphological appearance of already existing canyons. The influence of tectonics on the formation of the Baikal canyons is particularly noticeable on the western slope of Lake Baikal, where canyons are mainly located along faults and follow their directions. Gravity flows and turbidity currents become more important during earthquakes and periods of lower lake level. When canyon heads are located close to river mouths, riverine processes have a significant impact on the evolution of the canyon. The topography of the original surface and the lithology of the substrate also play a significant role in the evolution of canyons and in shaping the canyon morphology. During periods of lower lake level (during Pleistocene glacial periods) riverine processes were responsible for initiating the formation of many canyons in Lake Baikal. The canyons developed under the complex influence of the factors considered. One or another factor could be dominant at different stages of their evolution, while the role of the other factors became secondary. These roles could interchange over time. The Baikal canyons show a great deal of resemblance to canyons in marine environments, in terms of morphological characteristics as well as of canyon-forming processes. We propose a morphogenetic classification of the underwater valleys and canyons of Lake Baikal. [ABSTRACT FROM AUTHOR]

The highest parts of the European mountain massifs are covered by subalpine and alpine vegetation, with rich flora containing many relic woody plants adapted to cold temperatures and relatively short vegetation periods. In the Ukrainian Carpathians, only several highest mountain massifs form environmental conditions suitable for high mountain plants. The aim of the study was the detection of the centre of biodiversity of the high mountain plants in the East Carpathians in Ukraine. We expected the largest number of high mountain woody species in the Ukrainian East Carpathians would occur in the Chornohora, the largest and most elevated mountain chain in the country. To solve this problem, the geographic distribution of 16 woody species was analysed cartographically. We gathered georeferenced data of 919 localities of taxa, which occur in the subalpine and alpine vegetation belts, and prepared maps of their distribution using QGIS software. Additionally, we analysed vertical distribution and occurrence on different expositions of every taxon. Most of analysed subalpine and alpine species occur in the highest and the largest mountain massifs. The high mountain woody species occur in the Ukrainian parts of the East Carpathians mainly in the largest mountain massifs, the Chornohora, Svydovets, Chyvchyny, Marmarosh, and to a lesser extent, also in the Gorgany. The vertical distribution and predominant occurrence on the northern or close to northern expositions of most subalpine and alpine species indicate their demands for the relatively high level of humidity of the soil and high level of precipitation. These condition point to the relic character of most of analysed species, which origin from the glacial periods of the Pleistocene. Most of the taxa, which have centres of their distribution in the alpine and sub-alpine vegetation belts of the East Carpathians in the Ukraine territory are valuable but threatened elements of the Ukrainian flora. [ABSTRACT FROM AUTHOR]

High-resolution seismic data of the Ramasetu region revealed three subaerial unconformities S1, S2, and S3. S1 is the youngest subaerial unconformity, whereas S3 is the oldest. These subaerial unconformities have been determined based on the presence of channel-incision signatures. Identified buried channels originated in the Palk Strait and debouched in the Gulf of Mannar. Youngest buried channels became most active during MIS 3 (~60-29 ka) and were buried entirely at ~7.0 ka. The study suggests that the Palk Strait evolved as a large multicentered freshwater reservoir during the last glacial period and remained a freshwater reservoir until seawater started encroaching the region at ~8.5 ka. The Ramasetu region was a potential habitat zone for foragers, with fresh and saline water ecosystems available at opposite banks. During the Microlithic and terminal Pleistocene, Homo sapiens needed to cross high-energy rivers using floaters/rafts in wet seasons of MIS 2 and 3. At the same time, they used a direct walkable land link in the extreme dry season of MIS 2. During the early to mid-Holocene, foragers required floaters/rafts or artificial structures (such as bandh/bridge) to cross shallow, low-energy estuarine patches of the Ramasetu. The Palk Strait region was not crossable without using boats/ships in the last ~7 ka except during minor sea-level falls. [ABSTRACT FROM AUTHOR]

Pleistocene permafrost has been recognized in the lowlands of extra-Andean Argentina from Tierra del Fuego to the Rio Negro valley at 40°S, and to the Sierras Australes at 38°S. Features that could have formed only by cryogenic activity at elevations between 230-400 m above sea level in surficial deposits and in the bedrock beneath are described here as far north as 36°S. These features are not as pronounced as they are farther south because most of central Argentina was a cold desert during the glacial episodes, and therefore little ice formed. Calcareous dust, formerly considered as pedogenic and now known to be glaciogenic, is closely associated with these features. Secondary precipitates, such as lamellar crystals of calcite and gypsum, and other microscopic features like those observed in perpetually frozen ground also confirm that this region experienced permafrost at some time. These new findings mean that the area affected by periglaciation is much larger than previously thought and expanded more than 200 km farther to the north. Stratigraphic evidence and geomorphological features place both deposits and cryogenic features within them as early-middle Pleistocene age. [ABSTRACT FROM AUTHOR]

We detected five divergent COI lineages in Priapulus caudatus Lamarck, 1816: four from the Arctic and one from the Sea of Okhotsk. K2P distances ranged from 6.87% to 14.35% with a mean distance of 10.03%, which typically corresponds to inter-species distances. However, four of five lineages (excluding the Okhotsk one) were found in syntopy, and no morphological differences between potential species were found. Single-gene phylogenies for the mitochondrial 16S, as well as nuclear 28S, 18S, and FoxQ2 markers, had different topologies and were non-congruent with the COI tree. This may point to an incomplete speciation due to a series of long-time geographical isolations during Pleistocene glaciations in different parts of range of P. caudatus. The 28S and 18S sequences fell into two genotypes, one being found mainly in the intertidal, and the other exclusively in the subtidal, which indicates the prevalence of unidirectional migrations from the intertidal into the subtidal. Because Arctic intertidal populations disappear during glaciations and recover in interglacial periods, and due to their partial reproductive isolation from each other, they give rise to new genetic lineages. Subtidal populations are permanent and have less significant isolation boundaries, therefore they accumulate genetic diversity. [ABSTRACT FROM AUTHOR]

Understanding how climatic and environmental changes, as well as human activities, induce changes in the distribution and population size of avian species refines our ability to predict future impacts on threatened species. Using multilocus genetic data, we show that the population of a threatened New Zealand endemic open‐habitat specialist, the Black‐fronted Tern Chlidonias albostriatus – in contrast to forest specialists – expanded during the last glacial period. The population has decreased subsequently despite the availability of extensive open habitat after human arrival to New Zealand. We conclude that population changes for open habitat specialists such as Black‐fronted Terns in pre‐human New Zealand were habitat‐dependent, similar to Northern Hemisphere cold‐adapted species, whereas post‐human settlement populations were constrained by predators independent of habitat availability, similar to other island endemic species. [ABSTRACT FROM AUTHOR]

The Late Pleistocene Jupania palaeoglacier (area 0.85 km2, 1.7 km long) was reconstructed in the headwaters of the Ceremuşul Alb/Bilyj Cheremosh valley (Maramureş Mountains). The study area represents one of the most inaccessible natural areas in the Romanian part of the Eastern Carpathians where the legacy of the Pleistocene glaciation has recently been discovered. Based on mapping of glacial landforms and deposits, we reconstruct glacier dimension and ice-surface geometry, as well as estimate equilibrium line altitude (ELA) during the maximal ice extent (MIE). Well-preserved terminal moraines mark the extent of glacier front at ~1400 m a.s.l. Sedimentological analysis documents that the lateral moraines are sometimes overbuilt by 1-1.5 m thick colluvial deposits. The ELA for the Jupania palaeoglacier calculated with the Area-Altitude-Balance-Ratio (AABR) 1.6 was 1630 m. However, the gentle-sloping mountain-top could serve as an important snow contribution area to glacier mass balance; therefore, the ELA could potentially exist even higher at 1676 m. The resulting climatic ELA (1630-1676 m) in the south-eastern part of the Maramureş Mountains fits well with the rising trend of ELA towards the southeast observed between Chornohora (ELA = 1516 m) and Rodna Mountains (ELA = 1697 m). The SE rising trend of the ELA corresponds well with the dominant palaeowind direction suggested in the Carpathian region and supports the prevalence of zonal circulation pattern in Central Eastern Europe during the culumination of the last glaciation. [ABSTRACT FROM AUTHOR]

This paper describes the course of migration and expansion of small mammals in the Makalu Barun region influenced by the orogenetic uplift of the East Nepal Himalaya and climatically conditioned changes in the extent of morphogenetic zones from the Upper Pleistocene up to the present. The results of zoological and parasitological research are compounded with the knowledge of the dynamic development of landforms, which testifies to significant changes in the high-mountain environment during the Quaternary. The migration of Palearctic species of small mammals across the gradually emerging orographical barrier during the orogenesis of the High Himalaya was completely interrupted by the glaciation in the Upper Pleistocene. This extensive glaciation also excluded occurrence and survival of small mammals in the high-mountain valleys of the Makalu Barun region. Migration routes and the extension of the territory of small mammals remained open only in the periglacial zone of the Arun and Barun Khola valleys. Following the interstadial period of warmer and humid climate conditions were changed by the Late Glacial Maximum when small mammals were again pushed away from heavily glaciated valleys to the lower altitude periglacial zone. During the Holocene interglacial, the occurrence of fauna and flora in the high-mountain valleys depended on repeated spatial changes of periglacial and glacial morphoclimatic zones. Current biogeographical hazards are accentuated due to the rapid retreat of glaciers, the expansion of the periglacial morphoclimatic zone and the increased human impact in the High Himalaya. [ABSTRACT FROM AUTHOR]

The South American temperate forests were subjected to drastic topographic and climatic changes during the Pliocene‐Pleistocene as a consequence of the Andean orogeny and glacial cycles. Such changes are common drivers of genetic structure and adaptation. Embothrium coccineum (Proteaceae) is an emblematic tree of the South American temperate forest (around 20°S of latitude) that has strongly been affected by topographic and climatic events. Previous studies have shown a marked genetic structure in this species, and distinct ecotypes have been described. Yet, little is known about their adaptive genetic responses. The main goal of this study was to investigate the effects of historical and contemporary landscape features affecting the genetic diversity and connectivity of E. coccineum throughout its current natural distribution. Using over 2000 single nucleotide polymorphisms (SNPs), we identified two genetic groups (a Northern and a Central‐Southern group) that diverged around 2.8 million years ago. The level of genetic structure was higher among populations within the Northern genetic group than within the Central‐Southern group. We propose that these differences in genetic structure may be due to differences in the assemblages of pollinators and in the evolutionary histories of the two genetic groups. Moreover, the data displayed a strong pattern of isolation by the environment in E. coccineum, suggesting that selection could have led to adaptive divergence among localities. We propose that in the Chilean temperate forest, the patterns of genetic variation in E. coccineum reflect both a Quaternary phylogenetic imprint and signatures of selection as a consequence of a strong environmental gradient. [ABSTRACT FROM AUTHOR]

Soft-sediment deformation structures have been identified in glaciolacustrine deposits of the terrace complexes of Imandra Lake (Kola Region, northeastern part of the Fennoscandian Shield). According to the paleoseismological criteria, we found that these deformation structures were induced by strong earthquakes. These earthquakes led to the occurrence of secondary deformations of various morphology and sizes in the sandy sediments, forming a single complex consisting of intensely deformed and destructed deposits and associated clastic dikes and cracks. Among the plastic deformations, the phenomena of liquefaction, boudinage structures, flame structures, irregular convolute stratifications, diapir-like structures and synsedimentary folds are developed. Cracks, micro-fractures, and dykes predominate among brittle deformations. The spatial and stratigraphic distributions of soft-sediment deformation structures were used to infer about the activation of faults during the Late Glacial and Postglacial period of the sublatitudinal and northwestern strike directions that limit the different-scale blocks of the Earth's crust. According to radiocarbon analysis data and paleogeographic reconstructions, the formation of soft-sediment deformations took place at the end of the Younger Dryas and the beginning of the Preboreal period between 12 900–11 500 cal. a BP, and later, in the Preboreal period and beginning of the Boreal period between 11 500–9900 cal. a BP. It was this period that was accompanied by increased seismic activity not only in the Kola region, but also in the whole of Fennoscandia. [ABSTRACT FROM AUTHOR]

Late Early Pleistocene vertebrate assemblages in the Mediterranean area have sparked the interest of the scientific community in the last two decades mainly thanks to the discovery of fossils and/or stone tools testifying to the presence of early Homo. However, our knowledge of most of these assemblages is biased by the lack of well-constrained chronological data, especially for those close to or related to the Jaramillo magnetostratigraphic subchron (ca. 1.0 Ma). As a matter of fact, the available European palaeontological assemblages chronologically close to the Jaramillo interval are overall scarce, especially for the period prior to the so-called '0.9 Ma event'. This long and cold glacial period was characterised by profound changes in ecosystems and important faunal turnover in Europe, including the replacement of most Villafranchian species by typical Galerian ones. Here, we report on the carnivoran remains from Collecurti (central Italy), that is, one of the few available Jaramillo-dated assemblages in Europe. The Collecurti sample includes the species Canis (Xenocyon) lycaonoides, Canis mosbachensis, and Ursus deningeri and is here described in detail for the first time and compared with those from similar-aged European sites. [ABSTRACT FROM AUTHOR]

The Quaternary was the main evaporite deposition period in the Qaidam Basin (QB), but the correlation between the evaporite deposition period and the glacial period is still unclear. In this study, the research objects are primarily evaporite‐bearing strata in a 461.58 m‐long drill core in the QB. X‐ray powder diffraction (XRD) and scanning electron microscopy (SEM) were applied to study the evaporite minerals, U‐Th dating being applied to construct the 230Th geochronological framework. Evaporite deposition from Marine Isotope Stage (MIS) 15 to MIS 4 in the borehole was reconstructed via mineralogical and geochronological data. The evaporite minerals are mainly halite (NaCl), mirabilite (Na2SO4·10H2O), thenardite (Na2SO4) and gypsum (CaSO4·2H2O). A total of 9 effective 230Th data points, ranging from 492.5 ± 43.0 ka to 62.0 ± 11.9 ka, were obtained. The depositional age of the earliest halite layer in the borehole is 592.5–563.0 ka. There were mirabilite deposits in the QB during the cold glacial environment of MIS 6. During MIS 4, the study area desiccated, with mirabilite and halite being deposited. This study suggests that mirabilite is an indicator mineral for the glacial environment in the QB, while halite deposition does not correspond well to glaciation. [ABSTRACT FROM AUTHOR]

[Display omitted] • The biogeographic dispersal has affected current local species richness of sky islands in the Himalaya-Hengduan Mountains. • Gaultheria ser. Trichophyllae mostly evolved toward higher longitudes (eastward), with the eastward intra-regional dispersals and westward inter-regional dispersals frequently occurred. • Frequent eastward intra-regional dispersals may be facilitated by paleo-drainages reorganization and monsoon intensification. • The dispersal time and distance, rather than frequency significantly influence the pattern of species richness of Gaultheria ser. Trichophyllae. In addition to topography and climate, biogeographic dispersal has been considered to influence plant diversity in the Himalaya-Hengduan Mountains (HHM), yet, the mode and tempo of sky island dispersal and its influence on species richness has been little explored. Through phylogenetic analysis of Gaultheria ser. Trichophyllae , a sky island alpine clade within the HHM, we test the hypothesis that dispersal has affected current local species richness. We inferred the dynamics of biogeographic dispersal with correlation tests on direction, distance, occurrence time, and regional species richness. We found that G. ser. Trichophyllae originated at the end of the Miocene and mostly dispersed toward higher longitudes (eastward). In particular, shorter intra-regional eastward dispersals and longer inter-regional westward dispersals were most frequently observed. We detected a prevalence of eastward intra-region dispersals in both glacial periods and interglacials. These dispersals may have been facilitated by the reorganization of paleo-drainages and monsoon intensification through time. We suggest that the timing of dispersal corresponding to glacial periods and the prevalence of intra-region dispersal, rather than dispersal frequency, most influenced the pattern of species richness of G. ser. Trichophyllae. This study facilitates a more comprehensive understanding of biodiversity in the sky islands within the HHM. [ABSTRACT FROM AUTHOR]

Montane systems provide excellent opportunities to study the rapid radiation influenced by geological and climatic processes. We assessed the role of Pleistocene climatic oscillations and mountain building on the evolution history of Triplophysa robusta, a cold-adapted species restricted to high elevations in China. We found seven differentiated sublineages of T. robusta, which were established during the Mid Pleistocene 0.87-0.61 Mya. The species distribution modeling (SDM) showed an expansion of T. robusta during the Last Glacial Maximum (LGM) and a considerable retraction during the Last Interglacial (LIG). The deep divergence between Clade I distributed in Qinling Mountains and Clade II in Northeastern Qinghai-Tibet Plateau (QTP) was mainly the result of a vicariance event caused by the rapid uplifting of Qinling Mountains during the Early Pleistocene. While the middling to high level of historical gene flow among different sublineages could be attributed to the dispersal events connected to the repetition of the glacial period during the Pleistocene. Our findings suggested that frequent range expansions and regressions due to Pleistocene glaciers likely have been crucial for driving the phylogeographic pattern of T. robusta. Finally, we urge a burning question in future conservation projection on the vulnerable cold-adapted species endemic to high elevations, as they would be negatively impacted by the recent rapid climate warming. [ABSTRACT FROM AUTHOR]