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The emergence of the Middle Palaeolithic, and its variability over time and space are key questions in the field of prehistoric archaeology. Many sites have been documented in the south-eastern margins of the Massif central and the middle Rhône valley, a migration path that connects Northern Europe with the Mediterranean. Well-dated, long stratigraphic sequences are essential to understand Neanderthals dynamics and demise, and potential interactions with Homo sapiens in the area, such as the one displayed at the Maras rock shelter ("Abri du Maras"). The site is characterised by exceptional preservation of archaeological remains, including bones dated using radiocarbon (14C) and teeth using electron spin resonance combined with uranium series (ESR/U-series). Optically stimulated luminescence was used to date the sedimentary deposits. By combining the new ages with previous ones using Bayesian modelling, we are able to clarify the occupation time over a period spanning 200,000 years. Between ca. 250 and 40 ka, the site has been used as a long-term residence by Neanderthals, specifically during three interglacial periods: first during marine isotopic stage (MIS) 7, between 247 ± 34 and 223 ± 33 ka, and then recurrently during MIS 5 (between 127 ± 17 and 90 ± 9 ka) and MIS 3 (up to 39,280 cal BP). [ABSTRACT FROM AUTHOR]

We investigate the position and intensity changes of the Intertropical Convergence Zone (ITCZ) over Asia (50°E−135°E) relative to the preindustrial period annually and seasonally during the Last Interglacial (LIG), Last Glacial Maximum (LGM), and mid‐Holocene (MH) using available models from phases 3 and 4 of the Paleoclimate Modeling Intercomparison Project. The multi‐model mean shows that the June–July–August ITCZ variations generally dominate the annual changes. The Asian ITCZ shifts northward over western Asia and southward over the eastern side in both the LIG and MH, and the opposite occurs in the LGM. Its intensity varies with longitude similarly for the LIG and MH and generally weakens in the LGM. Precipitation changes associated directly with ITCZ indices are primarily caused by the dynamic term in the LIG and MH, while both dynamic and thermodynamic terms play roles in the LGM, with major contributions from the convergence components. Plain Language Summary: As an intense rain belt, the Intertropical Convergence Zone (ITCZ) has an important influence on the regional climate, particularly over Asia. However, its future and past behaviors remain unclear. Based on multi‐model experiments, we investigate Asian ITCZ changes in location and intensity during the past three typical periods: the interglacial periods of the Last Interglacial and the mid‐Holocene and the glacial period of the Last Glacial Maximum. The Asian ITCZ overall strengthens and regionally moves northward over the western part and southward over the eastern part during the two interglacial periods relative to its preindustrial state, which are generally opposite to the position and intensity changes in the glacial period. These ITCZ changes are directly caused by uneven precipitation changes, which are dominated by atmospheric circulation changes during interglacial periods and additionally contributed from water vapor content changes during glacial periods, primarily through the vertical motion of air. Key Points: Asian Intertropical Convergence Zone (ITCZ) shifts northward over western Asia and southward over the eastern side in Last Interglacial (LIG) and mid‐Holocene (MH), and the opposite occurs in Last Glacial Maximum (LGM)Asian ITCZ intensity varies with longitude similarly for LIG and MH, while it weakens during LGMDynamic term dominates the ITCZ‐related precipitation changes in LIG and MH, while both dynamic and thermodynamic terms play roles in LGM [ABSTRACT FROM AUTHOR]

This paper explores the resizing, reshaping and connectivity of islands by examining ongoing relations between land and sea in the context of the Channel Island of Guernsey. Ideas of materiality, temporality and vertical depth are employed to explore how contemporary tides and past sea‐level change impact island–island connections, and island–mainland connections between Guernsey and France. By focusing on the littoral zone as a space of encounter between land and sea, the paper explores some of the processes that challenge the notion of an island having fixed edges, emphasising the island's shape and size as always in flux. The paper then explores how tides alternatively reveal and hide material structures such as rocks and causeways, making the underwater scape temporally visible and differently accessible as an extension of land. It enables connections to be made and remade. This is demonstrated through the example of Guernsey and the tidal island of Lihou. The paper subsequently considers these ideas in the context of Quaternary sea‐level change. The land known as Guernsey alternated between literal island surrounded by water, and a steep‐sided plateau on the Normanno‐Breton plain, coinciding with interglacials and glacials. This connection is referred to as geologic. I argue that by acknowledging Guernsey's former visible connection with France, lack of contemporary visibility in the underwater scape does not render this a disconnection. Rather, the geologic, as further evidenced in the contemporary natural and built environment of Guernsey, continues through an underwater scape. It reappears in other Channal Islands and France, demonstrating ongoing connections at a land–sea–geologic interface. The paper argues for geology as a form of vertical depth. It calls for greater consideration of the geologic in the human geographical study of islands. [ABSTRACT FROM AUTHOR]

Pliocene global temperatures periodically exceeded modern levels, offering insights into ice sheet sensitivity to warm climates. Ice-proximal geologic records from this period provide crucial but limited glimpses of Antarctic Ice Sheet behavior. We use an ice sheet model driven by climate model snapshots to simulate transient glacial cyclicity from 4.5 to 2.6 Ma, providing spatial and temporal context for geologic records. By evaluating model simulations against a comprehensive synthesis of geologic data, we translate the intermittent geologic record into a continuous reconstruction of Antarctic sea level contributions, revealing a dynamic ice sheet that contributed up to 25 m of glacial-interglacial sea level change. Model grounding line behavior across all major Antarctic catchments exhibits an extended period of receded ice during the mid-Pliocene, coincident with proximal geologic data around Antarctica but earlier than peak warmth in the Northern Hemisphere. Marine ice sheet collapse is triggered with 1.5 °C model subsurface ocean warming. Geologically validated ice-sheet model reconstructions show large-scale fluctuations between glacial and interglacial periods, suggesting that the Antarctic Ice Sheet is highly sensitive to past and future warm conditions. [ABSTRACT FROM AUTHOR]

Two major glaciations have been identified on land in England during the Middle Pleistocene. The earliest occurred during the Anglian Stage (= Elsterian, c. Marine Isotope Stage, MIS 12), evidence for which is best developed in lowland Britain, as well as offshore in the southern North Sea and Irish Sea basins. The second took place during the late Middle Pleistocene, with the most compelling evidence found in the West Midlands, intermediate between the Hoxnian (= Holsteinian; broadly MIS 11) and Ipswichian (= Eemian; broadly MIS 5e) interglacial stages during the Late Wolstonian Substage. Until recently this younger glacial episode was less clearly represented in the Pleistocene record and, as a result, had been little studied and weakly defined. Interpreted as the Moreton Stadial glaciation during the Late Wolstonian Substage (= Late Saalian Substage/Drenthe Stadial, c. MIS 6), it was originally recognized in the English Midlands, subsequently being identified in Yorkshire, Lincolnshire and northern East Anglia, and potentially further SW as far as the Bristol Channel. Mapping, in particular by members of the British Geological Survey, however, resulted in the Wolstonian Stage glacial deposits being thought to pre‐date the stage. This was particularly so in East Anglia where there was considerable controversy concerning the number and relationships of glacial sequences, during the 1970–1980s. Yet to the west of East Anglia there remained unequivocal evidence for glaciation during the stage, particularly in Fenland and the eastern English Midlands. Recent radiometric dating across lowland Britain on glacial sediments long thought to belong to a glaciation event in the Wolstonian Stage have now placed a geochronological control on the established regional stratigraphy and confirmed that glaciation occurred in two phases between 199 and 147 ka during the Late Wolstonian Substage. The glacial events of the British Middle Pleistocene can clearly be correlated with the European continent. [ABSTRACT FROM AUTHOR]

The site of LuneryRosieres la-Terre-des-Sablons (Lunery, Cher, France) comprises early evidence of human occupation in mid-latitudes in Western Europe. It demonstrates hominin presence in the Loire River Basin during the Early Pleistocene at the transition between an interglacial stage and the beginning of the following glacial stage. Three archaeological levels sandwiched and associated with two diamicton levels deposited on the downcutting river floor indicate repeated temporary occupations. Lithic material yields evidence of simple and more complex core technologies on local Jurassic siliceous rocks and Oligocene millstone. Hominins availed of natural stone morphologies to produce flakes with limited preparation. Some cores show centripetal management and a partially prepared striking platform. The mean ESR age of 1175 ka ± 98 ka obtained on fluvial sediments overlying the archaeological levels could correspond to the transition between marine isotopic stages (MIS) 37 and 36, during the normal Cobb Mountain subchron, and in particular at the beginning of MIS 36. The Lunery site shows that hominins were capable of adapting to early glacial environmental conditions and adopting appropriate strategies for settling in mid-latitude zones. These areas cannot be considered as inhospitable at that time as Lunery lies at some distance from the forming ice cap. [ABSTRACT FROM AUTHOR]

Exploring the changing process of the geographical distribution pattern of Tetracentron sinense Oliv. and its main influencing factors since the last interglacial period can provide a scientific basis for the effective protection and management of the species. The MaxEnt model was used to construct the potential distribution areas of T. sinense in different periods such as the last interglacial (LIG), the last glacial maximum (LGM), the mid‐Holocene (MID), and the current and future (2050s and 2070s). On the premise of discussing the influence of dominant environmental factors on its distribution model, the suitable area changes of T. sinense under different ecological climate situations were quantitatively analyzed. (1) The AUC and TSS values predicted by the optimized model were 0.959 and 0.835, respectively, indicating a good predictive effect by the MaxEnt model; the potential suitable areas for T. sinense in the current period are mainly located in Southwest China, which are wider compared to the actual habitats. (2) Jackknife testing showed that the lowest temperature in the coldest month (Bio6), elevation (Elev), seasonal variation coefficient of temperature (Bio4), and surface calcium carbonate content (T‐CACO3) are the dominant environmental factors affecting the distribution of T. sinense. (3) From the last interglacial period to the current period, the total suitable area of T. sinense showed a decreasing trend; the distribution points of T. sinense populations in mid‐Holocene period may be the origin of the postglacial population, and Southwest China may be its glacial biological refuge. (4) Compared with the current period, the total suitable area ranges of T. sinense in China in the 2050s and 2070s decreased, and the centroid location of its total fitness area all migrated to the northwest, with the largest migration distance in 2070s under the SSPs 7.0 climate scenario. Temperature was the principal factor influencing the geographical distribution of T. sinense. With global warming, the range of T. sinense suitable areas will show a shrinking trend, with a shift toward higher‐latitude regions. Ex situ conservation measures could be taken to preserve its germplasm resources. [ABSTRACT FROM AUTHOR]

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]

Palaeoclimatic and palaeoenvironmental proxy data are presented for the Late Quaternary based on mineralogical, geochemical and palynological analysis of a palaeosoil-sediment section in the lower Kürtün Valley (Samsun region, Northern Türkiye). The geochronology along the section is established based on OSL and radiocarbon dating. The base of the palaeosoil-sediment section consists of a palaeo-terrace fill of the Kürtün Creek dated to 108 ± 9 ka, corresponding to the last interglacial period (MIS5c). After this warm and humid period, the last ice age began. Sea level dropped and the Kürtün Stream deepened its bed. Fluvial terrace deposits were covered with colluvial materials and a palaeosoil sequence formed. The bottommost part of the palaeosoil formation carries the fingerprints of a dry climate of 68 ± 9 ka ago (MIS4). The middle part of the section coincides with MIS2 (28,959 cal BP) and is characterized by humid conditions with arid pulses accompanied by the occurrences of calcrete nodules. The palaeosoil-sediment section ends with the records of MIS1 (8381 cal BP), corresponding to warmer and more humid conditions. This study emphasizes the importance of palaeosoil-calcrete formation in the lower Kürtün Valley for explaining climate changes from MIS5c to MIS1. The results are compatible with studies conducted in the Eastern Mediterranean. High-resolution multi-proxy studies are recommended to better understand the connection between local climates and global climate phenomena in the Late Quaternary. [ABSTRACT FROM AUTHOR]

Along the east coast of the South Island New Zealand, large deposits of loess formed in the Quaternary Period. In the late 1880s and early 1890s, an amateur geologist, John Hardcastle, observed the deposits around his hometown of Timaru. He formulated a theory that their origins were glacial and that as these deposits formed, they left a register of climate. This was the first time that a connection between loess deposits and climate was made, and his discovery is still recognised across the world today. However, the deposits themselves are hardly acknowledged. [ABSTRACT FROM AUTHOR]

Aim: Within the intensively‐studied, well‐documented latitudinal diversity gradient, the deep‐sea biodiversity of the present‐day Norwegian Sea stands out with its notably low diversity, constituting a steep latitudinal diversity gradient in the North Atlantic. The reason behind this has long been a topic of debate and speculation. Most prominently, it is explained by the deep‐sea glacial disturbance hypothesis, which states that harsh environmental glacial conditions negatively impacted Norwegian Sea diversities, which have not yet fully recovered. Our aim is to empirically test this hypothesis. Specific research questions are: (1) Has deep‐sea biodiversity been lower during glacials than during interglacials? (2) Was there any faunal shift at the Mid‐Brunhes Event (MBE) when the mode of glacial–interglacial climatic change was altered? Location: Norwegian Sea, deep sea (1819–2800 m), coring sites MD992277, PS1243, and M23352. Time period: 620.7–1.4 ka (Middle Pleistocene–Late Holocene). Taxa studied: Ostracoda (Crustacea). Methods: We empirically test the deep‐sea glacial disturbance hypothesis by investigating whether diversity in glacial periods is consistently lower than diversity in interglacial periods. Additionally, we apply comparative analyses to determine a potential faunal shift at the MBE, a Pleistocene event describing a fundamental shift in global climate. Results: The deep Norwegian Sea diversity was not lower during glacial periods compared to interglacial periods. Holocene diversity was exceedingly lower than that of the last glacial period. Faunal composition changed substantially between pre‐ and post‐MBE. Main conclusions: These results reject the glacial disturbance hypothesis, since the low glacial diversity is the important precondition here. The present‐day‐style deep Norwegian Sea ecosystem was established by the MBE, more specifically by MBE‐induced changes in global climate, which has led to more dynamic post‐MBE conditions. In a broader context, this implies that the MBE has played an important role in the establishment of the modern polar deep‐sea ecosystem and biodiversity in general. [ABSTRACT FROM AUTHOR]

Conservation and management of endangered species are crucial to reveal the restriction mechanisms of climate change on the distribution change pattern of endangered species. Due to human interference and a limited natural capacity for regeneration, the wild resources of Ormosia microphylla Merr. & H. Y. Chen have progressively dwindled. Therefore, this study reconstructed the historical migration dynamics of the geographical distribution of O. microphylla since the last interglacial period and analyzed its adaptation to climatic conditions, aiming to provide an important reference for the protection of O. microphylla. Using data from 40 distribution resources of O. microphylla and nine climate factors, an optimized MaxEnt model, in conjunction with ArcGIS 10.4.1 software, was used for predicting and visualizing the distribution ranges and the associated changes under historical, current, and future climate scenarios. This analysis was also used to determine the dominant climate factors constraining the distribution of species. The results show that contemporary suitable habitats of O. microphylla are primarily concentrated in the mountainous regions of southern China, including Fujian, Guangdong, Guangxi, and Guizhou. The precipitation of driest quarter (bio17), the temperature seasonality (bio4), the min temperature of coldest month (bio6), and the elevation (elev) were the key limiting factors in the current geographical distribution pattern of O. microphylla. In the SSP126 and SSP585 climate scenarios, the total suitable area of O. microphylla showed a downward trend. The change in the spatial pattern of O. microphylla shows that the increase area is less than the loss area under different climate scenarios in the future. Climate warming may cause fragmentation risk to the suitable area of O. microphylla. Therefore, the corresponding protection suggestions bear significant importance for the conservation and sustainable development of O. microphylla resources. [ABSTRACT FROM AUTHOR]

The glacial‐interglacial cycle of elements and the linkage with biological production is very important. Nonetheless, records on incorporation of elements into diatom frustules are very poor in the Southern Ocean where diatom productivity is very high. As a result, there is a big gap in our understanding of elemental cycles in association with biological production and the controlling mechanisms. Here, we documented concentrations of major, trace, and rare earth elements of diatom frustules in two cores collected from the Southern Ocean since the Last Glacial Maximum to understand changes of incorporation of these elements into diatom frustules and to investigate mechanisms for changing incorporation. We found that there are three types of glacial‐interglacial variation patterns. Most elements showed increased (decreased) concentrations during the glacial period (interglacial) with decreased (increased) diatom production in the surface water following the variation pattern of magnetic susceptibility, whereas P, Ge, and Sb showed the opposite trend following the variation pattern of biogenic opal. Li, Ni, Ag, W, U, and I showed no clear glacial‐interglacial variation pattern. These different variation patterns imply that elemental incorporation into diatom frustules are also different according to elements. Our results revealed that biologically mediated removal of most elements from surface water to deep‐sea is comparable between glacial (low diatom production with high elements assimilation) and interglacial (high diatom production with low elements assimilation) periods in the Southern Ocean. However, more removal of P, Sb, and Ge in the surface water by diatoms occurs during interglacial periods in the Southern Ocean. Key Points: Concentrations of multi‐elements within diatom frustules were documented from the Southern Ocean since the Last Glacial Maximum (LGM)Most elements were assimilated/incorporated into diatoms synchronously: high (low) during glacial (interglacial) periodsP, Ge, and Sb showed low incorporation into diatom frustules during the LGM but increased during the Holocene [ABSTRACT FROM AUTHOR]

This is a data-based analysis of how Native American interpretations of their distant past are being considered reflecting new science findings. A key science understanding developed over the past 75 years has been that Native people did not occupy North America (or any place in the so-called New World) longer than 12,000 years before present (BP), thus they could neither have experienced nor understood any event in the late Pleistocene interglacial period (128,000 BP to 11,700 BP). As called in this analysis, the Clovis glass ceiling references the popular use of Clovis spear points to represent the earliest signs of humans in North America with dates generally later than 12,000 BP. This analysis engaged with recent science findings that Native people were present in North America up to 40,000 years ago. Opening the science limits of Native presence affords a reinterpretation of the past using extant Native interpretations. As an example, Salt Spring near Death Valley is a component of an ancient Pleistocene heritage landscape that can be reconstructed using geology and Native American interpretations. Native American perspectives were derived from 404 ethnographic interviews with Numic speaking peoples, focused on 24 ancient springs near Death Valley, California, and Las Vegas, Nevada. [ABSTRACT FROM AUTHOR]

The Pleistocene was characterized by climate fluctuations with rapid transitions between glacial and interglacial periods. East Asia's land bridge dynamics and monsoon system during the Middle Pleistocene transition (MPT) further constrained species distributions and dispersals, which promoted local adaptation and species diversification, making East Asia an excellent location to study species biogeography. Cypripedium macranthos Sw. a terrestrial orchid, diverged in the Pleistocene and became widespread in Russia, China, Korea, and Japan. Many populations are now at risk due to illegal harvesting or habitat loss. With comprehensive sampling including 171 individuals among 22 populations across the entire distribution range, together with plastid DNA sequencing, we have explored the origin and impact of palaeoclimate on its spatial genetic structure and historical biogeography. Regression-based analyses commonly used in landscape genetics were also applied to investigate the effects of precipitation, temperature, and wind on gene flow. The results revealed northeastern China as the probable cradle of C. macranthos , with northeastward divergence and range expansion during the MPT, aided by monsoon shifts and wind-driven seed dispersal. Isolation by environment was detected with winter temperature as a driver for north–south divergence controlling for an effect of isolation by distance, revealing cold adaptation of the northern populations or temperature-driven genetic differentiation. We also emphasize the founder speciation of an unique variety on Rebun Island of Japan. The widespread but genetically and ecologically divergent C. macranthos populations highlight the need for more conservation attention on northern populations under global warming. [ABSTRACT FROM AUTHOR]

Aim: Species responses to global warming will depend on intraspecific diversity, yet studies of factors governing biogeographic patterns of variability are scarce. Here, we investigate the evolutionary processes underlying genetic and phenotypic diversity in the flightless and cold‐adapted grasshopper Sigaus piliferus, and project its suitable space in time. Location: Te Ika‐a‐Māui Aotearoa—North Island of New Zealand. Methods: We used mitochondrial sequences to investigate population connectivity and demographic trends using phylogeographic tools and neutrality statistics. Metric data were used to document phenotypic variation using naïve clustering. We used niche metrics to assess intraspecific niche variation, and niche modelling to investigate suitability under past and future scenarios. Multiple matrix regressions with randomization explored the processes contributing to phenotypic differentiation among grasshopper populations. Results: Niche models and demographic analyses suggest suitable space for this grasshopper was more restricted during glacial than interglacial stages. Genealogical relationships among ND2 haplotypes revealed a deep north–south split partly concordant with phenotypic and niche variation, suggesting two ecotypes that have mixed during recolonisation of the central volcanic region. Multiple matrix regressions with randomization indicate a link between climate and phenotypic differentiation inferred from leg and pronotum dimensions but not pronotum shape. Niche projections predict severe habitat reduction due to climate warming. Main conclusions: The current distribution and intraspecific diversity of S. piliferus reflect complex biogeographical scenarios consistent with Quaternary climates and volcanism. Phenotypic divergence appears adaptive. Current levels of genetic and phenotypic variation suggest adaptive potential, yet the pace of anthropogenic warming over the next 50 years could result in small populations that may collapse before adapting. Differences in niche features between diverging intraspecific lineages suggest distinct responses to climate change, and this has implications for prioritising conservation actions and management strategies. [ABSTRACT FROM AUTHOR]

The construction of high-quality genomes is fundamental for molecular studies of species. Currently, there are no published genome sequences within the Uranoscopidae family, and research on the genomic characteristics of this family is lacking. In this study, genomic analyses of seven species from the Uranoscopidae family which captured from the southeastern coast of China were conducted using next-generation sequencing technology. The results revealed that the genomic characteristics of the seven species are relatively similar. The genome sizes of the seven Uranoscopidae species ranged from 536.00 Mb to 652.49 Mb, with repeat sequence proportions between 20.09% and 36.64%, and heterozygosity levels ranging from 0.41% to 0.88%. The assembled draft genomes exhibited GC contents of these species ranging from approximately 42.14% to 43.53%. Furthermore, the mitochondrial sequences for the seven species were assembled, with sizes ranging from 14,966 to 18,446 bp. The evolutionary relationships between different species were depicted through the mapping of conserved genes, whole-genome variances and mitochondrial genome sequences. Besides, the historical effective population sizes of all species experienced rapid expansion after the Last Interglacial Period, with three species undergoing bottleneck effects. In conclusion, this study provides a reference for the subsequent construction of high-quality genomes for species within the Uranoscopidae family and offers a rich data resource for further evolutionary research. [ABSTRACT FROM AUTHOR]

Glacial terminations are marked by a re-organisation of the different components of the climate system. In particular, rapid ice sheet disintegration leads to multiple complex feedback loops that are still poorly understood. To further investigate this aspect, we use here a fully coupled Northern Hemisphere ice sheet–climate model to perform numerical experiments of the last two glacial terminations. We show that even if the first-order climate trajectory is similar for the two terminations, the difference in terms of solar insolation leads to important changes for the ice sheet–climate system. Warmer temperatures during the penultimate termination are compatible with higher sea level during the last interglacial period with respect to the Holocene. We simulate a last interglacial Greenland contribution to sea level rise of about 2 m of sea level equivalent. We also simulate warmer subsurface Southern Ocean, compatible with an additional contribution from the Antarctic ice sheet. In addition, even without considering freshwater flux to the ocean resulting from ice sheet melting, the two terminations display different Atlantic overturning circulation sensitivity, this circulation being more prone to collapses during the penultimate termination. Finally, with additional sensitivity experiments we show that, for the two terminations, the Northern Hemisphere insolation is the main driver for the ice sheet retreat even if vegetation changes have also to be taken into account to simulate the full deglaciation. Conversely, even though it impacts the temperature, greenhouse gas concentration change alone does not explain the amplitude of ice sheet retreat and only modulates its timing. [ABSTRACT FROM AUTHOR]

Boulders are ubiquitous on rocky planets and provide valuable information about planetary processes. The abundance, size, and distribution of boulders offer insights into the primary processes that form them and the secondary processes that modify their position and size. However, the roles of varying environmental processes, including cryospheric processes, are poorly known. In this study, we analyze over 20 million boulders in the northern lowlands of Mars (50–70°N) to evaluate their distribution and identify environmental factors that might influence their clustering. We used spatial statistics to quantify the degree of boulder clustering across the northern plains. We found two latitudinal trends: overall decreasing clustering with increasing latitude (50–70°N) and a sub‐trend of increased clustering at higher latitudes (65–70°N). Our findings suggest that boulder distribution patterns are linked to the latitude‐dependent mantle (LDM) and subsurface ice. Boulders exhibit higher spatial clustering at higher latitudes, where the ice is thick and continuously present, and the LDM is more pristine. Lower clustering occurs at lower latitudes or regions where the ice loss is likely during interglacial periods, and the LDM degrades, exposing more boulders of varying sizes. We also discovered an anomalous region where boulder clustering is nearly random, located on the edge of the Alba Mons Patera. This area displays distinct geophysical characteristics compared to the rest of the lowlands. Although these characteristics do not indicate a specific process for the variation of boulder distribution in this study, the data suggest a coupling between cryospheric processes and boulder evolution, warranting further research. Plain Language Summary: Boulders are common on rocky planets and can provide important information about boulder‐forming processes and displacement. We studied over 20 million boulders on the northern plains of Mars to learn more about how they are distributed across the planet and what factors might influence their placement. We found that boulders are more likely clustered in areas with more ice below the surface. We also discovered an area north of Alba Mons where boulders seem to be scattered randomly, and the surface properties are different than elsewhere in the northern plains. This may be due to the repeated deposition and removal of ice in this area, but more research is needed to fully understand these patterns. Key Points: The level of boulder clustering follows latitudinally varying mantle distribution and degradation statesThe topographic, geophysical, and surface characteristics of northern Alba Patera indicate a higher presence of subsurface iceLandscape ages across the Martian northern lowlands may affect variations in boulder distributions [ABSTRACT FROM AUTHOR]

Slopes adjacent to the Bahamian carbonate platform revealed a large variety of depositional processes. In this study, we present a synthesis summarizing 109,000 km2 of bathymetric and reflectivity data with ∼7,900 km of seismic lines and 311 m of sediment cores that were obtained over the last 50 years. These data are used to develop a conceptual model of sedimentation patterns on Quaternary carbonate slope systems and their interaction with the adjacent shallow‐water carbonate platforms. Our data highlight that during the Quaternary, factors controlling large‐scale sedimentation on Bahamian slopes have numerous similarities as they have higher sedimentation rates during interglacials. At a small scale, every slope has its own characteristics that are contemporary controlled by two main characteristics: (a) facies on the adjacent shallow‐water platform, and (b) the impact of shallow‐ and deep‐water currents. Large‐scale tectonics influence sediment deposition as it determines the position of the islands and impacts platform facies distribution. Plain Language Summary: The factors that allow sediment to be exported from carbonate platforms to the deep‐sea need discussion. To gain a better understanding of the processes involved, the sedimentary archives of the slopes connected to these carbonate platforms are consulted. The sediments encountered vary and range from grains finer than 20 μm to coarse sandy sediments, a few millimeters in size. To understand the different processes that export those different types of sediment, we analyze various slopes of the Bahamas, a well‐known pure carbonate platform system. We used both numerical data (bathymetry, reflectivity, seismic) and sediment samples from this area and compared those records for the different Bahamian slopes. We highlighted that every slope displays a different sediment record; for every slope transect the adjacent platform facies together with deep‐sea processes (currents) determine the sediment distribution. The processes that export and transport the sediments are of equal importance. Key Points: Main factors controlling Bahamian slope sedimentation are revisedNumerous data types acquired offshore were synthesizedOur data suggest a strong influence of platform fine‐grained concentration and currents on slope sedimentation models [ABSTRACT FROM AUTHOR]

To explore the main controlling mechanism of hydroclimatic conditions during the last deglaciation on eastern Tibetan Plateau (TP), clay mineral records in Xinmocun lacustrine sediments were analyzed. The results indicate that high illite + chlorite contents (>92%) in the section represent the primary product of strong physical weathering in a tectonically active area. The chemical weathering index (IC) was used to monitor hydrological changes in the section. Under the transition from glacial to interglacial periods, the fluctuation amplitude of IC during humid periods was greater than that during dry periods. The IC demonstrates changes in hydrological conditions on a millennial scale. From 18.7 to 16.8 ka, high values of IC and illite crystallinity suggest strong hydrolysis in humid conditions. From 16.8 to 11.7 ka, low IC values suggest weak hydrolysis during a five-millennium long dry period, which was followed by a more humid period from 11.7 to 10.5 ka. The overall arid hydrological conditions during the last deglaciation on eastern TP probably resulted from northward shift of the intertropical convergence zone driven by enhanced insolation, leading to the extension of the Indian monsoon to the interior of East Asia. Our findings suggest that the Indian summer monsoon has dominated hydrological conditions on eastern TP since the onset of deglaciation at approximately 16.8 ka. [ABSTRACT FROM AUTHOR]

The Agulhas Return Current (ARC) transports warm tropical and subtropical waters eastward into the southern Indian Ocean. It plays a crucial role in the oceanographic connections between the Indian, Atlantic, and Southern oceans. Modern oceanographic observations show that the latitudinal position of the ARC varies interannually. However, its historical positional variations remain poorly understood. Calcareous nannofossils can be a good indicator of ancient current migration, although their record in the Southwest Indian Ocean is poorly studied. This research aims to understand the characteristics and downcore variation of the calcareous nannofossil assemblages and trace the record of the ancient ARC. To achieve these goals, this study analyzed pelagic sediments of multicore 34IV-SWIR-S021MC03, 34IV-SWIR-S032MC04, and 34IV-SWIR-S040MC05 from the Southwest Indian Ocean. A total of 13 nannofossil species have been identified. The assemblages belong to the subtropical convergence zone regime. They are characterized by warm and cold water species, dominated by Emiliania huxleyi, Calcidiscus leptoporus, Gephyrocapsa muellerae, and Florisphaera profunda. According to the AMS[sup 14]C age model and phytoplankton ecological signatures, this study establishes a calcareous nannofossil indicator to trace the migration of the ancient ARC during the last 40 kyr. The result shows three periods of migration: 40-22 kyr, the ancient ARC was in the far north and was moving southward; 22-14 kyr, a transitional period, the ancient ARC was moving northward; 14-3 kyr, the ARC was moving southward. This further suggests that the migration of the ancient ARC is more complex than the two recognized phases, and there were essential turning points around the last glacial maximum period. It also acknowledges that the ancient ARC is sensitive to interglacial periods and can be influenced simultaneously by the Southern Hemisphere monsoon and westerly winds. [ABSTRACT FROM AUTHOR]

Past intervals of warming provide the unique opportunity to observe how the East Asia monsoon precipitation response happened in a warming world. However, the available evaluations are primarily limited to the last glacial-to-interglacial warming, which has fundamental differences from the current interglacial warming, particularly in changes in ice volume. Comparative paleoclimate studies of earlier warm interglacial periods can provide more realistic analogs. Here, we present high-resolution quantitative reconstructions of temperature and precipitation from north-central China over the past 800 thousand years. We found that the average precipitation increase, estimated by the interglacial data, was only around one-half of that estimated for the glacialto-interglacial data, which is attributed to the amplification of climate change by ice volume variations. Analysis of the interglacial data suggests an increase in monsoon precipitation of ~100 mm for a warming level of 2°C on the Chinese Loess Plateau. [ABSTRACT FROM AUTHOR]

Simple Summary: This study focuses on the assassin bug Sycanus bifidus, a widespread species in southern China, by analyzing its genetic data to trace how the Pleistocene's climate and geography influenced its distribution and evolution. There are two main genetic groups, which suggests that past climatic conditions and sea-level rises, especially concerning Hainan Island, profoundly impacted the spread and distribution of these bugs. This study's insights into the assassin bugs' historical population dynamics and adaptations to environmental changes emphasize the role of historical climatic fluctuations in shaping the distribution of species. 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. [ABSTRACT FROM AUTHOR]

Hybridization and introgression are recognized as mechanisms promoting genetic variability during evolutionary radiations. We examined the impact of introgression in the process of speciation, focusing on the Antarctic icefish genus Chionodraco. Our analyses confirmed that the three Chionodraco species (Chionodraco hamatus, Chionodraco myersi , and Chionodraco rastrospinosus) were genetically distinctive, despite signals of past interspecific gene flow between C. hamatus and C. myersi that likely occurred during interglacial periods. However, in this study, no recent hybrids were identified. The lack of contemporary hybridization may be due to life-history traits and the type of marker used in the analysis. Our study emphasizes the importance of genomic approaches to detect subtle patterns of past hybridization accurately and highlights the significance of historical climate events in the demographic and evolutionary history of Antarctic notothenioids. Polar regions, and especially the Antarctic Peninsula, are now experiencing the fastest climate changes due to global warming. Understanding the impact of past climate events is fundamental to trace current modifications in species' genetic variability and distributions and predict future evolutionary trajectories. This knowledge is also vital for conservation efforts, including the implementation of marine protected areas. [ABSTRACT FROM AUTHOR]

Glacial-interglacial cycles are characteristic of the large-scale reorganisation of global climate during the Quaternary. Therefore, records of warmer-than-present periods, such as the Marine Isotope Stage (MIS) 5e, draw particular interest as they may aid scientists to predict how marine ecosystems may change in the future. However, fish fossil records during such warming periods are less clear. Here, we aim to reconstruct local fish fauna during the MIS 5e by describing fossil otoliths from two localities in central Japan belonging to the Otsu Sand and Mud Member of the Yokosuka Formation. A total of 544 otoliths were analysed, revealing the presence of at least 35 taxa. The fish assemblages reflect a mixture of coastal to oceanic epi-mesopelagic species. In addition, the remarkable occurrences of two present-day tropical species and its species composition demonstrate a possible complex tropical to subtropical-like fish fauna in the higher latitude Palaeo-Tokyo Bay during the warmer-than-present last interglacial period. [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]

The terrestrial magnetic minerals of marine sediments are utilized to track the climatic changes in the source area and the dynamic characteristics of sedimentation processes. However, due to the varied source‐to‐sink environments, the magnetic response to ambient climate cannot be generalized. Here, we conducted systematic environmental magnetic analyses on core CJ04‐50 from the Ninetyeast Ridge and investigated its magnetic response to source‐to‐sink environmental changes. Core CJ04‐50 covers the last 60 Kyr based on accelerator mass spectrometry (AMS) 14C dating and the relative paleointensity (RPI) record. Rare earth element (REE) results suggest that the terrestrial materials are fed by the Ganges‐Brahmaputra (G‐B) and Irrawaddy/Indo‐Burma Ranges. High/low magnetic mineral content corresponds to strong/weak terristrial input during the cold/warm period. This pattern differs from that in the East Asian marginal seas, which have a high magnetic mineral content in warm periods. It might be attributed to the heavier Indian summer monsoon (ISM) precipitation than that of East Asian summer monsoon. Excessive moisture (>1,500 mm/year) would not favor the formation and preservation of magnetic minerals in the source area during interglacials. By contrast, the enhanced physical weathering during glacials results in more magnetic contributions. A significant local magnetite dissolution occurred at the layer of Middle MIS 3, which may be caused by the non‐steady state diagenesis following deposition. Plain Language Summary: Magnetic minerals in marine sediments can record climate and environmental change information, which vary with the source‐to‐sink environmental changes. Here, we extracted magnetic mineral signals from sediments in the Ninetyeast Ridge since the last 60 Kyr. We found that the Ganges‐Brahmaputra (G‐B) and Irrawaddy Rivers are the major detrital sources. The magnetic mineral concentration of the Bay of Bengal is high in glacial period but low in interglacial period, unlike that of East Asian marginal marine sediments. It may be caused by the different monsoon precipitations in South Asia and East Asia. The heavier Indian summer monsoon (ISM) precipitation may result in poor magnetic preservation. In addition, a magnetite dissolution is detected at the layer of Middle MIS 3, which may be caused by a local deep‐sea environmental shift. Key Points: Millennial environmental magnetic records in Ninetyeast Ridge from the past 60 Kyr are reportedDifferent summer monsoon precipitations lead to divergent magnetic responses to chemical weathering in East and South AsiaA local magnetite dissolution was detected at the layer of middle MIS 3 caused by the non‐steady state diagenesis following deposition [ABSTRACT FROM AUTHOR]

High‐resolution records from past interglacial climates help constrain future responses to global warming, yet are rare. Here, we produce seasonally resolved climate records from subarctic‐Canada using micron‐scale measurements of oxygen isotopes (δ18O) in speleothems with apparent annual growth bands from three interglacial periods—Marine Isotope Stages (MIS) 11, 9, and 5e. We find 3‰ lower δ18O values during MIS 11 than MIS 5e, despite MIS 11 likely being warmer. We explore controls on high‐latitude speleothem δ18O and suggest low MIS 11 δ18O values reflect greater contribution of cold‐season precipitation to dripwater from longer annual ground thaw durations. Other potential influences include changes in precipitation source and/or increased fraction of cold‐season precipitation from diminished sea ice in MIS 11. Our study highlights the potential for high‐latitude speleothems to yield detailed isotopic records of Northern Hemisphere interglacial climates beyond the reach of Greenland ice cores and offers a framework for interpreting them. Plain Language Summary: Few climate records pre‐dating the last ice age exist from high‐latitude North America, which inhibits our understanding of how regions with permafrost responded to past warming and how they might change in the future. Here, we help fill this data gap by using six speleothems (cave mineral deposits) from a cave in the Northwest Territories, Canada to produce climate records that span thousands of years during former warm periods of Earth's history. We find that speleothems that grew during an exceptionally warm super‐interglacial period 400,000 years ago have 3‰ lower oxygen isotope (δ18O) values compared to those that grew during a likely cooler interglacial 125,000 years ago. We explore potential explanations for the difference in δ18O across interglacials, and suggest that lower δ18O values during warmer periods reflect greater infiltration of cool‐season precipitation with longer annual ground thaw durations. This study highlights the importance of high‐latitude speleothems to provide detailed climate records beyond the range available from Greenland ice cores. Key Points: Long high‐latitude terrestrial climate records are rare in the Northern HemisphereHigh‐latitude speleothems can provide ultra‐high‐resolution climate records beyond the reach of Greenland ice coresMean oxygen isotopes of Arctic and subarctic speleothems likely are controlled by annual ground thaw durations [ABSTRACT FROM AUTHOR]

Evolutionary processes behind lineage divergence often involve multidimensional differentiation. However, in the context of recent divergences, the signals exhibited by each dimension may not converge. In such scenarios, incomplete lineage sorting, gene flow, and scarce phenotypic differentiation are pervasive. Here, we integrated genomic (RAD loci of 90 individuals), phenotypic (linear and geometric traits of 823 and 411 individuals, respectively), spatial, and climatic data to reconstruct the evolutionary history of a speciation continuum of liolaemid lizards (Liolaemus kingii group). Specifically, we (a) inferred the population structure of the group and contrasted it with the phenotypic variability; (b) assessed the role of postdivergence gene flow in shaping phylogeographic and phenotypic patterns; and (c) explored ecogeographic drivers of diversification across time and space. We inferred eight genomic clusters exhibiting leaky genetic borders coincident with geographic transitions. We also found evidence of postdivergence gene flow resulting in transgressive phenotypic evolution in one species. Predicted ancestral niches unveiled suitable areas in southern and eastern Patagonia during glacial and interglacial periods. Our study underscores integrating different data and model-based approaches to determine the underlying causes of diversification, a challenge faced in the study of recently diverged groups. We also highlight Liolaemus as a model system for phylogeographic and broader evolutionary studies. [ABSTRACT FROM AUTHOR]

The freshwater discharge from melting ice sheets in the deglaciation or glaciation is prone to anomalies in ocean-atmosphere transport between different latitudes, which can lead to a series of abrupt millennial-scale climate events, either obvious or not, such as the Younger Dryas (YD) events and YD-like events. Marine Isotope Stage 11c (MIS 11c) serves as one of the best references for the current Holocene, and the studies of possible YD-like events and their triggering mechanisms during Holocene are conducive to the understanding of the occurrence pattern of extreme climate events. In this paper, the results of the study on the J33 δ18O sequence records of stalagmites in Jinfo Cave, Chongqing, are shown: (1) Stalagmites in the Asian monsoon climate zone reveal a millennial-scale weak monsoon event that occurred around 410 ka BP prior to the Glacial Maximum of MIS 11 interglacial period. (2) Both the 410 ka weak monsoon event and the YD event occurred during the gradual strengthening of the monsoon and ascending branch of summer insolation in the Northern Hemisphere prior to the Glacial Maximum of interglacial period. This was also a time when Atlantic Meridional Overturning Circulation (AMOC) disturbance occurred. The duration, internal structure, and pattern of the events were similar, with differences in the change magnitude and ice volume conditions. (3) The weak monsoon event that occurred in 410 ka BP was primarily influenced by the combined effects of insolation and AMOC. This event was characterized by a sustained warming process that accelerated the melting of the Greenland ice sheet, leading to the destabilization of this ice sheet. The continuous flowing of freshwater into the North Atlantic resulted in a short-lived AMOC oscillation. The weakening of the AMOC resulted in a cold anomaly over the North Atlantic. As a result of atmospheric telecorrelation, the weaker AMOC led to a weaker Asian Summer Monsoon (ASM). [ABSTRACT FROM AUTHOR]

Understanding the microscopic variability of impurities in glacier ice on a quantitative level has importance for assessing the preservation of paleoclimatic signals and enables the study of macroscopic deformational as well as dielectric ice properties. Two‐dimensional imaging via laser‐ablation‐inductively‐coupled‐plasma‐mass‐spectrometry (LA‐ICP‐MS) can provide key insight into the localization of impurities in the ice. So far, these findings are mostly qualitative and gaining quantitative insights remains challenging. Recent advances in LA‐ICP‐MS high‐resolution imaging now allow ice grains and grain boundaries to be resolved individually. These resolutions require new adequate quantification strategies and, consequently, accurate calibration with matrix‐matched standards. Here, we present three different quantification methods, which provide a high level of homogeneity at the scale of a few tens of microns and are dedicated to imaging applications of ice cores. One of the proposed methods has a second application, offering laboratory experiments to investigate the displacement of impurities by grain growth, with important future potential to study ice‐impurity interactions. Standards were analyzed to enable absolute quantification of impurities in selected ice core samples. Calibrated LA‐ICP‐MS maps indicate similar spatial distributions of impurities in all samples, while impurity levels vary distinctly: Higher concentrations were detected in glacial periods and Greenland, and lower levels in interglacial periods and samples from central Antarctica. These results are consistent with ranges from complementary meltwater analysis. Further comparison with cm‐scale melting techniques calls for a more sophisticated understanding of the ice chemistry across spatial scales, to which calibrated LA‐ICP‐MS maps now contribute quantitatively. Plain Language Summary: Compared to the large amount of information relating to paleoclimate signals reconstructed from cm‐scale impurity measurements on ice cores, knowledge about the spatial variability of impurities at the micro‐scale is extremely sparse—and becomes even more rare once quantitative datasets are concerned. However, there is an increasing demand for quantitative data for assessing the preservation of paleoclimatic signals and for the study of macroscopic deformational as well as dielectric ice properties in ice flow modeling and remote sensing. Two‐dimensional imaging via laser‐ablation‐inductively‐coupled‐plasma‐mass‐spectrometry (LA‐ICP‐MS) has shown great potential in this context, but so far, gaining reliable quantitative results for micro‐scale imaging has not been possible. Here, we present new quantification strategies that finally allow accurate calibration using ice standards. We carefully discuss the pros and cons of each method, apply the calibration to different samples from Greenland and Antarctica, and deliver the first calibrated LA‐ICP‐MS impurity maps at 40 μm resolution. Our results are consistent with bulk measurements performed on melted samples. The calibrated LA‐ICP‐MS maps will be essential for further comparison with bulk meltwater analysis, which may ultimately deliver an improved understanding of paleoclimate signals stored in deep ice. Key Points: This study presents new quantification strategies for two‐dimensional micro‐scale impurity imaging on ice cores with laser‐ablation‐inductively‐coupled‐plasma‐mass‐spectrometry (LA‐ICP‐MS)Calibrated LA‐ICP‐MS maps reveal similar spatial distributions of impurities in all ice core samples, while concentrations vary distinctlyWe developed a method to investigate the displacement of impurities by grain growth and to study ice‐impurity interactions in the laboratory [ABSTRACT FROM AUTHOR]

During the Quaternary, ice sheets experienced several retreat-advanced cycles, strongly influencing climate patterns. In order to properly simulate these phenomena, it is preferable to use physics-based models instead of parameterizations to estimate surface mass balance (SMB) which has a strong influence on the ice sheet evolution. To further investigate the potential of these SMB models, this work evaluates BESSI (BErgen Snow Simulator), a multi-layer snow model with high computational efficiency, as an alternative to providing SMB for paleo studies. First, we validate the snow model using the regional climate model MAR (Modεave;le Atmosphérique Régional) as forcing and reference for the present-day climate over Greenland and Antarctic Ice Sheets. The evolution of SMB over the Last Interglacial period (LIG) (130–116 kaBP) is computed by forcing BESSI with transient climate forcing obtained from an Earth system model i LOVECLIM for both ice sheets. For present-day climate conditions, BESSI exhibits good performance compared to MAR despite a much simpler model set-up. The model also captures well the variation of SMB and its components during the LIG. Compared to the current simple melt estimation scheme of i LOVECLIM (ITM), BESSI is able to capture different SMB patterns for two particular ice sheet climate conditions thanks to its higher physical constraints while ITM displays a strong sensitivity to its parameters and input fields (temperature). The findings suggest that BESSI can provide more reliable SMB estimations for the i LOVECLIM framework to improve the model simulations of the ice sheet evolution and interactions with climate. [ABSTRACT FROM AUTHOR]

The Qinling Mountains in East Asia serve as the geographical boundary between the north and south of China and are also indicative of climatic differences, resulting in rich ecological and species diversity. However, few studies have focused on the responses of plants to geological and climatic changes in the Qinling Mountains and adjacent regions. Therefore, we investigated the evolutionary origins and phylogenetic relationships of three Pedicularis species in there to provide molecular evidence for the origin and evolution of plant species. Ecological niche modeling was used to predict the geographic distributions of three Pedicularis species during the last interglacial period, the last glacial maximum period, and current and future periods, respectively. Furthermore, the distribution patterns of climate fluctuations and the niche dynamics framework were used to assess the equivalence or difference of niches among three Pedicularis species. The results revealed that the divergence of three Pedicularis species took place in the Miocene and Holocene periods, which was significantly associated with the large-scale uplifts of the Qinling Mountains and adjacent regions. In addition, the geographic distributions of three Pedicularis species have undergone a northward migration from the past to the future. The most important environmental variables affecting the geographic distributions of species were the mean diurnal range and annual mean temperature range. The niche divergence analysis suggested that the three Pedicularis species have similar ecological niches. Among them, P. giraldiana showed the highest niche breadth, covering nearly all of the climatic niche spaces of P. dissecta and P. bicolor. In summary, this study provides novel insights into the divergence and origins of three Pedicularis species and their responses to climate and geological changes in the Qinling Mountains and adjacent regions. The findings have also provided new perspectives for the conservation and management of Pedicularis species. [ABSTRACT FROM AUTHOR]

The California Current system (CCS) hosts one of the largest oxygen minimum zones (OMZs) in the world: the eastern North Pacific (ENP) OMZ, which is dissociated into subtropical and tropical regions (i.e. the ESTNP and ETNP). In the modern ENP OMZ, bioavailable nitrogen (N) is lost via denitrification and anaerobic ammonium oxidation (anammox). Even so, paleo-reconstructions of N loss have focused solely on denitrification. Fluctuations in bulk sedimentary δ15 N over glacial–interglacial cycles have been interpreted to reflect variations in denitrification rates in response to ETNP OMZ intensity changes. This δ15 N signal is thought to be transported northwards to the ESTNP OMZ. Here, we present the first CCS sedimentary record of ladderane lipids, biomarkers for anammox, located within the ESTNP OMZ (32° N, 118° W). Over the last two glacial terminations (∼ 160 kyr cal BP), ladderane concentrations were analysed in combination with the index of ladderanes with five cyclobutane moieties (NL 5), short-chain (SC) ladderane degradation products, and productivity proxies. This shows that (1) ladderanes were derived from anammox bacteria living within the ESTNP OMZ water column; (2) ladderanes were continuously present, with relatively high concentrations during both glacial and interglacial periods, showcasing that the ESTNP OMZ must have retained an anoxic core in which N loss occurred; and (3) anammox abundance appears to have been driven by both organic matter (OM) remineralization and advection changes, which regulated nutrient and oxygen levels. Our study shows that anammox was an important feature in the CCS, and it provides a more holistic picture of N-loss dynamics and the development of the ESTNP OMZ over glacial–interglacial cycles. Lastly, ladderanes and their SC products were also detected in 160–500 kyr cal BP sediments (15.7–37.5 m b.s.f., metres below sea floor; analysed at a low temporal resolution), highlighting their potential as anammox biomarkers in relatively deeper buried sediments for future studies. [ABSTRACT FROM AUTHOR]

Aim: Similar environmental selection pressures drive the occurrence of convergent evolution among species. However, studies on this phenomenon are scarce at the population level. Here, we used two waist‐shaped bugs to test the hypothesis that similar high‐elevation habitat environments could lead to similar genetic adaptations among populations of different species. Location: East Asia. Taxa: Malcus sinicus Štys, 1967 & Malcus insularis Štys, 1967. Methods: Population genetic structure was determined by phylogenetic and phylogeographical analyses. Demographic history was inferred by comparing simulated history models. Suitable habitat from the last interglacial period (LIG) to the present was predicted by ecological niche modelling (ENM). Convergent evolutionary processes were jointly assessed by the comparison of population ecological differences and the principal component analysis of environmentally related single‐nucleotide polymorphisms (SNPs). Results: Our results showed that the land bridge in the Pleistocene helped ancestral populations of M. sinicus and M. insularis diffuse from mainland China to Taiwan Island. Subsequently, the geographical barrier imposed by the Taiwan Strait promoted the species differentiation. Geographic isolation and adaptive evolution jointly promoted the population differentiation in M. sinicus. Genetic similarity was found between the populations of M. sinicus in southwestern China (sin‐YN) and M. insularis on Taiwan Island (ins‐TW). Temperature‐related environmental factors and elevation were found to similarly and significantly clustered with ins‐TW and sin‐YN and were clearly distinguished from the other low−/mid‐elevation populations of M. sinicus (sin‐EA). Furthermore, the SNPs related to these environmental factors presented the same clustering results. Main Conclusions: Our study revealed a novel disjunct distribution pattern between southwestern China and Taiwan Island at the population level and provided evidence of convergent evolution of local populations in high‐elevation environments. Here, we revealed that similar environmental selection pressures can drive the occurrence of convergent evolution at the population level among different species. [ABSTRACT FROM AUTHOR]

The dugong (Dugong dugon) is a marine mammal widely distributed throughout the Indo-Pacific and the Red Sea, with a Vulnerable conservation status, and little is known about many of the more peripheral populations, some of which are thought to be close to extinction. We present a de novo high-quality genome assembly for the dugong from an individual belonging to the well-monitored Moreton Bay population in Queensland, Australia. Our assembly uses long-read PacBio HiFi sequencing and Omni-C data following the Vertebrate Genome Project pipeline to reach chromosome-level contiguity (24 chromosome-level scaffolds; 3.16 Gbp) and high completeness (97.9% complete BUSCOs). We observed relatively high genome-wide heterozygosity, which likely reflects historical population abundance before the last interglacial period, approximately 125,000 yr ago. Demographic inference suggests that dugong populations began declining as sea levels fell after the last interglacial period, likely a result of population fragmentation and habitat loss due to the exposure of seagrass meadows. We find no evidence for ongoing recent inbreeding in this individual. However, runs of homozygosity indicate some past inbreeding. Our draft genome assembly will enable range-wide assessments of genetic diversity and adaptation, facilitate effective management of dugong populations, and allow comparative genomics analyses including with other sirenians, the oldest marine mammal lineage. [ABSTRACT FROM AUTHOR]

Eriophyoid mites are among the most species‐rich superfamilies (Eriophyoidea) in the Acari, consisting of over 5000 named species. Although they exhibit a geographically uneven worldwide distribution, their regional spatiotemporal evolutionary patterns remain largely unknown. Here, we compiled a data set including 3058 occurrence records assigned into 1203 species in China. We found that eriophyoid mite species richness is higher in the southeast and lower in the northwest of China, coinciding with the 500‐mm annual precipitation isoline. Using fragments of two mitochondrial genes (COI, 12S rRNA) and two nuclear genes (18S rRNA, 28S rRNA) of 304 eriophyoid mite species, we constructed a regional dated phylogenetic tree in China. Our spatiotemporal analysis revealed that mountains in eastern and southern China had high eriophyoid mite species richness and phylogenetic clustering, possessing both ancient and young mite lineages. Species distribution modelling (SDM) results showed that the predicted suitable area of eriophyoid mites slightly expanded from the last inter‐glacial period to the last glacial maximum period. In comparison with the current SDM, a significantly larger distribution range was observed in future scenarios. These findings suggest that mountains in eastern and southern China acted as not only cradles—recent rapid speciation, but also museums—centre of gradual accumulation and preservation and provide insights into monitoring and conserving eriophyoid mites. [ABSTRACT FROM AUTHOR]

Neoproterozoic strata are widely developed in the Upper Yangtze region of South China, among which the Sinian Dengying Formation has been discovered with numerous large gas fields in the Sichuan Basin, and hence they have become an essential domain for natural gas exploration and development. The early‐to‐middle Neoproterozoic Nanhua System and Doushantuo Formation are characterized by rifting deposits in the northeastern margin of Sichuan Basin, but their depositional succession and sequence architectures are still unclear, which has largely restricted our understanding of the resource potential of these strata. In this paper, based on the outcrops of the Neoproterozoic Nanhua System and Doushantuo Formation in the northeastern margin of Sichuan Basin, we describe the stratigraphic distribution and sedimentary evolutionary characteristics, and establish the regional stratigraphic framework, sedimentary cycle and evolutionary sequence of the Nanhua System and Doushantuo Formation. The results show that the lithology of the Nanhua System and Doushantuo Formation is primarily composed of conglomerate, conglomeratic sandstone, medium‐fine sandstone, siltstone, mudstone, shale and tillite; a variety of sedimentary facies including alluvial fan, river, delta, coastal shore, shelf, basin and tillite were developed; five third‐order sequences could be identified, representing multiple cycles of marine transgression and regression. The climate during the deposition of the Nanhua System and Doushantuo Formation underwent from a warm and humid pre‐glacial period through cold and arid multiple glacial periods to a warm and humid interglacial period, which consequently formed a sedimentary sequence of alluvial fan and fluvial delta to tillite during the early period, shelf basin to tillite during the middle period and slope basin to delta facies during the late period. In terms of a plan view, the depositional pattern is composed of alluvial fans and deltas at the proximal part of the rift, deep‐water shelf to slope at the middle part of the rift and slope to basin facies at the central part of the rift. Finally, we propose that large‐scale distribution of high‐quality source rocks developed in the interglacial Datangpo and Doushantuo formations, while fluvial‐deltaic reservoirs occurred in the Gucheng, Nantuo and Doushantuo formations, thus showing favourable resource potential and exploration prospects within the Sichuan Basin. [ABSTRACT FROM AUTHOR]

The southern three-banded armadillo, Tolypeutes matacus , is one of the most representative species of the South American Chaco region. The susceptibility of this species to climatic changes and its good number of paleontological records has led to the study of their range dynamics for untangling the effects of Quaternary oscillations. These studies yielded contradictory results, suggesting expansion processes under opposite conditions: some during glacial periods and others during interglacial periods. Here, we assess the population structure of T. matacus in Argentina based on mitochondrial genes, and estimate demographic and spatial dynamics that contribute to unveiling the evolutionary process that moulded its biogeography. We found no clear phylogeographical breaks, although there were differences in the composition and frequency of haplotypes between the northern and southern localities studied. Demographic inferences indicate that the species has undergone population and range expansion processes. The higher diversity found in the north and the spatial diffusion analysis allow us to infer a north–south direction of this expansive process. Our results yield essential evidence for disentangling the evolution of this Chacoan species linked with Quaternary climates and provide genetic information about its populations that should be taken into account for the conservation of this threatened mammal. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Recognizing Loudetia‐dominated grasslands were widespread prior to human colonization highlights that open ecosystems were and continue to be an important component of Madagascar's biodiversity. A better understanding of the plant species that form grassland ecosystems is necessary for effective land management strategies that support livelihoods, but substantial financial and logistical barriers exist to implementing conservation genetic studies using contemporary genomic tools. Some challenges for population genetic analyses of non‐model polyploids lacking reference genomes can be ameliorated by developing computational resources that leverage a cost‐effective data generation strategy that requires no prior genetic knowledge of the target species. This may benefit conservation programs with small operating budgets while reducing uncertainty compared to status quo microsatellite assays. Summary: The extent of Madagascar's grasslands prior to human colonization is unresolved. We used population genetic analyses of a broadly dominant C4 fire‐adapted grass, Loudetia simplex, as a proxy for estimating grassland change through time. We carefully examined the utility of target‐enrichment data for population genetics to make recommendations for conservation genetics. We explored the potential of estimating individual ploidy levels from target‐enrichment data and how assumptions about ploidy could affect analyses.We developed a novel bioinformatic pipeline to estimate ploidy and genotypes from target‐enrichment data. We estimated standard population genetic summary statistics in addition to species trees and population structure. Extended Bayesian skyline plots provided estimates of population size through time for empirical and simulated data.All Malagasy L. simplex individuals sampled in this study formed a clade and possibly indicated an ancestral Central Highland distribution of 800 m in altitude and above. Demographic models suggested grassland expansions occurred prior to the Last Interglacial Period and supported extensive grasslands prior to human colonization. Though there are limitations to target‐enrichment data for population genetic studies, we find that analyses of population structure are reliable.Genetic variation in L. simplex supports widespread grasslands in Madagascar prior to the more recent periods of notable paleoclimatic change. However, the methods explored here could not differentiate between paleoclimatic change near the Last Glacial Maximum and anthropogenic effects. Target‐enrichment data can be a valuable tool for analyses of population structure in the absence a reference genome. [ABSTRACT FROM AUTHOR]

Methane hydrates are widely distributed along continental margins, representing a potential source of methane to the ocean and atmosphere, possibly influencing Earth's climate. Yet, little is known about the response of methane hydrates to global climate change, especially at the timescale of glacial-interglacial cycles. Here we present a chronology of methane seepage from seep carbonates derived from a series of tens to hundreds of meters long hydrate-bearing sediment records from the South China Sea, drilled at water depths of 664-871 m. We find that six out of seven episodes of intense methane seepage during the last 440,000 years were related to hydrate dissociation, all coinciding with major interglacials, the so-called Marine Isotope Stages 1, 5e, 7c, 9c, and 11c. Using numerical modeling, we show that these events of methane hydrate instability were possibly triggered by the rapid warming of intermediate waters by ~2.5-3.5 °C in the South China Sea. This finding provides direct evidence for the sensitivity of the deep marine methane hydrate reservoir to glacial-interglacial climatic and oceanographic cyclicity. [ABSTRACT FROM AUTHOR]

The blue whale, Balaenoptera musculus , is the largest animal known to have ever existed, making it an important case study in longevity and resistance to cancer. To further this and other blue whale-related research, we report a reference-quality, long-read-based genome assembly of this fascinating species. We assembled the genome from PacBio long reads and utilized Illumina/10×, optical maps, and Hi-C data for scaffolding, polishing, and manual curation. We also provided long read RNA-seq data to facilitate the annotation of the assembly by NCBI and Ensembl. Additionally, we annotated both haplotypes using TOGA and measured the genome size by flow cytometry. We then compared the blue whale genome with other cetaceans and artiodactyls, including vaquita (Phocoena sinus), the world's smallest cetacean, to investigate blue whale's unique biological traits. We found a dramatic amplification of several genes in the blue whale genome resulting from a recent burst in segmental duplications, though the possible connection between this amplification and giant body size requires further study. We also discovered sites in the insulin-like growth factor-1 gene correlated with body size in cetaceans. Finally, using our assembly to examine the heterozygosity and historical demography of Pacific and Atlantic blue whale populations, we found that the genomes of both populations are highly heterozygous and that their genetic isolation dates to the last interglacial period. Taken together, these results indicate how a high-quality, annotated blue whale genome will serve as an important resource for biology, evolution, and conservation research. [ABSTRACT FROM AUTHOR]

Seven published and four new pollen records from well-dated sediment cores from six Pleistocene and Holocene maar structures located in the Eifel, Germany, are combined to a pollen stack that covers the entire last 132,000 years. This stack is complemented by new macroremain data from one additional sediment core. The pollen data included into the stack show consistently that the Eifel was covered by a dense forest during the Eemian, early Marine Isotope Stage (MIS) 3, and the Holocene. While other European records indeed indicate a warming, the early MIS 3 fully developed forest remains a unique feature in central European pollen records. Comparison to orbital parameters and insolation hints to warm and humid, however, not fully interglacial conditions, which are also visible in speleothem growth throughout Europe. With the cooling trend towards the glacial maxima of MIS 4 and 2, tree pollen declined, with recovering phases during MIS 5c and 5a, as well as during all MIS 3 interglacials. During the colder stadials, steppe vegetation expanded. For MIS 5 and 4, we defined six new landscape evolution zones based on pollen and macroremains. [ABSTRACT FROM AUTHOR]

The Maldives Archipelago (Indian Ocean), composed of two rows of atolls that enclose an inner sea, offers an excellent study site to explore the forcings of carbonate production at platforms. Glacial–interglacial sea-level changes have been claimed to be the main factor controlling the carbonate platform factories; however, climatic factors may also have an impact. In this work we used geochemical compositional records, obtained by X-ray fluorescence (XRF) core-scanning from the International Ocean Discovery Program (IODP) Site U1467 in the Maldives Inner Sea, to analyze the orbitally driven fluctuations on the carbonate production and export from the neritic environment into the Maldives Inner Sea over the last 1.3 million years. High Sr aragonite-rich carbonates (HSAC) from neritic settings were deposited in the Maldives Inner Sea during sea-level highstand intervals, increasing the Sr/Ca values. In contrast, low Sr/Ca values are observed coincident with sea-level lowstand periods, suggesting that large areas of the atolls were exposed or unable to grow, and therefore, there was a demise in the carbonate production and sediment export to the Maldives Inner Sea. However, comparison of the Sr/Ca values and the sea-level reconstructions for different interglacial periods before and after the mid-Brunhes event (MBE, ∼ 430 ka) indicates that sea level is not the only factor controlling the production of HSAC during sea-level highstands. The study of monsoon and primary productivity proxies (Fe -normalized, Fe/K , and Br -normalized records) from the same site suggests that the intensity of the summer monsoon and the Indian Ocean dipole probably modulated the carbonate production at the atolls. Moreover, Marine Isotope Stage 11 stands out as a period with high sea level and extraordinary carbonate production in the Maldives platform. This outstanding carbonate production in the Maldives atolls (and in other low-latitude carbonate platforms) probably contributed to the mid-Brunhes dissolution event through a strong shelf-to-basin fractionation of carbonate deposition. [ABSTRACT FROM AUTHOR]

To extract climatically relevant chemical signals from the deepest, oldest Antarctic ice, we must first understand the degree to which chemical ions diffuse within solid ice. Volcanic sulfate peaks are the ideal target for such an investigation because they are high amplitude, short duration (~3 years) events with a quasi-uniform structure. Here we present analysis of the EPICA Dome C sulfate record over the last 450 kyr. We identify volcanic peaks and isolate them from the non-sea salt sulfate background to reveal the effects of diffusion: amplitude damping and broadening of peaks in the time domain with increasing depth/age. Sulfate peak shape is also altered by the thinning of ice layers with depth that results from ice flow. Both processes must be simulated to derive effective diffusion rates. This is achieved by running a forward model to diffuse idealised sulfate peaks at different rates while also accounting for ice thinning. Our simulations suggest a median effective diffusion rate of sulfate ions of 2.4 ± 1.7 x 10-7 m2 yr-1 in the Holocene ice, slightly faster than suggested by previous work. The effective diffusion rate observed in deeper ice is significantly lower, and the Holocene ice shows the highest rate of the last 450 kyr. Beyond the Holocene, there is no systematic difference between the effective diffusion rates of glacial and interglacial periods despite variations in soluble ions concentrations, dust loading and ice grain radii. Effective diffusion rates for 40 to 200 ka are relatively constant, on the order of 1 x 10-8 m2 yr-1. Our results suggests that the diffusion of sulfate ions within volcanic peaks is relatively fast initially, perhaps through the inter-connected vein network, but slows significantly after 40 kyr. In the absence of clear evidence for a controlling environmental factor on sulfate diffusivity with depth/age, we hypothesize that the rapid decrease in diffusion rate from the time of deposition to ice of 50 ka age may be due to a switch in the mechanism of diffusion resulting from the changing location of sulfate ions within the ice microstructure. [ABSTRACT FROM AUTHOR]

Aim: Genetic diversity driven by natural selection contributes to population divergence in amphibians, thus facilitating local adaptation to climate change. Understanding the mechanisms of genetic adaptation is one of the important issues in evolutionary biology. This study set out to reveal drivers responsible for intraspecific divergence in Fejervarya multistriata and further investigate the potential involvement of selected genes in responding to climate challenges. Location: China. Method: To identify adaptive traits associated with climate change, we conducted genome RAD‐seq of 300 F. multistriata individuals from 15 locations across a bio‐geographical range with gradual climatic variation in China. Results: The results indicate a substantial genetic diversity among populations of F. multistriata and highlight specific genes and pathways that likely contribute to intraspecific divergence. The demographic history of F. multistriata can be traced back to the last interglacial period, during which elevated temperatures may have led to a significant decline in effective population size. The analysis of genome‐climate association identified five candidate genes (BMP2K, NRAP, ZW10, MYH1 and PLB1) potentially involved in local climate adaptation. Main Conclusions: Our findings have shed light on the genetic mechanisms of local adaptation to climate change in F. multistriata, thereby aiding in determining the possible fate of populations under future climate change. [ABSTRACT FROM AUTHOR]