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The Black-throated Gray Warbler (Setophaga nigrescens) is a migratory songbird with a widespread and continuous distribution in the North American West. Previously published morphological data support the designation of 2 putative subspecies based on subtle differences in plumage and song; however, whether these patterns are clinal or discrete has yet to be determined. Furthermore, given that patterns of morphological variation occur across multiple distinct habitats and geographical boundaries, underlying population genetic structure may be present. To investigate this question and explore the evolutionary history of S. nigrescens, we conducted the first range-wide phylogeographic analysis of this species using genetic (mitochondrial DNA [mtDNA], ND2 gene sequences), morphological (body measurements), and environmental (niche modeling) data. Overall, our results identified 2 major mtDNA clades. One clade occurs east of the Cascade-Sierra ranges throughout the southwestern, Great Basin, and Rocky Mountain regions in North America (Interior clade), while a second widespread clade is comprised of birds that span the Pacific Northwest, and also across the Great Basin and southwest into the Rocky Mountains (Coastal clade). Divergence time estimates suggest a Pleistocene epoch vicariance event. Environmental niche models predict habitat modification and fragmentation from glacial-interglacial cycles, which were frequent over the Pleistocene. Range expansion northwards following the Last Glacial Maximum was identified from neutrality tests and shifts in suitable habitat from the Mid-Holocene to present-day conditions, where both clades arc likely experiencing secondary contact. We found support for nonequivalent environmental niches among both clades based on a spatial analysis of environmental variables, with the Coastal clade showing greater tolerance to both temperate and xeric climatic conditions across the North American West; however, the environmental space occupied by both clades was more similar to each other than expected by chance. High levels of geographic overlap and a lack of discrete patterns in morphology suggest few contemporary reproductive barriers to gene flow. Received 12 July 2023. Accepted 27 February 2024. Key words: gene tree, mitochondrial DNA, morphology, niche divergence, niche modeling, Pleistocene vicariance, subspecies delimitation. La reinita Setophaga nigrescens es un ave canora migratoria con una distribucion amplia y continua en el Oeste Norteamericano. Datos morfologicos previamente publicados apoyan la denominacion de 2 subespecies putativas basadas en diferencias sutiles en plumaje y canto; sin embargo, aun no se determina si esos patrones son cunales o discretos. Ademas, dado que los patrones de variacion morfologica ocurren en multiples habitats separados con limites geograficos definidos, podria estar presente una estructura poblacional genetica subyacente. Para estudiar esta pregunta y explorar la historia evolutiva de 5. nigrescens, condujimos el primer analisis filogenetico de todo el rango de distribucion de esta especie usando datos geneticos (ADN mitocondrial [mtDNA], secuencias geneticas ND2), morfologicos (medidas corporales) y ambientales (modelamiento de nicho). En general, nuestros resultados identificaron 2 ciados mayores de mtDNA. Un ciado se encuentra en las cordilleras Cascade-Sierra hacia el sudoeste y las regiones de Great Bassin y Rocky Mountain en Norte America (ciado Interior), mientras que un segundo ciado se compone de aves que se enceuntran en el Pacifico noroeste, ademas de a traves del Great Bassin y el sudoeste de las Rocky Mountains (ciado Costero). Los tiempos de divergencias estimados sugieren un evento de vicarianza en la epoca del Pleistoceno. Modelos de nicho ambiental predicen una modificacion y fragmentacion del habitat durante ciclos interglaciales, que eran frecuentes en el Pleistoceno. Una expansion de rango hacia el norte a partir del Ultimo Maximo Glacial frie identificada de pruebas de neutralidad y cambios de habitat favorables de condiciones del Holoceno medio a las actuales, donde ambos ciados posiblemente experimentaron contacto secundario. Encontramos apoyo para nichos ambientales no equivalentes entre ambos ciados basados en el analisis especial de variables ambientales, donde el ciado Costero mostro mayor tolerancia tanto a temperatura como a condiciones climaticas xericas a traves del Oeste Norteamericano; sin embargo, el espacio ambiental ocupado por ambos ciados era mas similar entre ellos que lo esperado por el azar. Altos niveles de sobrelapamiento geografico y una falta de patrones discretos morfologicos sugieren pocas barreras reproductivas contemporaneas al flujo genico. Palabras clave: ADN mitocondrial, arbol genetico, delimitacion de subespecies, divergencia de nicho, modelamiento de nicho, morfologia, vicarianza en el Pleistoceno., Evolutionary biologists have long been interested in investigating how historical and contemporary processes have influenced patterns of biodiversity across the globe. In particular, the historical events associated with Pleistocene glaciations [...]

Marine life on Earth is known back to the Archean Eon, when life on land is assumed to have been less pervasive than now. Precambrian life on land can now be tested with stable isotopes because living soil CO2 is isotopically distinct for both carbon and oxygen from both marine and volcanic CO2. Our novel compilation of previously published oxygen and carbon isotopic compositions of pedogenic and paleokarst carbonate can be compared with the coeval marine record. Long-term enrichment (to heavier isotopic composition) of oxygen, but no significant trend in carbon through time, long apparent from marine carbonate, is now demonstrated also for pedogenic and paleokarst carbonate. Oxygen isotopic enrichment is not due to changing global temperature or hypsometry, but to increased evapotranspiration and photosynthesis on larger continents. Differences in isotopic composition between land and sea have increased in an episodic fashion, peaking at times of major evolutionary innovations for life on land, and also at times of ice ages. The δ13C and δ18O divergences between land and sea correspond to terrestrial productivity spikes including evolution of Neoproterozoic (635 Ma) lichens, middle Ordovician (470 Ma) non-vascular land plants, middle Devonian (385 Ma) forests, early Cretaceous (125 Ma) angiosperms, and middle Miocene (20 Ma) sod grasslands. [ABSTRACT FROM AUTHOR]

Planet formation is strongly influenced by the composition and distribution of volatiles within protoplanetary disks. With JWST, it is now possible to obtain direct observational constraints on disk ices, as recently demonstrated by the detection of ice absorption features toward the edge-on HH 48 NE disk as part of the Ice Age Early Release Science program. Here, we introduce a new radiative transfer modeling framework designed to retrieve the composition and mixing status of disk ices using their band profiles, and apply it to interpret the H2O, CO2, and CO ice bands observed toward the HH 48 NE disk. We show that the ices are largely present as mixtures, with strong evidence for CO trapping in both H2O and CO2 ice. The HH 48 NE disk ice composition (pure versus polar versus apolar fractions) is markedly different from earlier protostellar stages, implying thermal and/or chemical reprocessing during the formation or evolution of the disk. We infer low ice-phase C/O ratios around 0.1 throughout the disk, and also demonstrate that the mixing and entrapment of disk ices can dramatically affect the radial dependence of the C/O ratio. It is therefore imperative that realistic disk ice compositions are considered when comparing planetary compositions with potential formation scenarios, which will fortunately be possible for an increasing number of disks with JWST. [ABSTRACT FROM AUTHOR]

Basins within cratonic environments offer valuable insights into the fragmentation, dispersion, and agglutination of the lithosphere within supercontinents. The southern São Francisco Craton is home to sedimentary basins that formed in both intraplate tectonic settings (late Paleoproterozoic to Neoproterozoic and Mesozoic) and convergent tectonic settings (Ediacaran to Cambrian). To elucidate the Phanerozoic thermal history of the craton and the long-term depositional history of the southern São Francisco Craton's cover, a comprehensive study was conducted utilizing detrital zircons through zircon fissiontrack (ZFT) thermochronology and U-Pb-Hf geochronology. This study analyzed samples from the following units: (1) the intracratonic basin--Lower and Upper Espinhaço Supergroup, with depositional age intervals ranging 1800-1600 Ma and 1200-920 Ma, respectively; (2) the rift-related passive margin basin--Lower Macaúbas Group (720 Ma and 640 Ma) and Jequitaí Formation, which is likely of Cryogenian age (650-635 Ma); (3) and the foreland basin--Bambui Group and Três Marias Formation, with ages of ca. 600-520 Ma and 520-480 Ma, respectively. U-Pb-Hf detrital zircon geochronology revealed the complex depositional history of the southern São Francisco Craton, and indicated changing source rocks over time. Conversely, the ZFT analysis of Precambrian to Cambrian samples allowed for the identification and characterization of Phanerozoic events in the southern São Francisco Craton. These events include: (1) the exhumation and late orogenic uplift of the foreland at ca. 500-480 Ma (mean age of 499 ± 5.5 Ma) during the late stages of the Brasiliano-Pan-African Cycle, which was associated with the Araçuaí Belt and lithospheric rebound of the peripheral cratonic margin of the southern São Francisco Craton; and (2) an age of 330-280 Ma (mean age of 306.6 ± 4.8 Ma) that possibly resulted from ice retreat and isostatic rebound interior of the Gondwana Paleocontinent. Additionally, analysis of detrital zircons from the Areado Group shows a later tectonic event recorded at 128.1 ± 9.4 Ma, which indicates Mesozoic intracontinental rifting. Based on these results and interpretations, the timing and exhumation of the southern São Francisco Craton during the Phanerozoic can be attributed to the final stages of the continental collision of the southern São Francisco Craton and Congo Craton and large-scale continental uplift during the Permo-Carboniferous late Paleozoic Ice Age of Gondwana. Overall, the findings demonstrate a direct correlation between known tectonic events at the plate margins of Western Gondwana and periods of cratonic basin formation. [ABSTRACT FROM AUTHOR]

The early Paleoproterozoic (ca. 2.5–2.2 Ga) represents a critical juncture in Earth history, marking the inception of an oxygenated atmosphere while bearing witness to potentially multiple widespread and severe glaciations. Deciphering the nature of this glacial epoch and its connection with atmospheric oxygenation has, however, proven difficult, hindered by a reliance on disputed stratigraphic correlations given the paucity of direct radiometric age constraints. Nowhere is this more acute than within the South African Transvaal Supergroup: Here, while the loss of oxygen-sensitive mass-independent sulfur isotope fractionation (S-MIF) has been reported from both the Duitschland and Rooihoogte formations, divided opinion surrounding the time-equivalence of these units has prompted authors to argue for vastly different oxygenation trajectories. Addressing this debate, we present a depositional Re-Os age (2443 ± 33 Ma) from diamictite samples preserved in drillcore of the upper Duitschland Formation. The 100-million-year separation between the Duitschland Formation and its previously presumed equivalent reveals at least two isolated disappearances of S-MIF, requiring that the Great Oxidation Event was dynamic and proceeded via discrete oxygenation episodes whose structure remains incompletely understood. Importantly, our revised framework aligns the lower Duitschland diamictite with the low-latitude glacigenic Makganyene Formation, supporting hypotheses of widespread regional, and potentially global, early Paleoproterozoic glaciation. [ABSTRACT FROM AUTHOR]

• Refugia or refuges are a concept that can contribute to an understanding of survival in the Anthropocene at different levels of abstraction. • Urban green spaces are areas where interactions between human and non-human nature can occur. They serve as refuges in the city and can be beneficial for both biodiversity and human well-being. • Over 70 % of the reviewed studies report positive effects of unmown refuges on arthropod abundance and richness in meadows or green spaces. • Unmown refuges allow habitat heterogeneity, a shelter for surviving arthropods from mowing, a chance for larval development, and a place to hibernate. Large refugia and small refuges have always been crucial for species survival, particularly during periods like the Ice Age. When their original habitats became uninhabitable, they provided important shelters in space and time. Drawing from a biological and philosophical perspective, we propose creating and preserving refuges as socio-ecological solutions in an epoch primarily shaped by human activity, the Anthropocene. Our focus lies on green refuges within urban settings, given that urbanization is one of the large drivers of insect decline and has adverse effects on humans, such as increased heat. Refuges can be beneficial for both biodiversity and human well-being. After clarifying the relevant terminology on four levels of abstraction, we conducted a systematic biological literature review - as a case study. Here, we summarize the current state of research on the effects of unmown refuges on insects and spiders. The mere existence of refuges proved beneficial for arthropods, with over 70 % of studies reporting positive responses among these species. While insects and spiders have specific habitat requirements, humans are able to create a habitable environment for themselves. However, ecological crises for humans and arthropods are increasing, as are human populations. Therefore, refuges offer a way to address both ecological and social challenges simultaneously, enhancing biodiversity and human well-being. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper investigates the causes and the consequences of the emergence of agriculture in the Middle East. Agriculture has emerged in many parts of the world since the end of the last Ice Age about 15 000 years ago. The paper first surveys the Palaeolithic Period to understand why agriculture did not emerge earlier. Then the paper considers the processes that led to the emergence of agriculture in the Middle East. The question is approached as a problem in economic history, and the archaeological record is understood in terms of changes in labour productivity, as measured by calories produced per hour of work, and in the size of the associated agricultural surplus (the difference between the calories produced by a food procurement system and the calories required to sustain the people trying to support themselves with that system). The shift from foraging to the cultivation of wild seeds and the later impact of the emergence of domestic seed and improvements in tool design are assessed in this framework. It is also used to analyse the impact of agriculture on human wellbeing, the origin of manufacturing (e.g. pottery), and the emergence of inequality, states, and warfare. [ABSTRACT FROM AUTHOR]

Glacial movements shaped vast northern parts, offering critical insights into glacial dynamics in a changing climate. Located on the island of Rügen in NE Germany, the Jasmund Glacitectonic Complex (JGC) is a key area to study the dynamics of past glaciations. Previous reconstructions focused primarily on the onshore realm, resulting in some areas remaining unexplored. Here we use more than 140 high‐resolution marine multi‐channel seismic profiles to map the erosional unconformity surrounding the JGC for the first time. Submarine glacial features match features observed onshore, allowing a consistent land‐to‐sea reconstruction of the evolution of the JGC. Our results indicate a single SW‐directed Weichselian glacier advance, suggesting that the JGC formed through three distinct glacier lobes exerting pressure from multiple directions. The ice advance encircled the Jasmund peninsula and overthrusted Cretaceous sediments on the JGC perpendicularly and laterally. Plain Language Summary: The Jasmund Glacitectonic Complex on Rügen island, northeast Germany, is a popular tourist destination and a key area for studying how deformations and erosion by former ice sheets shape our landscapes. Previous studies were limited to the onshore area and suggested that the complex formed in three separate phases. Our study uses marine seismic imaging techniques that suggest an alternative development. By creating detailed maps of the proposed glacial erosional surface from seismic data, we discovered depressions of different shapes that were carved by glaciers moving southwestwards during the last ice age. The erosional feature is 100 m deep and matches earlier predictions of the ground's response to glacial movement. The mapping indicates that the glacial traces on the seabed extend onto the land. We propose that a single glacier movement was responsible for shaping the entire area in one dynamic phase. This shows that the sediments were compressed and displaced in varying directions during the ongoing (single) ice advance. Key Points: Seismic mapping, offshore channels and depressions, thrust‐fault structures, ice advance dynamics, Jasmund Glacitectonic Complex, Rügen Island and surrounding Baltic Sea, NE Germany [ABSTRACT FROM AUTHOR]

Genetic diversity is heterogeneously distributed among populations of the same species, due to the joint effects of multiple demographic processes, including range contractions and expansions, and mating systems shifts. Here, we ask how both processes shape genomic diversity in space and time in the classical Primula vulgaris model. This perennial herb originated in the Caucasus region and was hypothesized to have expanded westward following glacial retreat in the Quaternary. Moreover, this species is a long-standing model for mating system transitions, exemplified by shifts from heterostyly to homostyly. Leveraging a high-quality reference genome of the closely related Primula veris and whole-genome resequencing data from both heterostylous and homostylous individuals from populations encompassing a wide distribution of P. vulgaris , we reconstructed the demographic history of P. vulgaris. Results are compatible with the previously proposed hypothesis of range expansion from the Caucasus region approximately 79,000 years ago and suggest later shifts to homostyly following rather than preceding postglacial colonization of England. Furthermore, in accordance with population genetic theoretical predictions, both processes are associated with reduced genetic diversity, increased linkage disequilibrium, and reduced efficacy of purifying selection. A novel result concerns the contrasting effects of range expansion versus shift to homostyly on transposable elements, for the former, process is associated with changes in transposable element genomic content, while the latter is not. Jointly, our results elucidate how the interactions among range expansion, transitions to selfing, and Quaternary climatic oscillations shape plant evolution. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive palaeoenvironmental reconstruction of the southern part of the Danube–Tisza interfluve in the Carpathian Basin from the Late Pleistocene to Early Holocene, addressing the region's response to global climate forcings and local environmental factors based on multi-proxy analyses of two key protected areas: the Katymár brickyard and the hay meadows and loess banks of Hajós. By integrating radiocarbon-dated malacological, macrobotanical, pollen, phytolith, geochemical, and sedimentological analyses, it was possible to provide a picture of past climate–ecosystem interactions. The Katymár North sequence provides an extended chronology from Marine Isotope Stage 3 (MIS3, ca. 36,000 cal BP) through the Last Glacial Maximum (LGM) and into the Early Holocene, while the Hajós sequence offers high-resolution data for the LGM–Holocene transition. By the late Ice Age, humidity and surface moisture superseded temperature as primary palaeoecological limiting factors, promoting ecotone-like forest–steppe environments during cooling periods. [ABSTRACT FROM AUTHOR]

The first data on the population genetic structure of the Daphnia cristata Sars, 1862 and D. longiremis Sars, 1862 species (Anomopoda: Daphniidae) from the water bodies of Northern Eurasia are presented. The variability of the fragment of the 12S gene of the mtDNA for these taxa belonging to subgenus Daphnia (Daphnia) O.F. Müller, 1776 (Crustacea: Cladocera) in this region is studied, and a phylogenetic analysis performed. The genealogical relationships between haplotypes of the Daphnia cristata and D. longiremis species and their geographical distribution are shown. Our new data allow us to suggest a recent rapid spatial expansion for D. cristata during the Late Pleistocene and Early–Middle Holocene periods. According to the results of the study, the distribution of D. cristata and D. longiremis species are separated in the latitudinal direction with the zone of their contact in Central Yakutia. Our results provide convincing evidence for the influence of the Ice Ages and interglacials on the formation of modern genetic diversity and the phylogeographic structure of D. cristata and D. longiremis. [ABSTRACT FROM AUTHOR]

Blue holes are vertical water‐filled openings in carbonate rock that exhibit complex morphology, ecology, and water chemistry. In this study, macroscopic microbial mat structures found in complete anoxic conditions in the Faanu Mudugau Blue Hole (Maldives) were studied by metagenomic methods. Such communities have likely been evolutionary isolated from the surrounding marine environment for more than 10,000 years since the Blue Hole formation during the last Ice Age. A total of 48 high‐quality metagenome‐assembled genomes (MAGs) were recovered, predominantly composed of the phyla Chloroflexota, Proteobacteria and Desulfobacterota. None of these MAGs have been classified to species level (<95% ANI), suggesting the discovery of several new microbial taxa. In particular, MAGs belonging to novel bacterial genera within the order Dehalococcoidales accounted for 20% of the macroscopic mat community. Genome‐resolved metabolic analysis of this dominant microbial fraction revealed a mixotrophic lifestyle based on energy conservation via fermentation, hydrogen metabolism and anaerobic CO2 fixation through the Wood–Ljungdahl pathway. Interestingly, these bacteria showed a high proportion of ancestral genes in their genomes providing intriguing perspectives on mechanisms driving microbial evolution in this peculiar environment. Overall, our results provide new knowledge for understanding microbial life under extreme conditions in blue hole environments. [ABSTRACT FROM AUTHOR]

Maps of diluvial boundaries for the North American midcontinent are presented by state and by sedimentary basin. The upper diluvial boundary is the base of Ice Age sediments. For most of the study area, the basal diluvial boundary is the erosional unconformity between Precambrian crystalline rock and the Phanerozoic sedimentary record. The exceptions are Proterozoic to Cambrian rifts: the Midcontinent, East Continent, Fort Wayne, Reelfoot, Rough Creek Graben, and Rome Trough rifts. These are remnants of severe crustal disruption at the onset of the Flood, with varying ratios of volcanic and sedimentary fill. This paper focuses on the basal marine diluvial boundary and the upper diluvial boundary, excluding the rifts, showing the volume and distribution of sediments of the Ice Age. Deep Proterozoic rifts will be addressed in Part II. Detailed state maps of the basal diluvial boundary are shown in the appendix. Maps of the study area reveal cratonic basins of varying size, show a thickening of diluvial strata toward the south, and show the extent of Ice Age deposition. All these aid in understanding the work of the Flood in this region. [ABSTRACT FROM AUTHOR]

The purpose of the study is to compare the results of the stable isotope analysis (δ18O, δ2H, and deuterium excess values) of parallel and synchronous ice wedges exposed in one outcrop in the upper part of the Batagay Yedoma (67.58° N, 134.77° E) and to estimate their precision, that is, a measure of similarity of independent isotope results of two ice wedges. Detailed sampling of two syngenetic ice wedges (IW‐17 and IW‐20) for isotope analysis was carried out in the exposure of the thermo‐erosional ravine in the southeastern part of the Batagay megaslump. In total, results of 105 measurements for IW‐17 and 59 measurements for IW‐20 were obtained. According to 14C AMS ages of organic microinclusions in the ice‐wedge ice, the studied ice wedges began to form no later than 42 cal ka BP. The termination of their growth was dated to about 11.7 cal ka BP. For both ice wedges, generally low isotope values were obtained. For the IW‐17, the mean values are −34.38‰ for δ18O, −264.82‰ for δ2H, and 10.2‰ for dexc. For IW‐20, the mean isotope values are −34.09‰ for δ18O, −262.91‰ for δ2H, and 9.84‰ for dexc. Statistical tests showed significant correlations between the isotope data in the upper parts of ice wedges that may be explained by similar conditions during their growth at this stage. Our results allow us to refine the solutions to the two main issues studied of the Late Pleistocene Yedoma: the age of the ice wedges, the accuracy of the isotope profiles, and the paleotemperature interpretation of the isotope records. [ABSTRACT FROM AUTHOR]

The Antinaco‐Los Colorados valley (ALCV) is a tectonic depression located in the centre‐north of the province of La Rioja (Argentina), limited to both the east and west by mountain ranges, in the broken foreland region. Geomorphological research on environmental dynamics is important for both building a reference framework for further studies and for the development of the socio‐economic activities in the area. This study presents the main geomorphological features of the tectonic depression at the regional scale in order to identify the primary factors involved in its evolution and the landforms it contains. The ALCV is asymmetric, and it is filled by up to 1600 m of sediments along the western margin. Using literature, images, digital elevation models of the study area and field work, different morphologies were identified in the valley, mostly linked to Quaternary climatic and tectonic changes. These morphologies were grouped into three main morphogenetic units that characterize this landscape: the relict piedmont levels, the current piedmont and the fluvial‐aeolian plain. The identification of fluvial forms suggests that fluvial systems have been important during the evolution of the landscape. Aeolian accumulation features, currently mostly vegetated, were likely formed under drier climatic conditions than those at present and probably related to the last ice age or even more recent times. Successive reactivations of the overall system are not only tectonic, as evidenced by the structural lineaments that affect relict piedmont levels and the fluvial‐aeolian plain, but also climatic. Thus, the identified landforms suggest that climatic and tectonic variables account for the variations in the environment of the ALCV, affecting the reaccommodation of the exogenous geomorphological processes and the modelling of the relief. [ABSTRACT FROM AUTHOR]

The interplay between geographic barriers and climatic oscillations over the past 2.6 million years structured genetic variation at the continental scale. The genetic legacy of the Quaternary ice ages (GLQ) hypothesis outlines this phenomenon for Europe, but a comprehensive data-driven assessment is lacking. Using innovative genetic landscape methods, we model the GLQ in the West Palearctic based on 31,653 Cytochrome c oxidase subunit 1 (COI) sequences from 494 butterfly species and three functional traits. Seven distinct bioregions with varying levels of genetic endemicity emerge, revealing a latitudinal gradient in variation that confirms the "southern richness, northern purity" hypothesis. Through shift from case studies to a comparative approach, we objectively identify the main glacial refugia, colonization routes, and barriers to dispersal. Our findings offer a quantitative model of the GLQ across Europe, North Africa, and neighboring Asia, with broader applicability to other taxa and potentially scalable to encompass life on Earth. [ABSTRACT FROM AUTHOR]

Antifreeze proteins (AFPs) are found in a variety of marine cold‐water fishes where they prevent freezing by binding to nascent ice crystals. Their diversity (types I, II, III and antifreeze glycoproteins), as well as their scattered taxonomic distribution hint at their complex evolutionary history. In particular, type I AFPs appear to have arisen in response to the Late Cenozoic Ice Age that began ~ 34 million years ago via convergence in four different groups of fish that diverged from lineages lacking this AFP. The progenitor of the alanine‐rich α‐helical type I AFPs of sculpins has now been identified as lunapark, an integral membrane protein of the endoplasmic reticulum. Following gene duplication and loss of all but three of the 15 exons, the final exon, which encoded a glutamate‐ and glutamine‐rich segment, was converted to an alanine‐rich sequence by a combination of frameshifting and mutation. Subsequent gene duplications produced numerous isoforms falling into four distinct groups. The origin of the flounder type I AFP is quite different. Here, a small segment from the original antiviral protein gene was amplified and the rest of the coding sequence was lost, while the gene structure was largely retained. The independent origins of type I AFPs with up to 83% sequence identity in flounder and sculpin demonstrate strong convergent selection at the level of protein sequence for alanine‐rich single alpha helices that bind to ice. Recent acquisition of these AFPs has allowed sculpins to occupy icy seawater niches with reduced competition and predation from other teleost species. [ABSTRACT FROM AUTHOR]

Summary Early studies of the textbook mixed‐ploidy system Biscutella laevigata highlighted diploids restricted to never‐glaciated lowlands and tetraploids at high elevations across the European Alps, promoting the hypothesis that whole‐genome duplication (WGD) is advantageous under environmental changes. Here we addressed long‐held hypotheses on the role of hybridisation at the origin of the tetraploids, their single vs multiple origins, and whether a shift in climatic niche accompanied WGD. Climatic niche modelling together with spatial genetics and coalescent modelling based on ddRAD‐seq genotyping of 17 diploid and 19 tetraploid populations was used to revisit the evolution of this species complex in space and time. Diploids differentiated into four genetic lineages corresponding to allopatric glacial refugia at the onset of the last ice age, whereas tetraploids displaying tetrasomic inheritance formed a uniform group that originated from southern diploids before the last glacial maximum. Derived from diploids occurring at high elevation, autotetraploids likely inherited their adaptation to high elevation rather than having evolved it through or after WGD. They further presented considerable postglacial expansion across the Alps and underwent admixture with diploids. Although the underpinnings of the successful expansion of autotetraploids remain elusive, differentiation in B. laevigata was chiefly driven by the glacial history of the Alps. [ABSTRACT FROM AUTHOR]

Applying BEAST v1.10.4, we constructed a Bayesian Inference tree comprising 322 taxa, primarily representing Paleoptera (Odonata and Ephemeroptera; Pterygota), Zygentoma and Archaeognatha (Apterygota; paraphyly), and Neoptera (Plecoptera; Pterygota), based on a 2685 bp sequence dataset. Our analyses revealed that robust dating required the incorporation of both Quaternary and pre‐Quaternary dates. To achieve this, our dating incorporated a 1.55 Ma (Quaternary) geological event (the formation of the Ryukyu Islands) and a set of chronologically well‐founded fossil dates, spanning from up to 400 Ma (Devonian) for the stem Archaeognatha, 320 Ma (Carboniferous) for the crown of Paleoptera, 300 Ma (Carboniferous) for the crown Ephemeroptera, and 280 Ma (Permian) for the crown Odonata, down to 1.76 Ma (Quaternary) for Calopteryx japonica, encompassing a total of 22 calibration points (events: 6, fossils: 16; Quaternary: 7, pre‐Quaternary: 15). The resulting dated tree aligns with previous research, albeit with some dates being overestimated. This overestimation was mainly due to the lack of Quaternary calibration and the exclusive dependence on pre‐Quaternary calibration, though the application of maximum age constraints also played a role. Our minimum age dating demonstrates that the molecular clock did not uniformly progress, rendering rate dating an inapplicable approach. We observed that the base substitution rate is time‐dependent, with an exponential increase evident from around 20 Ma (Miocene) to the present time, exceeding an order of magnitude. The extensive radiation and speciation of Insecta and Paleoptera, potentially resulting from the severe climatic changes associated with the Quaternary, including the commencement of glacial and interglacial cycles, may have significantly contributed to this increase in base substitution rates. Additionally, we identified a potential peak in base substitution rates during the Carboniferous period, around 320 million years ago, possibly corresponding to the Late Paleozoic Ice Age. [ABSTRACT FROM AUTHOR]

The Cryogenian (ca. 717–635 Ma) snowball Earth glaciations ended with the precipitation of “cap” carbonate successions with negative carbon isotope (δ13Ccarb) values, which have been explained by the addition of various 13C-depleted carbon sources in the deglacial process. These arguments assumed that marine dissolved inorganic carbon (DIC) was enriched in 13C in the synglacial ocean. However, this assumption has not yet been tested, because the synglacial ocean chemistry is unknown. In this study, we carried out detailed analyses of the petrology, carbonate carbon (δ13Ccarb) and oxygen (δ18Ocarb) isotopes, organic carbon (δ13Corg) isotopes, major and minor elemental compositions (Ca, Mg, Mn, Fe, Sr), and iron speciation (total Fe, highly reactive Fe, pyrite Fe) of the carbonate layers (also called synglacial carbonate layers) from the Nantuo Formation (ca. 650–635 Ma) on the Yangtze block, South China. Petrographic observations indicated that the synglacial carbonate comprises dolomicrite, mud-crystal powder dolomite, lime dolomite, and dolomitic limestone, supporting an authigenic carbonate origin, and thus, it potentially recorded the ocean chemistry during the Marinoan ice age. The synglacial carbonate is characterized by extreme Mn enrichment, low Fe/Mn ratios, and low δ13Ccarb (−7‰) values. High Mn contents and low Fe/Mn ratios imply marine redox conditions favoring Mn2+ accumulation and Fe2+ oxidation, while low δ13Ccarb values might be attributed to CO2 degassing of submarine volcanoes as well as low primary burial during the glaciation. Since the δ13CDIC value of the synglacial ocean was lower than the δ13Ccarb values of most cap carbonates, we infer the addition of 13C-enriched DIC or removal of 12C during cap carbonate precipitation, such as through carbonate weathering or organic carbon burial. These findings provide new insights into the nature of Cryogenian glaciation, the origin of cap carbonates, and the aftermath of global glaciation [ABSTRACT FROM AUTHOR]

The closure of the Paleo-Asian Ocean was a significant geological event in northern Pangea during the Carboniferous-Permian. It had a significant effect on climate, biota, and environmental conditions of the Late Paleozoic Ice Age, and resulted in the development of vast energy resources. This paper reports on the first discovery of marine red algal fossils in the Junggar Basin and its linkage to hydrocarbon generation. Red algae occur mainly in the Fengcheng Formation (ca. 300 Ma) and provide direct fossil evidence for closure of the Paleo-Asian Ocean. The red algal fossils contain well-preserved reproductive organs, such as cystocarps and carpospores. High concentrations of C27 steranes (C27 regular steranes/sum of C27–C29 regular steranes×100=14.30%–21.30%) and the marine biomarker 24-n-propylcholesterane (C30 diasterane [βα20S]/sum of C27–C30 diasteranes [βα20S]×100=1.15%–1.85%) were detected in the red-algae-bearing hydrocarbon source rocks. Thermal experiments that simulate hydrocarbon generation show that the oil generation potential of the red-algae-bearing source rocks is 363.71 mg g−1 total organic C. This result, combined with oil-source rock correlations, indicates these rocks contributed to the formation of oil and gas resources, particularly in the marginal areas of the depression. The lake basin inherited the water and biological conditions of the Paleo-Asian Ocean during a marine regression, which was an important factor in the development of these high-quality hydrocarbon source rocks in an alkaline saline lake. The results advance our understanding of the evolution of the Paleo-Asian Ocean, interactions between the ocean and a lake during the deposition of terrestrial hydrocarbon source rocks, and whether red algae can effectively generate hydrocarbons. [ABSTRACT FROM AUTHOR]

In addition to natural curiosity, science is characterized by a number of psychological processes and perceptions. Among the psychological features, scientific enquiry relates to uncovering—or discovering—aspects of a world perceived as hidden from humans. A speculative theoretical model is presented, suggesting the evolution of science reflects psychological repercussions of wearing clothes. Specifically, the natural world is perceived as hidden due to the presence of clothing. Three components of scientific enquiry may arise from clothing: detachment from sensual experience, a perception that the world is veiled in mystery, and an intellectual desire to uncover the hidden structure of nature. Rather than beginning with the emergence of Homo sapiens, the proposed connection with clothing implies that psychological foundations for science began to develop during the last ice age, with the invention of complex clothes that fully covered the human body. After the end of the last ice age, elements of scientific thinking began to emerge in societies where clothing was worn routinely for psychosocial reasons, including modesty. Notably, a scientific attitude was essentially absent in hunter-gatherer communities where nakedness remained the norm. This novel perspective aims to advance the history and philosophy of science, revealing the emergence of science as a situated phenomenon contingent on humans being covered. [ABSTRACT FROM AUTHOR]

Low sea levels during the last Ice Age exposed millions of square kilometers of Arctic shelves which have been subsequently submerged, creating subsea permafrost. In onshore settings, permafrost can also exist beneath water bodies such as coastal lagoons, rivers, and thermokarst lakes. We explored passive seismology as a method for mapping unfrozen sediment thickness above subsea and sub‐aquatic permafrost. We present passive seismic data collected with the Mobile Ocean Bottom Seismic Instrument (MOBSI) from the Beaufort Sea near Tuktoyaktuk in Canada, Ivashkina Lagoon on the Bykovsky Peninsula, as well as a lake and river in the Lena Delta, Siberia, Russia. We use borehole data and frost probe measurements to identify permafrost‐related H/V measurement peaks and calibrate shear wave velocities for frequency‐to‐depth conversion. We employ the shortest path and maximum signal amplitude to connect peaks and generate geological profiles. The MOBSI detected the ice‐bonded permafrost table beneath the Beaufort Sea, as well as beneath a Siberian lake and lagoon. At Tuktoyaktuk, an ocean bottom seismometer revealed a 5% scatter about the peak frequency for three‐minute time windows and over 8 hr of recording time. With peak frequencies ranging from 4.9 ± 0.2 Hz to 27.6 ± 1.4 Hz, the depth to subsea permafrost ranged from 1.4 ± 0.1 m bsl at the shoreline to 14.0 ± 0.4 m bsl 240 m offshore. Given an accurate shear wave velocity, our findings highlight that MOBSI deployment times as short as 3 min are adequate for detecting Arctic subsea and sub‐aquatic permafrost. Plain Language Summary: During the Ice Age, low sea levels exposed large areas of the Arctic, creating perennially frozen ground known as permafrost. When sea levels rose, this permafrost became submerged. Permafrost can also exist under bodies of water like coastal lagoons, rivers, and lakes. However, we have limited direct measurements of its characteristics and how it is changing over time. To address this, we used a technique called passive seismology to map the thickness of unfrozen sediment above subsea and sub‐aquatic permafrost. We collected passive seismic data using the Mobile Ocean Bottom Seismic Instrument (MOBSI) in the Beaufort Sea near Tuktoyaktuk in Canada, Ivashkina Lagoon on the Bykovsky Peninsula, and a lake and river in the Lena Delta, Siberia, Russia. This method involves recording ambient seismic noise to identify differences in the speed of shear waves in the subsurface. These boundaries with contrasting velocities are associated with geological interfaces like the top of permafrost. We used data from boreholes and frost probe measurements to calibrate and verify our passive seismic results. Key Points: We present passive seismic data from Arctic lake, river, lagoon, and subsea permafrost settingsWe applied the maximum H/V amplitude and shortest path to connect H/V peaks and interpret subsurface shear wave velocity contrastsPassive seismic H/V ratio measurements of just a few minutes of recording time can be used to investigate the depth of submerged permafrost [ABSTRACT FROM AUTHOR]

Eucommia ulmoides (EU) is a precious tree species native to China originating during the ice age. This species has important economic value and comprehensive development potential, particularly in medicinal applications. The medicinal parts of EU are its bark (Eucommiae cortex) and leaves (Eucommiae folium) which have been successively used as a traditional Chinese medicine to treat diseases since the first century BC. During the last 2 decades, as natural polysaccharides have become of increasing interest in pharmacology, biomedicine, cosmetic and food applications, more and more scholars have begun to study polysaccharides derived from EU as well. EU polysaccharides have been found to have a variety of biological functions both in vivo and in vitro, including immunomodulatory, antioxidant, anti-inflammatory, anticomplementary, antifatigue, and hepatoprotective activities. This review aims to summarize these recent advances in extraction, purification, structural characteristics, pharmacological activities and applications in different fields of EU bark and leaf polysaccharides. It was found that both Eucommiae folium polysaccharides and Eucommiae cortex polysaccharides were suitable for medicinal use. Eucommiae folium may potentially be used to substitute for Eucommiae cortex in terms of immunomodulation and antioxidant activities. This study serves as a valuable reference for improving the comprehensive utilization of EU polysaccharides and further promoting the application of EU polysaccharides. [ABSTRACT FROM AUTHOR]

The end of the Neoproterozoic global ice age has promoted the evolution of the Earth's surface system and initiated the 'Great Explosion of Life'. Glaciation deposits provide valuable insights into the extreme climate conditions. In the southern margin of the North China Craton (NCC), an Ediacaran glacial deposit named 'Luoquan Formation' has been recently described in Luonan County, Shaanxi Province. It has significant characteristics of dark grey and black glacial deposits. Through extensive research in sedimentology, geochemistry and geochronology, the glacial sedimentary evolution sequence of the Luoquan Formation has been established. This research also help to define the age of the formation and reveal its provenance and sedimentary environment. The study reveals that four lithofacies associations were identified in the Luoquan Formation: diamictites, carbonates, dropstone‐bearing rock and black shale. The Luoquan Formation has experienced three cycles of glacial advance–retreat. Sedimentological evidence suggests that the sedimentary environments of the Luoquan Formation evolved from subglacial (diamictite) to intertidal, then to intertidal lagoon, or from subglacial deposits to shoreface (inner shelf, subtidal), then to deep water basin and fine‐grained turbidite and ice‐rafting. The age of the Luoquan Formation is estimated to be 562–550 Ma constrained by indirect chronological and paleontological data, maybe representing an Upper Ediacaran glaciation that occurred later than the Gaskiers glaciation. The overall age profile of detrital zircons from the Luoquan Formation can be divided into six groups, ranging from 1.1 to 1.6, 1.85 to 1.95, ~2.1, ~2.3, ~2.5 and 2.65 to 2.9 Ga. These age groups are consistent with the Archean to Meso‐Neoproterozoic magmatic–tectonic events in the southern margin of NCC, indicating they are ascribed to an origination directly from the southern margin of NCC. The Luoquan Formation exhibits the characteristics of isochronous and different sedimentary facies, with the glacial front moving from north to south. The discovery of Luoquan Formation in Lianshuigou section not only reflects the important significance of the restoration and reconstruction of the Ediacaran ice age, paleoenvironment and palaeogeography of the NCC but also provides significant evidence to support the further subdivision and correlation within the Ediacaran glacial deposits globally. [ABSTRACT FROM AUTHOR]

The article focuses on the first documentation of Late Paleozoic conodonts from Argentina, which provides new biostratigraphic and paleoclimatic insights into the Late Paleozoic Ice Age in southwestern Gondwana. It details systematic paleontology, including the genus Neognathodus and its species, such as Neognathodus colombiensis and Neognathodus "pre-colombiensis," with emphasis on their evolutionary patterns and morphological variations.

A pre‐Late Wisconsinan, post‐Illinoian, till sheet has long been recognized in north‐central Iowa, but has not been formally recognized or defined until now. Early researchers referred to these deposits as the 'Tazewell', and the term 'Sheldon Creek' was more recently used informally by the Iowa Geological Survey in guidebooks and reports. Recent mapping has extended the eastern margin significantly past previous interpretations. The Sheldon Creek Formation has similar lithologic characteristics to the overlying Alden Member of the Dows Formation, and the two units are distinguished mainly by stratigraphic position. Differentiation from underlying Pre‐Illinoian till units is accomplished using lithology, primarily matrix grain‐size and sand fraction lithology. A suite of 22 radiocarbon ages indicate two distinct, separate groupings within the Sheldon Creek data. These data strongly suggest ice advanced south to 42° N twice, once during Marine Isotope Stage (MIS) 3 and again during late MIS 3 or possibly early MIS 2. The presence of the Laurentide Ice Sheet in northern Iowa during MIS 3 has significant implications for ice sheet reconstructions during this interval. [ABSTRACT FROM AUTHOR]

N2 fixation in low‐latitude surface waters dominates the input of fixed nitrogen (N) to the global ocean, sustaining ocean fertility. In the Caribbean Sea, higher foraminifera‐bound (FB‐)δ15N indicates a decline in N2 fixation during ice ages, but its cause and broader implications are unclear. Here, we report three additional Atlantic FB‐δ15N records, from the subtropical North and South Atlantic gyres (MSM58‐50 and DSDP Site 516) and the equatorial Atlantic (ODP Site 662). Similar glacial and interglacial δ15N in the equatorial Atlantic suggests a stable δ15N for the nitrate below the gyre thermoclines. The North Atlantic record shows a FB‐δ15N rise during the ice ages, resembling a previously published FB‐δ15N record from the South China Sea. The commonality among the FB‐δ15N records is that they resemble sea level‐driven variation in regional shelf area, with high FB‐δ15N (inferred reduction in N2 fixation) during periods of low shelf area. The South China Sea shows the largest δ15N signal, the subtropical North Atlantic shows less, and the South Atlantic shows the least, the same ordering as the ice age reductions in continental shelf area in the different regions. Reduced shelf sedimentary denitrification would have increased the nitrogen‐to‐phosphorus ratio of the nutrient supply to open ocean surface waters, leading to decreased N2 fixation and thus higher gyre thermocline nitrate δ15N, explaining the higher FB‐δ15N of peak ice ages. These observations identify shelf sediment denitrification as an important regional driver of modern N2 fixation and imply strong basin‐scale coupling of fixed nitrogen losses and inputs. Plain Language Summary: Nitrogen fixation plays the crucial role in the ocean of supplying bioavailable nitrogen (N), a major nutrient for phytoplankton growth. Variations in nitrogen fixation over time can, therefore, significantly impact ocean productivity and, consequently, carbon sequestration in the ocean interior. To infer past changes in nitrogen fixation during ice ages, we measured the nitrogen isotope (15N‐to‐14N) ratio of organic matter preserved within the carbonate skeleton of planktic foraminifera. Our study reveals a substantial reduction in nitrogen fixation during ice ages in the low‐nutrient regions of the North Atlantic, with only minor variations in the South Atlantic. The basin‐dependent changes are attributed to sea level‐driven reductions in regional continental shelf area during ice ages, resulting in diminished sedimentary denitrification and subsequently lower phosphorus excess in the surface waters downstream of the continental shelves. Overall, our study highlights the importance of regional factors, like shelf sediment denitrification, in influencing oceanic nitrogen fixation within a given ocean basin. Furthermore, it suggests that changes in nitrogen fixation cannot explain the decline in atmospheric carbon dioxide concentration during ice ages. Key Points: Reduction of nitrogen fixation in the Atlantic Ocean during ice ages, proportional to sea‐level variations in regional shelf areaRegional coupling between nitrogen fixation and shelf sedimentary denitrification in the subtropical gyresChange in nitrogen fixation cannot explain the lowering of atmospheric CO2 during ice ages [ABSTRACT FROM AUTHOR]

Determining the timing and extent of Quaternary glaciations around the globe is critical to understanding the drivers behind climate change and glacier fluctuations. Evidence from the southern mid-latitudes indicates that local glacial maxima preceded the global Last Glacial Maximum (LGM), implying that feedbacks in the climate system or ice dynamics played a role beyond the underlying orbital forcings. To shed light on these processes, we investigated the glacial landforms shaped and deposited by the Lago Argentino glacier (50° S), an outlet lobe of the former Patagonian Ice Sheet, in southern Argentina. We mapped geomorphological features on the landscape and dated moraine boulders and outwash sediments using 10Be cosmogenic nuclides and feldspar infrared stimulated luminescence (IRSL) to constrain the chronology of glacial advance and retreat. We report that the Lago Argentino glacier lobe reached more extensive limits prior to the global LGM, advancing during the middle to late Pleistocene between 243–132 ka and during Marine Isotope Stage 3 (MIS 3), culminating at 44.5 ± 8.0 and at 36.6 ± 1.0 ka. Our results indicate that the most extensive advance of the last glacial cycle occurred during MIS 3, and we hypothesize that this was a result of longer and colder winters, as well as increased precipitation delivered by a latitudinal migration of the Southern Westerly Winds belt, highlighting the role of local and regional climate feedbacks in modulating ice mass changes in the southern mid-latitudes. [ABSTRACT FROM AUTHOR]

Heterotrophic protists are vital in Earth's ecosystems, influencing carbon and nutrient cycles and occupying key positions in food webs as microbial predators. Fossils and molecular data suggest the emergence of predatory microeukaryotes and the transition to a eukaryote-rich marine environment by 800 million years ago (Ma). Neoproterozoic vase-shaped microfossils (VSMs) linked to Arcellinida testate amoebae represent the oldest evidence of heterotrophic microeukaryotes. This study explores the phylogenetic relationship and divergence times of modern Arcellinida and related taxa using a relaxed molecular clock approach. We estimate the origin of nodes leading to extant members of the Arcellinida Order to have happened during the latest Mesoproterozoic and Neoproterozoic (1054 to 661 Ma), while the divergence of extant infraorders postdates the Silurian. Our results demonstrate that at least one major heterotrophic eukaryote lineage originated during the Neoproterozoic. A putative radiation of eukaryotic groups (e.g., Arcellinida) during the early-Neoproterozoic sustained by favorable ecological and environmental conditions may have contributed to eukaryotic life endurance during the Cryogenian severe ice ages. Moreover, we infer that Arcellinida most likely already inhabited terrestrial habitats during the Neoproterozoic, coexisting with terrestrial Fungi and green algae, before land plant radiation. The most recent extant Arcellinida groups diverged during the Silurian Period, alongside other taxa within Fungi and flowering plants. These findings shed light on heterotrophic microeukaryotes' evolutionary history and ecological significance in Earth's ecosystems, using testate amoebae as a proxy. [ABSTRACT FROM AUTHOR]

Greenland ice core records feature Dansgaard–Oeschger (D‐O) events, which are abrupt warming episodes followed by gradual cooling during ice age climate. The three climate models used in this study (CCSM4, MPI‐ESM, and HadCM3) show spontaneous self‐sustained D‐O‐like oscillations (albeit with differences in amplitude, duration, and shape) in a remarkably similar, narrow window of carbon dioxide (CO2) concentration, roughly 185–230 ppm. This range matches atmospheric CO2 during Marine Isotopic Stage 3 (MIS 3: between 27.8 and 59.4 thousand of years BP, hereafter ka), a period when D‐O events were most frequent. Insights from the three climate models point to North Atlantic (NA) sea‐ice coverage as a key ingredient behind D‐O type oscillations, which acts as a "tipping element." Other climate state properties such as Mean Atlantic Meridional Overturning Circulation strength, global mean temperature and salinity gradient in the Atlantic Ocean do not determine whether D‐O type behavior can occur in all three models. Plain Language Summary: Dansgaard‐Oeschger (D‐O) events are sudden periods of warming followed by slow cooling during ice ages, as observed in Greenland's ice core records. The study used three different climate models to analyze these events, and all models showed similar behavior within a specific range of atmospheric carbon dioxide (CO2) concentrations. This range of CO2 concentrations aligns well with the levels found during the latter half of the last ice age when D‐O events were most frequent. The study found that when CO2 levels are outside this specific range, the climate models settle into one of two stable states, either warm with high CO2 levels or cold with low CO2 levels. These states are stable until CO2 levels reach a certain "tipping point"‐ below around 185–195 ppm for the cold state and above around 217–230 ppm for the warm state. This study suggests that North Atlantic sea ice coverage is a crucial property essential for D‐O like behavior to develop in complex climate models. Key Points: Three complex climate models show internal unforced oscillations at glacial levels of atmospheric carbon dioxide concentrationNorth Atlantic (NA) sea‐ice coverage plays a crucial role behind Dansgaard–Oeschger type behavior in all three modelsThe three models reproduce oscillations in a similar range of NA sea ice coverage [ABSTRACT FROM AUTHOR]

Climate contrasts across drainage divides, such as orographic precipitation, are ubiquitous in mountain ranges, and as a result, mountain topography is often asymmetric. During glacial periods, these climate gradients can generate asymmetric glaciation, which may modify topographic asymmetry and drive divide migration during glacial‐interglacial cycles. Here we quantify topographic asymmetry caused by asymmetric glaciation and its sensitivity to different climate scenarios. Using an analytical model of a steady‐state glacial profile, we find that the degree of topographic asymmetry is primarily controlled by differences in the equilibrium line altitude across the divide. Our results show that glacial erosion can respond to the same climate asymmetry differently than fluvial erosion. When there are precipitation differences across the divide, glacial erosion produces greater topographic asymmetry than fluvial erosion, all else equal. These findings suggest that glaciations may promote drainage reorganization and landscape transience in intermittently glaciated mountain ranges. Plain Language Summary: In mountainous regions, the amount of rain, snow, and ice that falls and builds up often varies from one side of a mountain to the other. Over thousands to millions of years, these variations can make the length and steepness of the mountain sides differ, too. When glaciers form during ice ages, they can make this asymmetry in the topography even more pronounced. Our study looks at how glaciers affect the landscape and how glaciers and landscapes change in different climate conditions. Using a computer model, we discovered that the landscape becomes even more asymmetric when it is shaped by glaciers compared to when it is shaped by rivers. Our findings suggest that glaciers can cause landscapes to constantly change between ice ages. Key Points: We quantify topographic asymmetry caused by asymmetric glaciationGlacial erosion causes greater topographic asymmetry than fluvial erosion all else equalGlacial‐interglacial cycles can cause divide migration [ABSTRACT FROM AUTHOR]

Scientists and policy‐makers promote 'Nature‐based Solutions' to the interconnected challenges associated with the Anthropocene. Often these involve the strategic use of ecosystem engineers: animals, plants, and microbes with disproportionate ecological agency capable of regional or even planetary‐scale niche construction. This environmental mode of biopolitics is promoted as biomimicry: restoring, rewilding, or rewetting diverse ecological systems. This paper critically examines the multispecies relations promised by this model through a focus on beaver in Britain over the last 12,000 years. It begins with beaver making Britain hospitable for early settlers and agriculturalists as they returned after the last ice age. It traces the subsequent demise of beaver due to hunting and land use change, and then follows the recent return of beaver as tools for natural flood management and nature recovery. It attends to situations in which these multispecies world‐making projects go awry in the weird ecologies of the Anthropocene. This story of beaver helps situate enthusiasms for proactive ecosystem engineering in deeper time. It highlights the beguiling potential of Nature‐based Solutions while cautioning against tendencies towards anthropocentrism, an apolitical mononaturalism, and an ecomodernist hubris. The paper combines concepts from archaeology, ecology, anthropology, and geography into a new framework for theorising multispecies acts of worlding and weirding. [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]

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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]

The last glacial inception (LGI) marks the transition from the interglacial warm climate to the glacial period with extensive Northern Hemisphere ice sheets and colder climate. This transition is initiated by decreasing boreal summer insolation but requires positive feedbacks to stimulate the appearance of perennial snow. We perform simulations of LGI with climate model AWI‐ESM‐2.1, forced by the astronomical and greenhouse gas forcing of 115,000 years before present. To compare with the preindustrial (PI) simulation, we use a consistent definition of the seasons during the LGI and the PI and evaluate model output on an angular astronomical calendar. Our study reveals a prominent role of the sea‐ice albedo feedback to amplify the delayed climate signal at polar latitudes. Through a radiative budget analysis, we examine that the ice‐albedo feedback exceeds the shortwave radiative forcing, contributing to the cooling and high latitude snow built‐up during LGI. Plain Language Summary: The onset of the last ice age marks the transition from the interglacial warm climate to the ice age with extensive Northern Hemisphere (NH) ice sheets and colder climate. This transition is initiated by decreasing boreal summer irradiance and reinforced by positive feedbacks. We perform climate simulations under the astronomical and greenhouse gas forcing, and use a consistent definition of seasons. Our study shows that a delayed ice‐albedo feedback plays an important role in generating a cold NH climate. Key Points: Climate simulations reveal year‐round cooling in the Northern Hemisphere high latitudes during the last glacial inceptionA refined angular calendar provides a tool to analyze the seasonal dynamicsWe identify the crucial role of the albedo feedback on the high‐latitude radiative budget [ABSTRACT FROM AUTHOR]

Over the last four decades, organic-walled dinoflagellate cysts have shown high potential as tracers of past sea-surface conditions during the Quaternary. These microfossils relate to the pelagic productivity of both phototrophic and heterotrophic protist organisms and are recovered in high numbers in almost all marine environment settings from the nearshore and estuarine systems to the distal continental margin. In polar environments, where other conventional proxies are rare or absent, dinoflagellate cysts showed a relatively high diversity of species and a close relationship with sea-ice cover duration, winter and summer temperature, and salinity, enabling quantitative reconstructions of several oceanic variables over time. From the temperate to the tropical latitudes of the Atlantic Ocean, their modern distribution highlights a response to primary productivity and seasonal contrasts in surface temperature. They also have proven that they could be used as tracers of eutrophication in stratified systems and can also highlight human impact on their distribution. In this paper, we present an overview of dinoflagellate cysts as ecological tracers in recent and past sediments of the Atlantic Ocean, from the Arctic to the Antarctic. We provide examples of their use as proxies in paleoclimatic-palaeoceanographic studies at glacial to interglacial time scales, with emphasis on the last ice age to recent (last 25 kyr), the northern North Atlantic and western-eastern tropic North Atlantic. We also discuss their potential as tracers of anthropogenic stress in coastal environments. [ABSTRACT FROM AUTHOR]

The extinction of the woolly rhinoceros (Coelodonta antiquitatis) at the onset of the Holocene remains an enigma, with conflicting evidence regarding its cause and spatiotemporal dynamics. This partly reflects challenges in determining demographic responses of late Quaternary megafauna to climatic and anthropogenic causal drivers with available genetic and paleontological techniques. Here, we show that elucidating mechanisms of ancient extinctions can benefit from a detailed understanding of fine-scale metapopulation dynamics, operating over many millennia. Using an abundant fossil record, ancient DNA, and high-resolution simulation models, we untangle the ecological mechanisms and causal drivers that are likely to have been integral in the decline and later extinction of the woolly rhinoceros. Our 52,000-y reconstruction of distribution-wide metapopulation dynamics supports a pathway to extinction that began long before the Holocene, when the combination of cooling temperatures and low but sustained hunting by humans trapped woolly rhinoceroses in suboptimal habitats along the southern edge of their range. Modeling indicates that this ecological trap intensified after the end of the last ice age, preventing colonization of newly formed suitable habitats, weakening stabilizing metapopulation processes, triggering the extinction of the woolly rhinoceros in the early Holocene. Our findings suggest that fragmentation and resultant metapopulation dynamics should be explicitly considered in explanations of late Quaternary megafauna extinctions, sending a clarion call to the fragility of the remaining large-bodied grazers restricted to disjunct fragments of poor-quality habitat due to anthropogenic environmental change. [ABSTRACT FROM AUTHOR]

Little has been published on post-glacial migration corridors of fishes in New England during the Wisconsinan Glaciation. I present an updated review of current literature on the origin of fish species in Vermont, with the focus on the Connecticut River and Champlain–Richelieu–St. Lawrence River drainage networks. A more accurate picture of post-glacial migration routes can provide a basis for determining whether a species is native to Vermont. Vermont supports fishes from 2 main refugial groups: the species-rich western and the relatively species-poor eastern refugia. Eastern species are native throughout the state, while western species are native only to lower elevations of the the Champlain drainage. Vermont's 80 native species far exceeds any other New England state due to the addition of 40 western species. Twenty-three species may have dispersed from both major refugial regions, 12 species dispersed only from the eastern refugia, 4 species are anadromous, and 1 is catadromous. Recently revised aging of ice retreat and subsequent waterbody formation linked to putative recolonization routes can clarify native status, particularly in Vermont, where many western refugial species share their eastern-most limits of their natural distributions. I propose probable origin status to native Vermont species with respect to major Vermont drainages. [ABSTRACT FROM AUTHOR]

Objective: Lacking a thorough comprehension of the psychological phenomenon, professionals engage in psychotherapy. Throughout history, humanity has been exploring the essential question: What are the origins, roots, and essence of the psychological phenomenon? The primary goal of this study is to elucidate these enigmas. Despite notable progress in the realm of psychology, the psychological phenomenon remains a paramount unanswered query, still enigmatic. Methods: The research methodology utilized Grounded Theory for fundamental concept formation and content analysis. Within the "understanding-based content analysis" approach, 32 analytical units within the content units (texts and well-documented sources in the theoretical foundations of the research) linked to the psychological phenomenon were scrutinized across 14 eras (Era1 to Era14). Results: The results indicate that psychology emerges as an unparalleled consequence of the creative progression of life in organisms, particularly evolving from two nested evolutionary shifts. Initially in all primates, a type of consciousness, specifically heightened momentary awareness, developed as a means of communication. This mechanism, involving the prefrontal cortex and long-range circuits, facilitates the transmission of neural information throughout the brain in ascending and descending (feedback) patterns. Subsequently, this communicative capacity was exclusive to the reflective Homo sapiens, along with a secondary genetic alteration around the conclusion of the previous Ice Age (between 40,000 to 100,000 years ago). This was notably enabled by a mutation in the FOXP2 gene, fostering functional coordination among the lungs, larynx, throat, tongue, and other components. Conclusions: The outcomes aid in broadening the understanding of the nature of the psychological phenomenon. [ABSTRACT FROM AUTHOR]

Dust is a mineral aerosol of the atmosphere that often contains trace elements such as As, Cd, and Pb. Lhù'ààn Mân' (Kluane Lake), located in southwestern Yukon, is a region of frequent dust activity. In 2016, the lake level fell due to a dramatic decrease in inflow from glacier meltwater, and the delta of the lake became an important source of dust to surrounding ecosystems. To determine the impacts of dust deposition on vegetation and soil trace element concentrations and characteristics, we sampled the lichen Peltigera canina and soil layers at 57 sites along a deposition gradient located 1.4–33.6 km downwind from the principal dust source. Arsenic, Cd, Cu, Ni and Pb in lichens were negatively correlated with the distance away from the dust source, with the highest correlations in Ni and Pb (r2 = 0.50 and 0.48, respectively). Lichen and tree abundances were negatively impacted by dust deposition, suggesting that dust can affect ecosystem vegetation composition. Starting 8 km away from the dust source, the concentrations of As, Ni, and Pb decreased by more than 50% per km, while Cd and Cu concentrations decreased by more than 40% per km. Overall, within the sampled ecosystems, soil pH is 1.4 times higher in the first 8 km from the dust source while carbon content and nutrients are lower, which implies changes in nutrient availability and cycling in dust‐affected ecosystems. Plain Language Summary: The delta of Lhù'ààn Mân' (Kluane Lake), located in southwest Yukon and on the traditional lands of Kluane First Nation, Champagne‐Aishihik First Nation, and White River First Nation, is an area where dust often settles and climate change has accelerated the melting of glaciers since the last ice age. Due to reduced glacier water flowing into the lake, the sediments in the delta are more exposed to wind, creating dust storms. To understand the impacts of dust deposition within the surrounding ecosystems, we assessed the levels of trace metals in lichens and soils across a gradient from the delta to the lake. We found that distance from the dust source affected trace metal concentrations in lichens, surface soils, and vegetation. It is essential to understand how these metals spread as they can be potentially toxic and harmful to ecosystems and humans. Key Points: Dust deposition, indicated by high trace element concentrations, is higher closest to the delta of the Ä'ą̈y Chù' into Lhù'ààn Mân'Evidence for dust deposition at Lhù'ààn Mân' can be found in trace elements of the 0–2 cm soil layer and lichens influenced by distanceVegetation characteristics are impacted by dust deposition more than soil characteristics [ABSTRACT FROM AUTHOR]

Large paleochannels with sizes far greater than the modern ones are widespread on the floodplains and low terraces of rivers in the Volga basin. These are indicators of higher values of river runoff in the end of the latest glacial epoch. The assessment of the time interval of the epoch of abundant runoff requires the determination of the age of large paleochannels. With this in view, drilling of large paleochannels has been carried out all over the Volga basin. Radiocarbon dating of the channel alluvium was carried out. The majority of dates lied within the time interval 14.5–17.0 thousand years ago, which suggests the conclusion that the epoch of abundant river flow approximately coincides in time with the early Khvalynian transgression of the Caspian Sea. [ABSTRACT FROM AUTHOR]

"Capturing Glaciers: A History of Repeat Photography and Global Warming" by Dani Inkpen explores the significance of repeat scientific photographs of glaciers taken years apart to demonstrate global warming. The book delves into the questions of how such images function as evidence, their changing purposes and audiences, and the impact of factors like nationalism and military competition on their value. Inkpen's work engages with history, sociology of science, and representational theory to provide a comprehensive analysis of glacier photography and its evolving role in society. [Extracted from the article]