Polymorphism, the occurrence of different morphs of a trait within the population of a single species, plays a crucial role in species diversification, genetic variation, and adaptation. Detecting polymorphism in a single character helps us to understand population dynamics, particularly in species that inhabit diverse environments. However, detecting polymorphisms in fossil taxa is challenging due to the fragmentary and incomplete records. Dimorphism, defined as the occurrence of different morphs of a trait within the population of a single species, represents the simplest and most common form of polymorphism. This study focuses on dimorphism instead of polymorphism, which allows for a more streamlined analysis. We use computational simulation experiments to estimate the minimum sample size required to detect bimodal distribution in univariate morphological variables. We describe the morphological diversity of a measured variable (e.g., body mass or skeletal length) as a probability density distribution with specific parameter sets. Subsequently, we simulate the diversity of the measured variable with varying sample sizes and conduct resampling procedures to ensure the robustness. Four key parameters that characterize the probability distribution are identified as having significant influence on the minimum sample size for dimorphism recognition. According to the simulation experiments, a model is built to estimate the minimum sample size for dimorphism recognition based on these parameters. A dataset from extant avian and reptilian species is used to test the model. Furthermore, we calculate a reference for the minimal sample size required for assessing phenotypic dimorphism in fossil avian taxa by applying parameters derived from extant avian species.

Carbon capture technologies are considered essential for addressing global warming issues. To date, various capture technologies have been extensively investigated in the literature, both through experimental studies and simulations. This paper aims to briefly review the most recent advancements in the modeling of various CO2 capture processes. The progress in technologies, including chemical absorption, physical absorption, adsorption, membrane-based separation and chemical looping processes, is discussed. Existing evaluation results obtained from various simulation studies are summarized and compared. In addition to the advancements in each technology, the future research trends and the challenges that need to be addressed in the field of process modeling are identified.

Glacier motion, retreat and glacier hazards such as surges and glacial lake outburst floods (GLOFs) are likely underpinned by subglacial hydrology. Recent advances in subglacial hydrological modeling allow us to shed light on subglacial processes that lead to changes in ice mass balance in High Mountain Asia. We present the first application of the Subglacial Hydrology And Kinetic, Transient Interactions (SHAKTI) model on an alpine glacier. Shishper Glacier, our study site, is a mountain glacier in northern Pakistan that exhibits concurrent surges and GLOFs, which endanger local communities and infrastructure. Without coupling to ice velocity, the modeled subglacial hydrological system undergoes transitions between inefficient to efficient drainage and back during spring and fall, supporting previous observations of spring and fall speedups of glaciers in the region. We compare modeled effective pressures from the years 2017-19 with previously observed velocities, suggesting that while subglacial hydrology may explain seasonal sliding dynamics, our model is unable to provide an explanation for surge-scale behavior, implicating a need for coupled hydrological and ice dynamics modeling of surge conditions. This work demonstrates the potential of using ice sheet models for alpine glaciology and provides a new nucleus for modeling of glacial hazards in alpine environments.

As apex predators, giant otters (Pteronura brasiliensis) are susceptible to the bioaccumulation of heavy metals, particularly in regions where gold-mining contributes to mercury (Hg) pollution. This is the broadest-scale study assessing Hg and selenium (Se) concentrations in the Pantanal. Samples from 10 sites across the Pantanal were analysed using inductively coupled plasma mass spectrometry. We constructed a two-factor generalized additive model (GAM) to investigate the relationship between Hg concentrations in giant otters and their location along river courses in gold-mining areas. To determine the feasibility of merging the dataset from the present study with the dataset of a previous study carried out by our group during 2016–2017, we included the datasets as a factor in the analysis. The GAM results supported the feasibility of merging the datasets. Additionally, we measured Se concentrations due to their potential to mitigate Hg toxicity. Higher Hg levels were found in otters from watercourses near gold-mining areas, with concentrations decreasing downstream, revealing a contamination gradient and the extensive impact of local pollution on wetlands. The highest Hg concentration was recorded in the Bento Gomes River, within a gold-mining area, whereas otters from unconnected sites exhibited lower Hg levels.

In 1893, the British explorer Frederick George Jackson travelled in the north of the Russian Empire, where he learned lessons—particularly in the areas of diet, transport, and clothing—from the Nenets and Sami people. I argue that his travels in this area influenced both his subsequent Jackson-Harmsworth Expedition (1894–97) and British Antarctic expeditions in the early 20th century, including those led by Robert F. Scott and Ernest H. Shackleton

Studying Jackson’s travels and writings can advance discussions about the role of Indigenous knowledge in British Polar exploration in the late 19th and early 20th centuries.

Based on a new reading of both published and archival materials, the paper also charts some forms of knowledge that Jackson struggled to appropriate—particularly the use of reindeer for transport. In examining his failures, I argue that attempts to write Indigenous contributions into the history of exploration must focus on explorers’ failures as well as their successes—and on forms of Indigenous knowledge that proved difficult to use in other contexts.

Accelerated glacier mass loss across the Antarctic Peninsula has consequences for sea level rise and local ecology. However, there are few direct glaciological observations available from this region. Here, we reveal glacier changes on the James Ross Archipelago between 2010 and 2023. The median rate of glacier area loss (remote-sensing derived) increased over the study period, with the most significant changes observed in smaller glaciers. In situ measurements show that ablation has prevailed since 2019/20 with the most negative point surface mass balance change measured as −1.39 ± 0.12 m water equivalent at Davies Dome and Lookalike Glacier in 2022/23 (200–300 m a.s.l.). We identified a tripling of the frontal velocity of Kotick Glacier in 2015, which, combined with terminus surface elevation gains (bulging), suggests that this is the first surge-type glacier identified in Antarctica from velocity and surface elevation change observations. We contend that the glacier recession rate has increased due to increased air temperatures (0.24 ± 0.08°C yr−1, 2010–23), decreased albedo and glacier elevation change feedbacks. These processes could decrease glacier longevity on the archipelago. Future research should prioritise monitoring albedo and rising equilibrium-line altitudes and identify glaciers most vulnerable to rapid future mass loss.

The Caribbean islands represent some of the most biologically diverse places on Earth, but much of that diversity is now at risk due to human impact. Larger islands in the Caribbean host more native species, but small islands still hold together a significant portion of the regional biota. Although our knowledge of extinct and extirpated taxa continues to improve, there are hundreds of islands, each with their own unique faunal histories from where there is little information about their ancient diversity. Sombrero is a very small island (0.38 km2) located within the limits between the Greater and Lesser Antilles and is largely barren of vegetation and freshwater. The island was extensively mined for bird guano in the 1800s, which profoundly altered its topography and fauna. Here, we describe a collection of microvertebrates recovered in 1964 from Sombrero, which documents an unexpectedly high number of colonization events and high extinction rate for this territory. The late Quaternary deposits from the island contain remains of five types of lizards, a snake, a tortoise, and an anuran that colonized the island once it became aerially exposed in the early Pleistocene. The ability for such a small, remote island to have eight colonizing taxa in < 2.5 Ma, provides support for the role that island hopping played in regional biodiversity in the Cenozoic (e.g., GAARlandia), even across small, barren islands. Furthermore, these fossils further show that large scale defaunation also affected vertebrate communities on very small islands in the Caribbean.

Landscape evolution in karst terrains affects both subterranean and surface settings. For better understanding of controlling processes and connections between the two, multiple geochronometers were used to date sediments and speleothems in upper-level passages of Fitton Cave adjacent to the Buffalo River, northern Arkansas, within the southern Ozark Plateau. Burial cosmogenic-nuclide dating of coarse sediments indicates that gravel pulses washed into upper passages at 2.2 Ma and 1.25 Ma. These represent the oldest epigenetic cave deposits documented in this region. Associated sands and clay-rich sediments mostly have reversed magnetic polarity and thermally transferred optically stimulated luminescence dates of 1.2 to 1.0 Ma. Abandonment of these upper passages began before 0.72 Ma, when coarse sediment was deposited in a passage incised below older sediment. Maximum U-series dates of 0.7–0.4 Ma for flowstones capping clastic deposits mark the stabilization of older sediments and a change to vadose conditions that allowed post–0.4 Ma stalagmite growth. Resulting valley incision rates since 0.85 Ma are estimated at 27 m/Ma. Coarse cave-sediment pulses correlate to Laurentide glacial tills about 300 km to the north, suggesting climate influence on periglacial sediment production. Dated cave sediments also may correlate with undated older strath terraces preserved at similar heights above the Buffalo River.

Sít’ Tlein (Malaspina Glacier), located in Southeast Alaska, has a complex flow history. This piedmont glacier, the largest in the world, is fed by three main tributaries that all exhibit similar flow patterns, yet with varying surge cycles. The piedmont lobe is dramatically reshaped by surges that occur at approximately decadal timescales. By combining historical accounts with modern remote sensing data, we derive a surge history over the past century. We leverage the Stochastic Matrix Factorization, a novel data analysis and interpolation technique, to process and interpret large datasets of glacier surface velocities. A variant of the Principal Component Analysis allows us to uncover spatial and temporal patterns in ice dynamics. We show that Sít’ Tlein displays a wide range of behaviors, spanning quiescence to surge with seasonal to decadal variations of ice flow direction and magnitude. We find that in the lobe, surges dominate the velocity dataset’s variance (spanning 1984–2021), while seasonal variations represent a much smaller part of the variance. However, despite the regular surge pulses, the glacier lobe is far from equilibrium, and widespread retreat of the glacier is inevitable, even without further climate warming.

Due to the nascency of synthetically derived biological systems, there is a need to develop protocols for safety and security management. These protocols can be adapted from existing safety and security protocols (e.g., Biosafety Level Classification of biological agents) as well as NASA’s and ESA’s planetary protection guidelines. Currently, NASA is preparing for its first sample return mission from Mars including determining how to manage the types of hazards that may be returned to Earth. Synthetic biology can look to risk management practices from related disciplines, and NASA can look to its established protocols from lunar exploration as it strives to minimize Mars sample return bio-risk. Notably, the biosafety concerns of synthetic cell research are very similar to those of planetary back-contamination from extraterrestrial samples. Thus, the measures taken to limit planetary back-contamination can serve to help develop biosafety protocols for synthetic cell research. We summarize existing tools used in planetary protection that can be repurposed to establish protocols for synthetic cell safety and security.

Cosmogenic 7Be and 10Be are effective tracers for studying atmospheric dynamics and Earth’s surface processes, with over 90% of these isotopes reaching the surface via wet deposition. However, the characteristics and influencing factors of 7Be and 10Be wet deposition remain unclear in different regions, limiting the precision of these nuclides as tracers of environmental change. This study analyzes the annual variation of 7Be and 10Be wet deposition in Xi’an and examines the impact of precipitation on their deposition. Ultra-trace levels of 7Be and 10Be in precipitation were synchronously measured using state-of-the-art accelerator mass spectrometry. One-year (July 30, 2020 to September 3, 2021), high-frequency (individual rain events) and time-synchronized series of observations of 7Be and 10Be wet deposition data (n = 49) were analyzed. The total annual wet deposition fluxes of 7Be and 10Be in central China (34.22°N, 109.01°E) for 2020/21 were (218 ± 24) × 108 atoms·m–2·yr–1 and (314 ± 16) × 108 atoms·m–2·yr–1, respectively. Precipitation amount, intensity, and duration were quantitatively analyzed for their effects on total wet deposition flux, mean concentration, washout ratio, deposition velocity, and scavenging coefficient of 7Be and 10Be during individual rain events. The results indicate that precipitation amount is the most significant factor influencing the wet deposition flux of both nuclides.