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Social mobilizations for sustainability transformations

Overlooked and overexploited: Extensive conversion of grasslands and wetlands driven by global food, feed, and bioenergy demand

Natural ecosystems are increasingly threatened by global agricultural supply chains, and a narrow policy focus on forests has fueled agricultural expansion into ecologically significant but severely overlooked non-forest ecosystems, including grasslands and open wetlands. While a few emerging policies attempt to protect non-forest ecosystems, a globally consistent assessment of their conversion extent and drivers, especially related to livestock production and commodity-specific supply chain demand, remains lacking. Here, we conducted a spatially explicit analysis to identify pasture and cropland expansion into non-forest ecosystems between 2005 and 2020, as well as conversion-linked primary agricultural commodities and their underlying demand drivers (end uses and final market destinations). We found that the conversion rate of natural non-forest ecosystems was nearly four times that of lands with tree cover exceeding 5 m (a common forest height threshold), with Brazil contributing 13% of the global total and Russia, India, China, and the United States each contributing about 6%. While drivers varied greatly across regions, globally 50% of the conversion was linked to pasture, and 27, 17, and 6% to cropland for food, feed, and other uses (mainly bioenergy), respectively. Among conversion-linked commodities, most livestock-associated products served domestic demand, while 32% of feed crops and 20% of all crops were exported, with export shares reaching 70 to 80% in Brazil and Argentina. These findings reveal important areas for non-forest ecosystem conservation and highlight the need for integrated policies to prevent leakage across different ecosystems and different sustainable development goals while also aligning local actions with global supply chain governance.

Navigating the mysterious space of evolutionary histories

The way of life: The network challenge of blood flow in the brain

Studying adaptation at the invisible scale

In order to understand adaptation by natural selection, it is necessary to observe organisms in their natural habitat. For this reason, the field of behavioral ecology, which specializes in testing adaptive explanations for biological observations, is dominated by research on larger multicellular animals such as insects, mammals, fish, and birds. The vast majority of modern life sciences, however, is concerned with the study of cells, genes, and molecules, which are often impossible to observe directly in nature. This severely compromises our ability to complement mechanistic understand of traits of interest with adaptive understanding. This matters because only the theory of adaptation can provide an explanation for why biology operates in the way that it does, why it varies across individuals and species, a formal tool for making predictions about the future. The good news is that technological advances are creating new opportunities for understanding cellular and subcellular traits as the products of natural selection.

Phenotypic polymorphism via mate copying

Classical mate choice theories assume independent decision-making, yet mounting evidence shows that individuals often use social information and copy conspecifics’ mate choices, a behavior termed mate copying. While this nonindependent mate choice has been documented across vertebrates and notably in Drosophila melanogaster , theoretical and experimental frameworks have been mainly restricted to binary choice scenarios, limiting our understanding of its evolutionary implications in natural populations. Here, we develop a theoretical model of mate copying applicable to populations with multiple morphs, incorporating both private (inherent) and public (cultural) information in mate choice decisions. The population dynamics of the different male morphs are driven by the differing intensities of conformist and anticonformist mate copying. We demonstrate that mate copying can lead to the fixation of low-quality morphs and identify the conditions necessary for the existence of a polymorphism consisting of all male morphs in the population. Furthermore, we identify a plausible mechanism that could maintain a stable polymorphism in the case of conformist mate copying with two morphs. Our findings provide a theoretical framework for understanding how social learning in mate choice can influence evolutionary trajectories and contribute to maintaining phenotypic diversity in populations, with potential implications for sexual selection and speciation.

Structural and evolutionary constraints of organophosphate resistance in dipteran carboxylesterases

Enzymatic detoxification of organophosphate (OP) insecticides can confer resistance in some insects, yet the precise molecular basis of this trait, and how it has evolved, remains poorly understood. In certain dipteran species, a G→D mutation in the oxyanion hole of α-carboxylesterases (CBEs) enhances OP hydrolysis, yet this adaptation is not widespread despite the presence of orthologous CBEs in other insect species that are also exposed to OPs. The extent, and molecular basis, of evolutionary contingency and epistasis in this catalytic OP resistance has not been explored, and how further mutations might optimize OP detoxification in the future is not clear. Here, we systematically compare OP hydrolysis and analyze structures of CBE orthologs across several dipteran species, revealing that the success of the G137D mutation is sequence context-dependent. We employed laboratory-directed evolution to enhance OP turnover over 1,000-fold vs. the wildtype enzyme and tested these variants in transgenic Drosophila melanogaster , demonstrating that improved catalytic rates do not directly translate to increased resistance. By highlighting the trade-off between organophosphate affinity and turnover, this work further clarifies the complex evolutionary trajectories determining why a particular resistance mechanism may evolve in some species but not others.

The cognitive underpinnings of minority overestimation

Kava consumption and the rise of sociopolitical complexity in Oceania

Humans have been using psychoactive substances for millennia, despite their potential negative health and social consequences. According to some scholars, our craving for mind-altering drugs is an evolutionary mistake—a hijacking of our reward system. In contrast, the “drunk hypothesis” argues that intoxication has been adaptive and essential for the rise of large-scale societies because it promotes social bonding, increases cooperation, alleviates stress, and enhances human creativity. Here, we test this hypothesis using the example of kava, a traditional Pacific beverage with a range of psychoactive effects, made from the root of Piper methysticum . Our analysis of 83 Oceanic-speaking societies shows a positive relationship between traditional kava consumption and both political complexity and social stratification. However, the results are not robust to controls for nonindependence. Moreover, we found no evidence of coevolution between kava drinking and either of the two sociopolitical traits after controlling for spatial nonindependence. Despite the cultural significance of kava in many Pacific societies, our results suggest that its consumption was unlikely to have been a major driver of sociopolitical complexity, underscoring the importance of controlling for nonindependence in cross-cultural studies.

Tectonism rather than “snowball Earth” glaciation is responsible for the Great Unconformity

The Great Unconformity (GUn)—a widely recognized discontinuity and associated gap in the rock record between Precambrian and Cambrian rocks—represents a globally important interval of continental exposure and erosion that is notable also for the first appearance of all major animal phyla on Earth. However, its origin remains the subject of vigorous debate. Here, we present field relationships, and zircon and monazite U–Pb, biotite and muscovite Rb–Sr, and zircon (U–Th)/He thermochronology data for Precambrian crystalline basement rocks from North China to constrain the exhumation history below the unconformity. Dates from multichronometers and thermal history inversions show that the most substantial cooling of continental basement took place from ~2,100 to 1,600 Ma. Comparison with thermal history data from Laurentia, Baltica, and Amazonia suggests that protracted plate tectonics broadly modulated by supercontinent cycles, and not “snowball Earth” glaciation, is responsible for crustal exhumation below the unconformity. The most pronounced erosion evident in both the thermochronologic record and geochemical indicators of continental weathering is shown to correspond with development of Earth’s first true supercontinent (Columbia), rather than with either the Cambrian explosion or the emergence of modern plate tectonics.

Accelerated north–east shift of the global green wave trajectory

Viewed from space, a “green wave” seasonally traverses Earth’s surface, from the north in boreal summer to the south in austral summer. This wave represents vegetation phenology, driven primarily by solar irradiation and modulated by climate variability and ecosystem dynamics. Despite its significance for multiple Earth system processes, we lack a unified metric to characterize and understand its dynamics. Here, we propose a concept to quantify global phenology by tracking the green wave’s centroid using satellite and Earth system model data. The resulting trajectory summarizes global phenological dynamics and directional trends. Earlier reports on global greening led us to hypothesize a rapidly northward shifting trajectory during boreal summer and a moderate southward shift during austral summer. Contrary to this expectation, we find that the centroid moves northward during both summer periods, with the austral summer shift consistently exceeding the boreal shift across datasets. As a consequence, the amplitude of the green wave trajectory is decreasing, a trend projected to intensify throughout this century. We also detect an accelerating eastward shift, a phenomenon not previously reported. Tracking the green wave’s centroid reveals how regionally changing land dynamics affect the global functioning of Earth’s terrestrial biosphere.

Effects of correlated collisions and intermittency on the growth of lucky droplets

To trigger precipitation, water droplets in warm clouds need to attain a sufficient size. Theoretical estimates based on condensation and gravitational collisions alone fail to explain the observed timescales for the onset of precipitation for a range of droplet sizes. This suggests the involvement of collisional growth mediated by turbulence to resolve the so-called “size-gap problem.” For the onset of rain, it is sufficient that statistical outliers, coined “lucky droplets,” cross the size gap. In this study, we explore the influence of turbulence on droplet growth, focusing on correlated collisions and intermittency. Using direct numerical simulations of droplets in turbulent flow, we constrain a non-Markovian stochastic framework that allows us to assess memory effects on the droplet-size distribution arising from correlations between consecutive collisions. Using our framework, we find that correlated collisions accelerate the initial growth of lucky droplets but have subleading effect at later stages. Consequently, we neglect correlations from collisions and model an ensemble of cloud parcels representing fluctuations in the volume-averaged dissipation rate. Here, the distribution of droplet sizes in each parcel is described by a linear master equation with a time-dependent collision rate according to the volume-averaged dissipation rate. Our analyses of this toy model show that intermittency can significantly reduce the time required by lucky droplets to cross the size gap.

Chemodivergent Coupling of 1,3-Enynes with Anilines to Access Dihydropyrrole Skeleton under Palladium Catalysis

Impacts of air pollution on farmers’ subjective satisfaction in China’s ore and agricultural zone

Pressure dependence of surface tension of polymer melts under high vacuum

Aging-related severe hypertension causes prostatic gland atrophy and testicular injury in rats

Abstract The combined effects of aging and hypertension on the male reproduction system remain unclear. We investigated these effects on prostate and testis from histological and endocrinological perspectives. Male spontaneously hypertensive rats (SHRs) and normotensive Wistar Kyoto rats (WKYs) (n = 8 per group) were evaluated at 36 weeks (adult) and 72 weeks (aged). Compared with age-matched WKYs, adult SHRs showed significantly higher prostate weight, prostate weight-to-body weight ratio and glandular epithelial area in the ventral prostate. On the contrary, aged SHRs showed significantly lower prostate weight and outer glandular perimeter than age-matched WKYs. At both ages, SHRs had significantly higher blood pressure and lower prostatic blood flow than age-matched WKYs, and aging-dependent increase in the blood pressure was observed in SHRs but not in WKYs. Aged SHRs had significantly lower serum testosterone levels, higher testicular weight-to-body weight ratios, seminiferous epithelial desquamation and neutrophil infiltration than aged WKYs, while these alterations were not obvious in adult SHRs. In conclusion, whereas adult SHRs exhibit prostatic hyperplasia, aged SHRs exhibit severe hypertension, prostatic atrophy, testicular injury, and reduced serum testosterone levels. Aging-related severe hypertension may be a risk factor for prostatic atrophy which might be related to reduced testosterone levels.

Contrary effects of soil moisture-atmosphere feedback on dry and humid heatwaves

Ginsenoside Rg1 ameliorates lipopolysaccharide-induced depressive-like behaviors in mice by attenuating neuroinflammation and neuronal damage

Mitotic microhomology-mediated break-induced replication promotes chromoanasynthesis

Abstract Chromoanasynthesis is a form of complex chromosomal rearrangement (CCR) commonly detected in cancers and congenital disorders, but the mechanism underlying its generation remain elusive. Here we develop a single-molecule long-read DNA sequencing approach to characterise ultra-complex mutational events, consistent with chromoanasynthesis, occurring at shortened telomeres and sub-telomeric DNA double-strand breaks in human cells. Our data reveal that chromoanasynthesis is generated by microhomology-mediated break-induced replication (MM-BIR), occurring specifically in mitosis. Surprisingly, this mitotic pathway involves a collaboration between microhomology-mediated end-joining (MMEJ) and BIR, where MMEJ proteins initiate a Polδ-dependent BIR pathway that is regulated by PIF1, POLD3 and PCNA. This pathway is highly prone to template switching and can generate dramatic amplification of genomic loci in a single event. Our findings help explain the extreme mutagenic nature of chromoanasynthesis and establish mitotic MM-BIR as a key driver of CCRs, with important implications for the origin of cancers and congenital disorders.

A physics-guided machine learning framework for enhancing dust storm visibility prediction in arid and semi-arid regions