Life Forms Research Articles

ToTE: A global database on trees of the treeline ecotone.

Globally, treelines form a transition zone between tree-dominated forest downslope and treeless alpine vegetation upslope. Treelines represent the highest boundary of "tree" life form in high-elevation mountains and at high latitudes. Recently, treelines have been shifting upslope in response to climate warming, so it has become important to understand global tree diversity and treeline distributions. However, to the best of our knowledge, no global database on tree flora of treelines exists, which limits our capacity to undertake macroecological analyses. Here, for the first time, we present a global data set on the trees of the treeline ecotone, supported by an online ToTE database. We synthesized the database from 1202 studies published over the last 60 years (1962 to 2022) following the Preferred Reporting Items in Systematic Reviews and Meta-Analysis (PRISMA) protocol. We classified the tree species in the database into three categories: treeline tree (TL) species, near to treeline (NTL) tree species, and tree species with an upper montane range limit (TUMR). The ToTE Version-1 presents a total of 208 tree taxa, including 189 species, five subspecies, and 14 varieties, belonging to 54 genera and 26 families distributed across 34 mountain regions worldwide that either grow exactly at the treeline or have a range limit below the treeline. Of the total taxa, 155, 14, and 39 belong to TL, NTL, and TUMR, respectively. Genera such as Abies, Picea, Pinus, Larix, and Juniperus are more represented in the treeline tree category. On the other hand, Acer, Prunus, Populus, and Quercus have more representatives in the near to treeline category, whereas Erica, Nothofagus, and Polylepis contribute more tree species with an upper montane range limit. Furthermore, families such as Rosaceae and Pinaceae include trees that occur both at the treeline and with an upper montane range limit, whereas Sapindaceae includes trees that occur exclusively near to treeline. Our database also includes information on the global distribution patterns of treeline tree species richness across mountains and biomes. The mountains with the highest number of tree species are the Andes (39) followed by the Himalaya (37). Close to 67% of tree species show restricted distributions in different mountains, with the highest endemism in the Andes and the Himalaya. In terms of tree species distribution, Pinus sylvestris was widespread, with a distribution across nine mountain regions, followed by Picea glauca and Fagus sylvatica, both distributed across five mountain regions. In terms of species' distribution across biomes, the temperate biome harbors the highest treeline tree species richness (152 species), which may reflect the fact that the majority of studies are available from the temperate regions of the world. The remaining 56 species are distributed within five other biomes, with the least in dry tropical and subarctic (four species each). Furthermore, currently 40 treeline tree species fall under different International Union for Conservation of Nature threat categories. We anticipate that our database will help advance research on macroecological, biogeographic, evolutionary, climate-change, and conservation aspects of the treeline on a global scale. The data are released under a Creative Commons Attribution 4.0 international license. Please cite this data paper when the data are reused.

Saharo-Sindian endemic flora of Egypt: critical checklist, floristic analysis, habitats, and phytogeographic distribution

The Saharo-Sindian region is characterized by savannas, semi-deserts, and hot deserts. This floristic region includes Morocco, Mauretania, Algeria, Libya, Egypt, Palestine, Kuwait, Saudi Arabia, Qatar, Bahrain, United Arab Emirates, Oman, Yemen, South of Jordan, Syria, Iraq, Afghanistan, Pakistan, in addition to the Sind region. The Sudano-Zambezian region, part of the Paleotropical Kingdom, and the Mediterranean and Irano-Turanian regions, included in the Holarctic Kingdom, share a significant portion of their flora with the studied region. This study initiates the examination of the Saharo-Sindian endemic plants occurring in Egypt. Its objectives include assessing the list of endemic plants within this floristic region, and studying various aspects such as: life forms, habitats, rarity forms, flowering times, dispersal types, and phytogeographical distribution. Twenty field trips were conducted from spring 2020 to September 2023, investigating different regions in Egypt. In addition, all the previous studies performed in the investigated area, scientific literature, and specimens from the region housed in different herbaria have been taken into consideration. The inventory of plants that are endemic to the Saharo-Sindian floristic region in Egypt comprises 126 plant taxa (109 species, 17 subspecies) distributed across 87 genera and 37 families. These endemics are found in 11 habitat types, with the most abundant occurrences observed in inland rocky areas (82 taxa) and temperate shrublands (57 taxa). Moreover, South Sinai stands out as the richest region for Saharo-Sindian endemics, hosting a remarkable 83 taxa, which constitute 65.9% of the total endemics. Among these, the chamaephytes group leads with 56 taxa, followed by the therophytes with 32 taxa. Pogonochores (45 taxa) are the most represented dispersal type. This study holds significant importance in evaluating a critical checklist of plants endemic to the Saharo-Sindian region in Egypt, contributing to our understanding of species diversity in regions facing severe anthropogenic disturbance. This list provides a foundational reference for future monitoring programs.

Global WaterPack - The development of global surface water over the past 20 years at daily temporal resolution

Open surface water across the globe is essential for many life forms and is an important source for human settlements, agriculture, and industry. The presence and variation in time and space is influenced by different natural conditions (e.g. climate, topography, geology) and human use (e.g. irrigation, flood protection). The information on the spatial and temporal distribution of open surface water is fundamental for many disciplines and is also required as an essential parameter for hydrological and climatological modelling. Here, we present a dataset derived from satellite earth observation, which is based on more than 6.3 million single MODIS products with a volume of approx. 300 TB. The resulting dataset reflects the situation of open surface water on a global scale for each day over the time period from 2003 to 2022 at a spatial resolution of 250 m. The dataset enables the analysis of the development of lake and reservoir surface areas, freezing cycles, and inundation areas.

Crosstalk between circadian clocks and pathogen niche.

Circadian rhythms are intrinsic 24-hour oscillations found in nearly all life forms. They orchestrate key physiological and behavioral processes, allowing anticipation and response to daily environmental changes. These rhythms manifest across entire organisms, in various organs, and through intricate molecular feedback loops that govern cellular oscillations. Recent studies describe circadian regulation of pathogens, including parasites, bacteria, viruses, and fungi, some of which have their own circadian rhythms while others are influenced by the rhythmic environment of hosts. Pathogens target specific tissues and organs within the host to optimize their replication. Diverse cellular compositions and the interplay among various cell types create unique microenvironments in different tissues, and distinctive organs have unique circadian biology. Hence, residing pathogens are exposed to cyclic conditions, which can profoundly impact host-pathogen interactions. This review explores the influence of circadian rhythms and mammalian tissue-specific interactions on the dynamics of pathogen-host relationships. Overall, this demonstrates the intricate interplay between the body's internal timekeeping system and its susceptibility to pathogens, which has implications for the future of infectious disease research and treatment.

Sustainable management of water resources in arid areas

Water is an essential resource for human survival, production and socio-economic development, essential for all forms of life, and essential for the maintenance of healthy ecosystems. Due to the continuous change of climate and the continuous growth of population, economy, region and other factors, water resources are becoming more and more scarce. In arid and semi-arid regions, the coupling and interaction between water resources security, energy security, food security and ecological security are becoming more complex, conflicts and contradictions are gradually emerging or intensifying, and uncertainty and risk levels are increasing. Water utilization and management methods are also becoming increasingly serious and complex, which requires new and innovative approaches to conserve and use water wisely. The sustainable management of water resources has always been the focus of research on water resources in the world, and there is much research on water resources management in major forums. This paper uses the method of review to analyze the relevant articles on water resources management, and puts forward more effective methods for sustainable water resources management, and provides suggestions for follow-up research on sustainable water resources management.

Dry grasslands and thorn-cushion communities of Armenia: a first syntaxonomic classification

Aim: To provide the first syntaxonomic, plot-based classification of the dry grasslands and thorn-cushion communities in Armenia. Study area: Armenia. Methods: We sampled 111 vegetation plots (10 m2) and recorded environmental and structural parameters. We collected additional 487 relevés from surrounding countries for a broad-scale comparison. We used modified TWINSPAN to derive a syntaxonomic classification system, whose units were then compared among each other regarding species composition, structure, site conditions and distribution. Results: The classification of Armenian vegetation plots resulted in a 12-cluster solution. Unsupervised classification of the broad-scale dataset yielded five main groups, which were used for the high-level syntaxonomic assignments of the Armenian data. We assigned about half of the plots of the Armenian dataset to the Festuco-Brometea, while the remaining represented a potential new class, preliminarily called “Ziziphora tenuior-Stipa arabica grasslands”. Most of the syntaxa below class level are new to science, therefore we provide formal descriptions of three orders (Plantagini atratae-Bromopsietalia variegatae, Onobrychido transcaucasicae-Stipetalia pulcherrimae, Cousinio brachypterae-Stipetalia arabicae), four alliances (Acantholimono caryophyllacei-Stipion holosericeae, Artemision fragrantis, Onobrychido michauxii-Stipion capillatae, Onobrychido transcaucasicae-Stipion pulcherrimae) and six associations. We found significant differences in the topographic, climatic and soil characteristics, and structural parameters, species life forms and distribution range types between the grassland types at different syntaxonomic levels. The mean species richness was 47.3 (vascular plants: 46.8, bryophytes: 0.4, lichens: 0.1). Conclusions: We found remarkable differences of the Armenian dry grasslands from the previously known units and described most of the higher syntaxa and all the associations as new to science. Our study provides arguments for a potential new class of Ziziphora tenuior-Stipa arabica grasslands separate both from the Euro-Siberian Festuco-Brometea and the Anatolian Astragalo-Brometea. Finally, we found plot scale richness of vascular plants clearly above the Palaearctic average of dry grasslands and that of non-vascular plants clearly below, which calls for further biodiversity analyses. Taxonomic reference: Euro+Med (2023) for vascular plants, Hodgetts et al. (2020) for bryophytes, Nimis et al. (2018) for lichens except for Xanthoparmelia camtschadalis (Ach.) Hale. Abbreviations: EDGG = Eurasian Dry Grassland Group; DCA = detrended correspondence analysis; ICPN = International Code of Phytosociological Nomenclature (Theurillat et al. 2021); TWINSPAN = two-way indicator species analysis.

Anthropogenic land-use change decreases pollination and male and female fitness in terrestrial flowering plants

Abstract Background and Aims The majority of the earth's land area is currently occupied by humans. Measuring how terrestrial plants reproduce in these pervasive environments is essential for understanding their long-term viability and their ability to adapt to changing environments. Methods We conducted hierarchical and phylogenetically-independent meta-analyses to assess the overall effects of anthropogenic land-use changes on pollination, and male and female fitness in terrestrial plants. Key Results We found negative global effects of land use change (i.e., mainly habitat loss and fragmentation) on pollination and on female and male fitness of terrestrial flowering plants. Negative effects were stronger in plants with self-incompatibility (SI) systems and pollinated by invertebrates, regardless of life form and sexual expression. Pollination and female fitness of pollination generalist and specialist plants were similarly negatively affected by land-use change, whereas male fitness of specialist plants showed no effects. Conclusions Our findings indicate that angiosperm populations remaining in fragmented habitats negatively affect pollination, and female and male fitness, which will likely decrease the recruitment, survival, and long-term viability of plant populations remaining in fragmented landscapes. We underline the main current gaps of knowledge for future research agendas and call out not only for a decrease in the current rates of land-use changes across the world but also to embark on active restoration efforts to increase the area and connectivity of remaining natural habitats.

Quantifying the role of termite decomposition in a mesic savanna

AbstractSavanna systems are among the most sensitive to future climate and land‐use change, yet we lack robust, direct quantifications of savanna carbon cycling. Together with fire, decomposition is the main process by which the carbon and nutrients are recycled and made available again to plants. Decomposition is largely mediated by microbes and soil invertebrates. Using a novel large‐scale termite suppression experiment, we quantify, for the first time, the relative contribution of microbes, termites, and other invertebrates to the decomposition of wood (fresh native and dry non‐native), dry dung, and grass in a mesic savanna. We found that termites were responsible for two thirds of the mass loss from dry wood and a third of the mass loss from fresh native wood, dry dung, and dry grass. Microbes were wholly responsible for the difference as there was no evidence of other invertebrates contributing to decomposition, even with fresh wood. Using multiple substrates in savanna decomposition studies is important where a mixture of contrasting life forms occur because both the rates of decomposition and the dominant agent varied considerably. In addition, including both a dry non‐native and fresh native wood cast light on possible explanatory variables such as wood density, green‐ness and the presence of bark, and the necessity of teasing these variables apart in future studies. Termites stand apart from all other insects in their impact on decomposition within savannas and should be acknowledged alongside microbes and fire as the primary agents of wood, grass, and dry dung turnover in global carbon models.

Investigating the Balance between Structural Conservation and Functional Flexibility in Photosystem I

Photosynthesis, as the primary source of energy for all life forms, plays a crucial role in maintaining the global balance of energy, entropy, and enthalpy in living organisms. Among its various building blocks, photosystem I (PSI) is responsible for light-driven electron transfer, crucial for generating cellular reducing power. PSI acts as a light-driven plastocyanin-ferredoxin oxidoreductase and is situated in the thylakoid membranes of cyanobacteria and the chloroplasts of eukaryotic photosynthetic organisms. Comprehending the structure and function of the photosynthetic machinery is essential for understanding its mode of action. New insights are offered into the structure and function of PSI and its associated light-harvesting proteins, with a specific focus on the remarkable structural conservation of the core complex and high plasticity of the peripheral light-harvesting complexes.

A Taxonomic Checklist of Insect Biodiversity in Loyola College Campus, Chennai, Tamil Nadu, India

Biodiversity, which refers to the entire array of life forms, genes, and ecosystems, was born as a result of the outcome of billions and billions of years of evolutionary development. In contrast to that, increasing the number of people and economy will impact biodiversity in the global level as it will not only destroy the ecosystems but also make them vulnerable to disruption. Preservation of biodiversity is undoubtedly one of the fundamental aspects that is necessary to keep species and genetic variations along with ecosystems. There is a large variety of insect species (more than half of all known life) and they are crucial for ecosystem functioning via pollination, nutrient recycling, and food web maintenance; However, they also act as vectors of diseases and pests. This research is focused on the insect diversity in Loyola College located in Chennai which was done through the Area Search Survey Method. Using a smartphone camera, the insects were imaged and then identified via iNaturalist. The reported data confirm the occurrence of various beetle classes, among which Lepidoptera is noted as the top order. The discussion delves into the ecological significance as well as economic influence of different insect groups which include services that they provide by way of pollination, pest control and so on. Awareness of insect biodiversity is important because of its role in ecosystem balance, agricultural stability, and human wellness.

Lighting the way: how the Vibrio fischeri model microbe reveals the complexity of Earth's "simplest" life forms.

Vibrio (Aliivibrio) fischeri's initial rise to fame derived from its alluring production of blue-green light. Subsequent studies to probe the mechanisms underlying this bioluminescence helped the field discover the phenomenon now known as quorum sensing. Orthologs of quorum-sensing regulators (i.e., LuxR and LuxI) originally identified in V. fischeri were subsequently uncovered in a plethora of bacterial species, and analogous pathways were found in yet others. Over the past three decades, the study of this microbe has greatly expanded to probe the unique role of V. fischeri as the exclusive symbiont of the light organ of the Hawaiian bobtail squid, Euprymna scolopes. Buoyed by this optically amenable host and by persistent and insightful researchers who have applied novel and cross-disciplinary approaches, V. fischeri has developed into a robust model for microbe-host associations. It has contributed to our understanding of how bacteria experience and respond to specific, often fluxing environmental conditions and the mechanisms by which bacteria impact the development of their host. It has also deepened our understanding of numerous microbial processes such as motility and chemotaxis, biofilm formation and dispersal, and bacterial competition, and of the relevance of specific bacterial genes in the context of colonizing an animal host. Parallels in these processes between this symbiont and bacteria studied as pathogens are readily apparent, demonstrating functional conservation across diverse associations and permitting a reinterpretation of "pathogenesis." Collectively, these advances built a foundation for microbiome studies and have positioned V. fischeri to continue to expand the frontiers of our understanding of the microbial world inside animals.

The Realist Discursive Study of Religion

Abstract Filip Rasmussen (2024) argues that the discursive study of religion is misunderstood when one assumes that it focuses only on discourse, ignoring material entities and forces. A discursive approach, he proposes, need not deny the existence or the effects of the material world, and so it is not in conflict with, for example, a critical realist approach to social theory that seeks to explain social behavior in terms of material mechanisms. Rasmussen’s synthesizing position gives us an opportunity to consider the relationship between the apparently rival theories of the discursive approach and critical realism – and, in particular, the relationship between discourse and the material realities in the world that do not depend on discourse for their existence or powers. My view is that Rasmussen is right and that a discursive approach combined with critical realism gives us the best account of forms of life, like religions, that combine discursive and nondiscursive elements. This paper therefore argues for the coherence of a realist discursive study of religion.

An assessment of nanotechnology-based interventions for cleaning up toxic heavy metal/metalloid-contaminated agroecosystems: Potentials and Issues

Heavy metals (HMs) are among the most dangerous environmental variables for a variety of life forms, including crops. Accumulation of HMs in consumables and their subsequent transmission to the food web are serious concerns for scientific communities and policy makers. The function of essential plant cellular macromolecules is substantially hampered by HMs, which eventually have a detrimental effect on agricultural yield. Among these HMs, three were considered, i.e., arsenic, cadmium, and chromium, in this review, from agro-ecosystem perspective. Compared with conventional plant growth regulators, the use of nanoparticles (NPs) is a relatively recent, successful, and promising method among the many methods employed to address or alleviate the toxicity of HMs. The ability of NPs to reduce HM mobility in soil, reduce HM availability, enhance the ability of the apoplastic barrier to prevent HM translocation inside the plant, strengthen the plant's antioxidant system by significantly enhancing the activities of many enzymatic and nonenzymatic antioxidants, and increase the generation of specialized metabolites together support the effectiveness of NPs as stress relievers. In this review article, to assess the efficacy of various NP types in ameliorating HM toxicity in plants, we adopted a ‘fusion approach’, in which a machine learning-based analysis was used to systematically highlight current research trends based on which an extensive literature survey is planned. A holistic assessment of HMs and NMs was subsequently carried out to highlight the future course of action(s).

Morphological responses of root hairs to changes in soil and climate depend on plant life form

IntroductionRoot hairs increase the surface area of a plant’s root system that is in contact with the soil, thus facilitating plant water and nutrient uptake. However, little is known about the characteristics of the root hairs of herbaceous and woody plants and their specific response patterns to biotic and abiotic variables from the perspective of resource acquisition strategies in the context of global change.MethodsHere, we analyzed 74 published case studies with 1074 observations of root hair traits to identify patterns of root hair length, density and diameter in relation to soil (e.g., soil pH, nutrient levels), growing environments (e.g., greenhouse, field) and climatic factors (e.g., air temperature), as well as genome size and plant age.ResultsRoot hairs were longer, denser and thicker in woody plants compared with herbaceous plants, and the length and diameter of root hairs in herbaceous plants increased with genome size. With increasing plant age, woody plants had significantly longer and thicker root hairs, while root hair density and diameter declined significantly for herbaceous plants. Soil-cultured plants had longer root hairs than solution-cultured plants. The length and density of root hairs were greater in greenhouse-cultured plants than in field-grown plants, and the latter had thicker root hairs than the former. As soil pH increased, root hair length increased but diameter decreased in woody plants, while root hair density increased in herbaceous plants. Increased soil total nitrogen (N) and potassium (K) significantly increased root hair length, density and diameter in herbaceous plants, while soil total N significantly decreased root hair density in woody plants. Root hair length increased significantly, while root hair density decreased significantly, with higher mean annual temperature and greater precipitation seasonality, while the opposite pattern was true for a wider annual temperature range.DiscussionOur findings emphasize the life-form-specific responses of root hairs to soil and climatic variables. These findings will help deepen our understanding of resource acquisition strategies and their mechanisms in different plant forms under global climate change.

Use of the Systemic Immune-Inflammation Index to Predict Treatment Efficacy in Patients with Bladder Pain Syndrome.

To determine the relationship between bladder pain syndrome (BPS) and systemic inflammatory index (SII) and to examine the impact of treatment protocols on it. Observational Study. Place and Duration of the Study: Department of Urology, Tekirdag Namik Kemal University, Tekirdag, Turkiye, from January 2017 to December 2022. A retrospective analysis was conducted on 30 BPS patients who underwent medical therapy. Upon diagnosis, the patients completed the king's health questionnaire (KHQ), beck depression questionnaire (BDQ), beck anxiety questionnaire (BAQ), and short form (SF-36) quality of life form. Peripheral blood SII was measured. After six months of regular therapy, the SII was recalculated when the patients completed the same forms again. The SII was compared between instances when patients reported more complaints, higher form scores, and instances when they reported fewer and lower scores. The patients had a mean age of 46.1 ± 13.6 years, with four males and 26 females. The mean follow-up duration was 76.3 ± 24.5 months. Five patients of KHQ subcategories showed statistically significant decreases following therapy (52 to 39.17, 66.66 to 54.16, 54.40 to 41.07, 75.55 to 58.14, and 60.55 to 40.47). All patients of SF-36 components increased (p = 779, p = 0.393, p = 0.007, p = 0.004, p = 0.008, p = 0.041, p = 0.010, and p = 0.767, respectively). BDQ and BAQ decreased after therapy (11.55 to 11.41 and 11.86 to 11.24, respectively). Lymphocyte count, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and SII decreased significantly (p = 0.001, 0.019, 0.002 and 0.039, respectively). SII, lymphocyte count, NLR, and PLR decreased after treatment, similar to BDQ and BAQ. SII is a simple and feasible method for evaluating the treatment efficacy of BPS. Bladder pain syndrome, Lymphocyte, Neutrophil, Systemic immune inflammation index, Platelet.

Aquaporins: Navigating the channels of cellular hydration

Aquaporin’s are water channel proteins found in all plasma membrane of various cells in all forms of life from bacteria to mammals. Around 17 mammalian aquaporin’s have been identified till date, which are classified into 3 subcategories based on their permeability. In normal physiology, AQPs serve as essential modulators of fluid transport and homeostasis in multiple organs and tissues. Altered expression of aquaporin’s is linked to numerous pathologies including fluid dysregulation, tumor metastasis and traumatic injury. Although some potential AQP modulators have been identified, challenges associated with the development of better modulators, include the suitability of the assay methods used to identify modulators and the drug ability of the target. The present review focus on aquaporin types and their altered conditions along with role of aquaporin’s in cancer and other diseases.

Evolutionary formation of melatonin and vitamin D in early life forms: insects take centre stage.

Melatonin, a product of tryptophan metabolism via serotonin, is a molecule with an indole backbone that is widely produced by bacteria, unicellular eukaryotic organisms, plants, fungi and all animal taxa. Aside from its role in the regulation of circadian rhythms, it has diverse biological actions including regulation of cytoprotective responses and other functions crucial for survival across different species. The latter properties are also shared by its metabolites including kynuric products generated by reactive oxygen species or phototransfomation induced by ultraviolet radiation. Vitamins D and related photoproducts originate from phototransformation of ∆5,7 sterols, of which 7-dehydrocholesterol and ergosterol are examples. Their ∆5,7 bonds in the B ring absorb solar ultraviolet radiation [290-315 nm, ultraviolet B (UVB) radiation] resulting in B ring opening to produce previtamin D, also referred to as a secosteroid. Once formed, previtamin D can either undergo thermal-induced isomerization to vitamin D or absorb UVB radiation to be transformed into photoproducts including lumisterol and tachysterol. Vitamin D, as well as the previtamin D photoproducts lumisterol and tachysterol, are hydroxylated by cyochrome P450 (CYP) enzymes to produce biologically active hydroxyderivatives. The best known of these is 1,25-dihydroxyvitamin D (1,25(OH)2D) for which the major function in vertebrates is regulation of calcium and phosphorus metabolism. Herein we review data on melatonin production and metabolism and discuss their functions in insects. We discuss production of previtamin D and vitamin D, and their photoproducts in fungi, plants and insects, as well as mechanisms for their enzymatic activation and suggest possible biological functions for them in these groups of organisms. For the detection of these secosteroids and their precursors and photoderivatives, as well as melatonin metabolites, we focus on honey produced by bees and on body extracts of Drosophila melanogaster. Common biological functions for melatonin derivatives and secosteroids such as cytoprotective and photoprotective actions in insects are discussed. We provide hypotheses for the photoproduction of other secosteroids and of kynuric metabolites of melatonin, based on the known photobiology of ∆5,7 sterols and of the indole ring, respectively. We also offer possible mechanisms of actions for these unique molecules and summarise differences and similarities of melatoninergic and secosteroidogenic pathways in diverse organisms including insects.

Rhizospheric bacteria from the Atacama Desert hyper-arid core: cultured community dynamics and plant growth promotion.

The Atacama Desert is the oldest and driest desert on Earth, encompassing great temperature variations, high ultraviolet radiation, drought, and high salinity, making it ideal for studying the limits of life and resistance strategies. It is also known for harboring a great biodiversity of adapted life forms. While desertification is increasing as a result of climate change and human activities, it is necessary to optimize soil and water usage, where stress-resistant crops are possible solutions. As many studies have revealed the great impact of the rhizobiome on plant growth efficiency and resistance to abiotic stress, we set up to explore the rhizospheric soils of Suaeda foliosa and Distichlis spicata desert plants. By culturing these soils and using 16S rRNA amplicon sequencing, we address community taxonomy composition dynamics, stability through time, and the ability to promote lettuce plant growth. The rhizospheric soil communities were dominated by the families Pseudomonadaceae, Bacillaceae, and Planococcaceae for S. foliosa and Porphyromonadaceae and Haloferacaceae for D. spicata. Nonetheless, the cultures were completely dominated by the Enterobacteriaceae family (up to 98%). Effectively, lettuce plants supplemented with the cultures showed greater size and biomass accumulation. We identified 12 candidates that could be responsible for these outcomes, of which 5 (Enterococcus, Pseudomonas, Klebsiella, Paenisporosarcina, and Ammoniphilus) were part of the built co-occurrence network. We aim to contribute to the efforts to characterize the microbial communities as key for the plant's survival in extreme environments and as a possible source of consortia with plant growth promotion traits aimed at agricultural applications.IMPORTANCEThe current scenario of climate change and desertification represents a series of incoming challenges for all living organisms. As the human population grows rapidly, so does the rising demand for food and natural resources; thus, it is necessary to make agriculture more efficient by optimizing soil and water usage, thus ensuring future food supplies. Particularly, the Atacama Desert (northern Chile) is considered the most arid place on Earth as a consequence of geological and climatic characteristics, such as the naturally low precipitation patterns and high temperatures, which makes it an ideal place to carry out research that seeks to aid agriculture in future conditions that are predicted to resemble these scenarios. Our main interest lies in utilizing microorganism consortia from plants thriving under extreme conditions, aiming to promote plant growth, improve crops, and render "unsuitable" soils farmable.

Between social cognition and material engagement: the cooperative body hypothesis

AbstractIn recent years, social cognition approaches to human evolution and Material Engagement Theory have offered new theoretical resources to advance our understanding of the prehistoric hominin mind. To date, however, these two approaches have developed largely in isolation from one another. I argue that there is a gap between social- and material-centred approaches, and that this is precisely the sociomateriality of the appearance of ancestral hominin bodies, which evolved under selective pressure to develop increasingly complex, cooperative sociality. To get this sociomaterial body in focus, I develop an esthesiological framework, appropriated from Merleau-Ponty (2003), for interpreting the expressive body in an evolutionary and comparative context. The guiding hypothesis of esthesiology is that before being rationality (social or material), “humanity is another corporeity” (Merleau-Ponty, 2003, p. 208). Esthesiology studies the appearance of the body and its sense organs as an intertwining locus of a sensing power (the ability to see, to touch, etc.) and a sensible character (the visible, touchable body). It is this dual-aspect character of the body that facilitates the most basic affective and sensorimotor modes of sociality. Examining these features from a comparative perspective, we find that the human body is distinctively suited to prosocial communication and cooperation: a more cooperative eye, an exposed and communicative skin. I thus propose a cooperative body hypothesis, by analogy with the cooperative eye hypothesis (Tomasello et al., 2007). Esthesiology provides a framework for integrating and interpreting a wide range of otherwise disconnected facts concerning human and nonhuman animal bodies, forms of life, cognition, and evolution, thereby bridging the gap between social cognition and material engagement perspectives. In doing so, however, it not only solves problems and proposes new directions of investigation, but also demands theoretical revisions from each.

The Evolutionary Transition of the RNA World to Obcells to Cellular-Based Life.

The obcell hypothesis is a proposed route for the RNA world to develop into a primitive cellular one. It posits that this transition began with the emergence of the proto-ribosome which enabled RNA to colonise the external surface of lipids by the synthesis of amphipathic peptidyl-RNAs. The obcell hypothesis also posits that the emergence of a predation-based ecosystem provided a selection mechanism for continued sophistication amongst early life forms. Here, I argue for this hypothesis owing to its significant explanatory power; it offers a rationale why a ribosome which initially was capable only of producing short non-coded peptides was advantageous and it forgoes issues related to maintaining a replicating RNA inside a lipid enclosure. I develop this model by proposing that the evolutionary selection for improved membrane anchors resulted in the emergence of primitive membrane pores which enabled obcells to gradually evolve into a cellular morphology. Moreover, I introduce a model of obcell production which advances that tRNAs developed from primers of the RNA world.