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lncRNAs are at the core of many regulatory processes and have also been recognized to be involved in various complex diseases. They affect gene regulation through direct interactions with RNA, DNA or proteins. Accordingly, lncRNAs structure is likely to be essential for their regulatory function. Point mutations, which manifest as SNPs (single nucleotide polymorphisms) in genome screens, can substantially alter their function and, subsequently, the expression of their down-stream regulated genes. To test the effect of SNPs on structure, we investigated lncRNAs associated with dilated cardiomyopathy. Among 322 human candidate lncRNAs we demonstrate first the significant association of a SNP located in lncRNA H19 using data from 1084 diseased and 751 control patients. H19 is generally highly expressed in the heart, with a complex expression pattern during heart development. Next, we used MFE (minimum free energy) folding to demonstrate a significant refolding in the secondary structure of this 861 nt long lncRNA. Since MFE folding may overlook the importance of sub-optimal structures, we showed that this refolding also manifests in the overall Boltzmann structure ensemble. There, the composition of structures is tremendously affected in their thermodynamic probabilities through the genetic variant. Finally, we confirmed these results experimentally, using SHAPE-Seq, corroborating that SNPs affecting such structures may explain hidden genetic variance not accounted for through genome wide association studies. Our results suggest that structural changes in lncRNAs, and lncRNA H19 in particular, affect regulatory processes and represent optimal targets for further in-depth studies probing their molecular interactions.

The Pennsylvanian (323.2–298.9 million years ago, Ma) is best-known for its peat-forming swamps. This unique, no-analog biome repeatedly dominated equatorial Euramerica during the glacial intervals of the glacial-interglacial cycles of the Late Paleozoic Ice Age (LPIA, ∼335 to 260 Ma). During this period, Earth’s landmasses had just recently aggregated into the supercontinent Pangea, and Euramerica was a mostly flat craton spread across the equator. Glacial intervals saw massive amounts of ice covering the south pole. Interglacials saw increases in eustatic sea level coincident with melting ice. In Euramerica, glacials meant everwet rather than monsoonal conditions in the intertropics, which allowed peat swamp vegetation to expand beyond wet basins and dominate the flat landscape. By contrast, interglacials came with more seasonal and therefore drier overall conditions. These changes in sea level and precipitation led to shrinkage of the biome, and survival of communities in refugia. Each subsequent glacial interval saw re-expansion of the swamps. Similarities and changes in swamp vegetation can be well-tracked from one glacial to the next, due to the exceptional paleobotanical record of this period. Despite the wet conditions that gave rise to Pennsylvanian peat swamps, this biome is known to have regularly experienced wildfires. Although these paleowildfires are well documented in the sedimentary record as fossilized charcoal, our knowledge of their ecological role and evolutionary impacts is limited. In this dissertation, I utilize one of the largest paleobotanical datasets in existence to investigate patterns in peat swamp plant diversity and community composition in response to changes in climate, and to investigate the role that paleowildfires played in this unique biome.In chapter one, I examine the research history and structure of the Pennsylvanian plant fossil record. Reconstructions of Pennsylvanian peat-forming communities are, for a large part, based on quantitative microscopic analysis of acetate peels of carbonate nodules—so-called “coal balls”—which three-dimensionally preserve plant litter from these swamps. Extensive coal ball analysis was carried out by the former Phillips lab of the University of Illinois, Urbana-Champaign, primarily during the 1970s and 80s. The origin of the Phillips Coal Ball Collection (PCBC) dataset is closely tied to the early days of scientific computing. Until recently, most of the collection data only existed in formats rarely used in the present day, specifically, continuous-form IBM 360 mainframe computer printouts and first-generation 8-inch floppy disks. In this chapter, I outline the process of “re-digitizing” these data, including the complex task of reading the floppy disks, attempts at automated transcription of the paper datasheets with Optical Character Recognition, and the ultimate setup for high-throughput photography and transcription. I describe the integration of undergraduate and community scientist researchers, outline recommended practices and potential pitfalls, and highlight the need for coordinated efforts to preserve scientific data from the early computational era in the near future. This work yielded an “occurrence-type” dataset with over 450,000 plant fossil observations. Spatially, this dataset spans modern-day North America, Europe, North Africa, and East Asia. Temporally, it covers the 24-million-year Pennsylvanian period and the latest Permian. My re-digitization work with these data paved the way for all of the analyses carried out in chapters two and three.Chapter two focuses on diversity dynamics in the Pennsylvanian, with a focus on the interval around the Middle-Late Pennsylvanian transition. This transition is well known for the Carboniferous Rainforest Collapse (CRC), a major floral turnover evidenced by and best known for the loss of all but one genus of arborescent lycopods. However, my analyses of the PCBC data indicate the CRC should not be considered a strict boundary phenomenon. I recover increased per-capita extinction rates and decreased per-capita origination rates for plant genera from all major taxonomic groups across multiple glacial-interglacial cycles starting before the Middle-Late Pennsylvanian boundary. Changes in ecological structuring—as indicated by dominance-diversity curves, evenness and ecological dissimilarity values, and Detrended Correspondence Analyses based on genus abundance at individual coal ball peels—also begin prior to the boundary. Furthermore, forward survivorship curves additionally hint at a more protracted decline in genus diversity. Transition to Late Pennsylvanian floral regimes beginning in the late Middle Pennsylvanian has been previously commented upon, and it has been suggested that the Late Pennsylvanian aridification started in the late Middle Pennsylvanian. If increased aridification and concomitant shifts in CO2 and O2 levels were drivers of the CRC, an earlier start would follow logically. Although changes in diversity dynamics predate the Middle-Late Pennsylvanian transition, the most dramatic decrease in lycopod domination—and with that a shortening of the ecological gradient and physical structure of the plant communities—occurs at the boundary. Lastly, in this chapter I discuss a potential ecosystem engineering effect by which arborescent lycopods may have helped create their own suitable habitat. I propose a hypothesis: that a breakdown of this effect, via the crossing of some ecological threshold, may have been a driver of the CRC.For my final chapter, I further investigate the ecology of this time period, focusing on paleofire. In particular, I use the PCBC dataset to explore the influence of wildfires on peat swamp communities. The Pennsylvanian has long been of interest to the niche field of paleofire ecology, due to its abundant charcoal record, as well the fact that the numerous paleoatmospheric oxygen reconstructions recover it as a “hyperoxic” interval. Hyperoxic (or “superambient”) oxygen levels refer to oxygen levels above the Present Atmospheric Level of 21%. Experimental work has shown that fire behaves very differently under such conditions, with potentially increased burn probability, burn duration, and spread rate. I set out to apply methods from neontological wildfire ecology to the PCBC dataset. Specifically, I investigated the distribution and relative abundance of paleofuel sources to determine which tissues, organs, and taxa contributed to paleowildfires, and to study how those fires behaved. I find that between-coal-seam charcoal variability is high, and that any long-term temporal shifts—if present—are therefore obfuscated. However, some patterns in charcoal abundance clearly hold across space and time. Wood, cortex, and periderm tissues are consistently over-represented as charcoal, when compared to other tissues and organs, while reproductive parts and foliage are consistently under-represented. Pteridosperms, which include the proposedly fire-prone medullosans, are found to be no more frequently charcoalified than any of the other major taxonomic groups present. The tree ferns—who dominate peat floras after the CRC—are an exception: their charred remains do not contain substantially fewer reproductive structures (which are leaf-born) and foliage seems overrepresented in tree fern charcoal rather wood, cortex, and periderm tissues, as in the other major plant groups. I use these results to try to make inferences about the types of fires present in these swamps, with a particular goal of evaluating the presence/absence and frequency of crown fires—intense fires that burn through the canopies of plant communities. Finally, I explore how complex interactions between hyperoxic combustion, no-analog plant communities, and under-explored taphonomic factors complicate attempts to reconstruct Pennsylvanian fire types and regimes.

Human impact is noticeable around the globe, indicating that a new era might have begun: the Anthropocene. Continuing human activities, including land‐use changes, introduction of non‐native species and rapid climate change, are altering the distributions of countless species, often giving rise to human‐mediated hybridization events. While the interbreeding of different populations or species can have detrimental effects, such as genetic extinction, it can be beneficial in terms of adaptive introgression or an increase in genetic diversity. In this paper, I first review the different mechanisms and outcomes of anthropogenic hybridization based on literature from the last five years (2016–2020). The most common mechanisms leading to the interbreeding of previously isolated taxa include habitat change (51% of the studies) and introduction of non‐native species (34% intentional and 19% unintentional). These human‐induced hybridization events most often result in introgression (80%). The high incidence of genetic exchange between the hybridizing taxa indicates that the application of a genic view of speciation (and introgression) can provide crucial insights on how to address hybridization events in the Anthropocene. This perspective considers the genome as a dynamic collection of genetic loci with distinct evolutionary histories, giving rise to a heterogenous genomic landscape in terms of genetic differentiation and introgression. First, understanding this genomic landscape can lead to a better selection of diagnostic genetic markers to characterize hybrid populations. Second, describing how introgression patterns vary across the genome can help to predict the likelihood of negative processes, such as demographic and genetic swamping, as well as positive outcomes, such as adaptive introgression. It is especially important to not only quantify how much genetic material introgressed, but also what has been exchanged. Third, comparing introgression patterns in pre‐Anthropocene hybridization events with current human‐induced cases might provide novel insights into the likelihood of genetic swamping or species collapse during an anthropogenic hybridization event. However, this comparative approach remains to be tested before it can be applied in practice. Finally, the genic view of introgression can be combined with conservation genomic studies to determine the legal status of hybrids and take appropriate measures to manage anthropogenic hybridization events. The interplay between evolutionary and conservation genomics will result in the constant exchange of ideas between these fields which will not only improve our knowledge on the origin of species, but also how to conserve and protect them.

Life in the era of biotechnology opens up opportunities but also poses challenges related to our values and questions regarding the way we want to see coexistence on our planet, which is inhabited by many species. The parasite is our case study and an interesting concept that we inherit from biology but which is also addressed in humanism and philosophy. As humans, we commonly understand the concept of a parasite as a negative one that suggests someone or something which benefits at our expense. Howev-er, French philosopher Michel Serres had a different view of the parasite. According to him, the parasite is based on relationships between different entities, and there is often noise in these relationships. Serres refers to biologist Henri Atlan, who has argued that said noise forces the system to reorganize itself in a way that incorporates the noise into the complex system. The idea of noise as an integrated part of the system is quite far from today’s thought processes with the develop-ment of bio/ technology that typically aims to be noiseless and error-free and have aesthetically attractive results. Therefore, although parasites are often associated with terms such as inhospitable, undesirable, and disgusting and are seen to be located outside of art and technology, in this paper, we argue that the concept of something parasitical is tightly inter-twined with our contemporary biotechnical lives. The article relates Serres’ parasitic thinking to an artistic mediation of the biological parasite: the tick.

Plant phylogeny sometimes predicts interspecific variation in pollinator composition better than gross floral features, and its predictive value seems to differ among major groups of insect pollinators. Pollination by beetles exhibits the strongest phylogenetic signal and the strongest phylogenetic conservatism, which is particularly intriguing given that beetles were probably the pollinators of early angiosperms. We examine in this paper the relationship between plant phylogeny and flower visitation by nitidulid beetles (Coleoptera: Nitidulidae), an old monophyletic group of flower specialists and pollinators of gymnosperms and angiosperms. Using quantitative data on pollinator composition for 251 plant species (belonging to 167 genera in 46 families) from well-preserved Mediterranean montane habitats from southeastern Spain, the following questions were addressed: Is pollination by nitidulids correlated with plant phylogeny in the large species sample studied, and if it does, which are the relative importances of plant phylogeny, floral characteristics, and environmental features as predictors of nitidulid pollination in the plant assemblage studied ? Nitidulids were recorded in flowers of 25% of the plant species considered. Their distribution was significantly related to plant phylogeny, being clustered on certain lineages (Ranunculales, Malvales, Rosales, Asterales) and remarkably absent from others (e.g., Fabales, Lamiales). None of the environmental (habitat type, elevation) or macroscopic floral features considered (perianth type and color, flower mass) predicted nitidulid visitation after statistically accounting for the effect of plant phylogeny. We theorize that nitidulid beetles use characters of plants that track plant phylogeny at least as deep as the early radiation of the eudicots, imaginably characters such as the chemical signatures of pollen

This paper provides an updated classification of the Kingdom Fungi (including fossil fungi) and fungus-like taxa. Five-hundred and twenty-three (535) notes are provided for newly introduced taxa and for changes that have been made since the previous outline. In the discussion, the latest taxonomic changes in Basidiomycota are provided and the classification of Mycosphaerellales are broadly discussed. Genera listed in Mycosphaerellaceae have been confirmed by DNA sequence analyses, while doubtful genera (DNA sequences being unavailable but traditionally accommodated in Mycosphaerellaceae) are listed in the discussion. Problematic genera in Glomeromycota are also discussed based on phylogenetic results., National Natural Science Foundation of China (NSFC) NSFC 31950410558 NSFC 31760013 32100011, Department of Science and Technology of Yunnan Province 2018FB050, State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Medical University FAMP201906K, Science and Technology Department of Guizhou Province QKHRCPT[2017] 5101, High-Level Talent Recruitment Plan of Yunnan Province ("Young Talents" Program), Chiang Mai University, Croatian Science Foundation HRZZ-IP-2018-01-1736 HRZZ-2018-09-7081, LOEWE initiative of the government of Hessen, Distinguished Scientist Fellowship (DSFP), King Saud University, Kingdom of Saudi Arabia, CAS President's International Fellowship Initiative (PIFI) 2020PB0115 2020PC0009 2018PC0006, National Science Centre, Poland 2017/25/B/NZ8/00473, International Postdoctoral Exchange Fellowship Program Y9180822S1, China Postdoctoral Science Foundation, Yunnan Human Resources, and Social Security Department Foundation, National Natural Science Foundation of China (NSFC) 31750110478, China Postdoctoral Science Foundation 2021M693361, Portuguese Foundation for Science and Technology, European Commission UIDB/04046/2020 UIDP/04046/2020, High-Level Talent Recruitment Plan of Yunnan Province ("High-End Foreign Experts" Program)

Elegant terns Thalasseus elegans breed in a very limited area of the northern Gulf of California and the Pacific coast of southern California, with up to 95% (mean 78%, 1991–2014, Perez et al., 2020) of the population nesting on Isla Rasa in the northern Gulf of California. On Isla Rasa, the primary nesting colony, elegant terns suffered predation by rodents which raised the possibility of population extinction, with a substantial proportion of the world population nesting on this single island. Because of this threat, rodents were successfully removed from Isla Rasa in 1995. The removal of rodents from Isla Rasa led to a near immediate increase in the population of elegant terns. That increase was associated with a changing pattern in dispersal by the terns, including extraordinary movements to the Gulf of Mexico, the Atlantic coast of the United States north to Massachusetts, and, remarkably, to western Europe. A few elegant terns successfully bred at these European localities during 2009 to the present. In this paper we use this exceptional example of long-distance dispersal to illustrate how rapid population growth during ∼ 1995 to present can lead to successful colonization of remote sites through repeated instances of vagrancy. We tested four Hypotheses that together support the idea that the growing population of elegant terns has produced increasing numbers of young, and these young have spread, through the mechanism of vagrancy, to the Pacific Northwest, the east coast of the United States, and western Europe. Our Hypotheses are: (1) The nesting population of elegant terns within their core nesting range has increased since removal of rodents from Isla Rasa; (2) Occurrence of vagrant elegant terns in the Pacific Northwest is driven by population growth within the core breeding range. (3) Occurrence of vagrant elegant terns at the east coast of the United States is driven by population growth within the core breeding range. (4) Occurrence and colonization of western Europe by elegant terns is driven by nesting population size within the core breeding range. Corollaries of these Hypotheses are, (i) that there is a time lag in occurrence of vagrants at each of these areas, based on increasing distance from the core breeding range and (ii) the number of vagrants in any given year is also related to sea surface temperature (SST), as expressed by Oceanic Niño Index, a proxy for food resource levels. Generally we found strong statistical support for each of these Hypotheses; an exception was for the occurrence of elegant terns in the Pacific Northwest, which initially occurred following El Niño events (low food supply) and profound breeding failure, but later corresponding to cold water years with high breeding success. We use elegant terns, exceptional for the highly restricted breeding range and sustained population growth over 25 years, to illustrate how growing populations may colonize very distant habitats through repeated instances of vagrancy.

The encapsulation of genetic material inside compartments together with the creation and sustenance of functionally diverse internal components are likely to have been key steps in the formation of ‘live’, replicating protocells in an RNA world. Several experiments have shown that RNA encapsulated inside lipid vesicles can lead to vesicular growth and division through physical processes alone. Replication of RNA inside such vesicles can produce a large number of RNA strands. Yet, the impact of such replication processes on the emergence of the first ribozymes inside such protocells and on the subsequent evolution of the protocell population remains an open question. In this paper, we present a model for the evolution of protocells with functionally diverse ribozymes. Distinct ribozymes can be created with small probabilities during the error-prone RNA replication process via the rolling circle mechanism. We identify the conditions that can synergistically enhance the number of different ribozymes inside a protocell and allow functionally diverse protocells containing multiple ribozymes to dominate the population. Our work demonstrates the existence of an effective pathway towards increasing complexity of protocells that might have eventually led to the origin of life in an RNA world.

Background The animal phylum Cnidaria consists of six classes or subphyla: Hydrozoa, Scyphozoa, Cubozoa, Staurozoa, Anthozoa, and Endocnidozoa. Cnidarians have an early evolutionary origin, diverging before the emergence of the Bilateria. Extant members from this phylum, therefore, are important resources for understanding the evolution of the nervous system. Cnidarian nervous systems are strongly peptidergic. Using genomics, we have recently shown that three neuropeptide families (the X1PRX2amides, GRFamides, and GLWamides) are wide-spread in four (Scyphozoa, Cubozoa, Staurozoa, Anthozoa) out of six cnidarian classes or subphyla, suggesting that these three neuropeptide families emerged in the common cnidarian ancestor. In the current paper, we analyze the remaining cnidarian class, Hydrozoa, and the subphylum Endocnidozoa, to make firm conclusions about the evolution of neuropeptide genes in Cnidaria. Results We analyzed sixteen hydrozoan species with a sequenced genome or transcriptome, using a recently developed software program for discovering neuropeptide genes. These species belonged to various hydrozoan subclasses and orders, among them the laboratory models Hydra, Hydractinia, and Clytia. We found that each species contained three to five neuropeptide families. A common feature for all hydrozoans was that they contained genes coding for (i) X1PRX2amide peptides, (ii) GRFamide peptides, and (iii) GLWamide peptides. These results support our previous conclusions that these three neuropeptide families evolved early in evolution. In addition to these three neuropeptide families, hydrozoans expressed up to two other neuropeptide gene families, which, however, were only occurring in certain animal groups. Endocnidozoa (Myxozoa) are microscopically small endoparasites, which are strongly reduced. For long, it was unknown to which phylum these parasites belonged, but recently they have been associated with cnidarians. We analyzed nine endocnidozoan species and found that two of them (Polypodium hydriforme and Buddenbrockia plumatellae) expressed neuropeptide genes. These genes coded for neuropeptides belonging to the GRFamide and GLWamide families with structures closely resembling them from hydrozoans. Conclusions We found X1PRX2amide, GRFamide, and GLWamide peptides in all species belonging to the Hydrozoa, confirming that these peptides originated in the common cnidarian ancestor. In addition, we discovered GRFamide and GLWamide peptide genes in some members of the Endocnidozoa, thereby linking these parasites to Hydrozoa.

The conserved adapter protein Scribble (Scrib) plays essential roles in a variety of cellular processes, including polarity establishment, proliferation, and directed cell migration. While the mechanisms through which Scrib promotes epithelial polarity are beginning to be unraveled, its roles in other cellular processes including cell migration remain enigmatic. In C. elegans, the Scrib ortholog LET-413 is essential for apical–basal polarization and junction formation in embryonic epithelia. However, whether LET-413 is required for postembryonic development or plays a role in migratory events is not known. Here, we use inducible protein degradation to investigate the functioning of LET-413 in larval epithelia. We find that LET-413 is essential in the epidermal epithelium for growth, viability, and junction maintenance. In addition, we identify a novel role for LET-413 in the polarized outgrowth of the epidermal seam cells. These stem cell-like epithelial cells extend anterior and posterior directed apical protrusions in each larval stage to reconnect to their neighbors. We show that the role of LET-413 in seam cell outgrowth is likely mediated largely by the junctional component DLG-1 discs large, which we demonstrate is also essential for directed outgrowth of the seam cells. Our data uncover multiple essential functions for LET-413 in larval development and show that the polarized outgrowth of the epithelial seam cells is controlled by LET-413 Scribble and DLG-1 Discs large., Author summary Most cells in multicellular organisms are organized along a directional axis of cell polarity. One protein that is important for this polarized organization is the conserved polarity regulator Scribble. This protein has several functions, including forming the basolateral domains of cells, promoting the formation of cell junctions, and promoting cell migration. How Scribble performs these functions is not fully understood. In this paper we study the role of Scribble during larval development of the small nematode Caenorhabditis elegans using an inducible protein degradation system. We show that Scribble, called LET-413 in C. elegans, is essential in the epidermal epithelium for animal development, as depletion of LET-413 in only this tissue blocks growth. We also demonstrate that LET-413 is required for the polarized outgrowth of an epithelial cell type called the seam cells, a process resembling cell migration. Finally, we show that one major function of LET-413 in seam cell outgrowth is the localization of the junctional component Discs large (DLG-1), which we demonstrate is also essential for this process. Our data thus uncover multiple essential functions for LET-413 in larval development and provide new insights into how the directional outgrowth of epithelial seam cells is controlled.

The present paper focuses on plant diversity fluctuations within three ecosystems from a volcanic slope in the sequence analytical context of three superimposed cyclicities. This analysis was possible thanks to the isotopic age evaluation of the volcanic Merangin section that bracketed the Mengkarang Formation on West Sumatra between 296.77 ± 0.04 and 296.14 ± 0.09 Ma (Asselian, Lower Permian). The Merangin section consists of a 490 m long fining and thinning tuffaceous aggregational sequence composed of eight short-eccentricity fining and thinning upwards parasequences. The palaeoflora along the sequence varies from tropical wet taxa, comprising cordaitalean and ferns, to mesic-xeric taxa, typified by seed ferns and early conifers. Herein the palaeofloral content of 14 consecutive lahars from a single volcanic accretion wedge in the seventh parasequence is described in detail. It displays a gradual increase in the ratios of (seed) ferns (Macralethopteris hallei, Sphenopteris sp. and gigantopterids) and early conifers (Dicranophyllum molle, Tobleria bicuspis), reaching a 100% in the 6th bed, and returning to 100% cordaitalean and ferns. The high ratio of seed ferns and early conifers in the 6th lahar is interpreted as reflecting a temporary lowering of the tree line caused by a glacial maximum from a high order cycle (obliquity or precession), superimposed on a short-eccentricity cycle, which in turn is superimposed on our third-order cycle palaeofloral transition described earlier for the whole sequence. Along this lower Permian section from the low latitudes from the Palaeotethys, glacial-interglacial cycles are seen to affect the fluctuations of the vegetation line in a chiefly similar way as during the Quaternary. The diversity fluctuations for three ecosystems (wetlands, lower and upper slope) are modelled for two of the three or more superimposed cycles. Emphasis is put on the appearance of a glacial palaeoflora on top of the sequence.

Fruit flies are a well-known invasive species, and climate-based risk modeling is used to inform risk analysis of these pests. However, such research tends to focus on already well-known invasive species. This paper illustrates that appropriate risk modeling can also provide valuable insights for flies which are not yet “on the radar.”Carpomya pardalinais a locally important cucurbit-infesting fruit fly of western and central Asia, but it may present a risk to other temperate countries where melons are grown. MaxEnt models were used to map the risk area for this species under historical and future climate conditions averaged from three global climate models under two shared socio-economic pathways in 2030 and 2070 from higher climate sensitivity models based on the upcoming 2021 IPCC sixth assessment report. The results showed that a total of 47.64% of the world’s land mass is climatically suitable for the fly; it could establish widely around the globe both under current and future climates with host availability. Our MaxEnt modeling highlights particularly that Western China, Russia, and other European countries should pay attention to this currently lesser-known melon fly and the melons exported from the present countries. The current and expanding melon trade could offer direct invasion pathways to those regions. While this study offers specific risk information onC. pardalina, it also illustrates the value of applying climate-based distribution modeling to species with limited geographic distributions.

Serotonin is a well-known neurotransmitter and neurohormone regulating mood, sleep, feeding, and learning in high organisms. Serotonin also affects the embryonic events related to neurogenesis and maturation of hormonal systems, the underlying organism adaptation to a changing environment. Such serotonin-based mother-to-embryo signaling is realized via direct interactions in case of internal fertilization and embryonic development inside the mother body. However, the possibility of such signaling is less obvious in organisms with the ancestral type of embryogenesis and embryo development within the egg, outside the mother body. Our data, based on the investigation of freshwater gastropod molluscs (Lymnaea and Helisoma), demonstrated a correlation between seasonal variations of serotonin content within the female reproductive system, and developmental patterns and the behavioral characteristics of progeny. The direct action of serotonin via posttranslational protein modification—serotonylation—during early development, as well as classical receptor-mediated effects, underlies such serotonin-modulated developmental changes. In the present paper, I will shortly overview our results on freshwater molluscs and parallel the experimental data with the living strategy of these species occupying almost all Holarctic regions.

Over 50 years ago, seminal papers by Armstrong and McGehee showed how temporal fluctuations in resources or environmental conditions could permit coexistence of two species. Such coexistence results from non-linearities in the way resource supply translates into fitness. These non-linearities reflect trade-offs where one species benefits more than the other during good periods and suffers more (or does less well) than the other during less good periods, be the periods stochastic or seasonal. Since, coexistence based on fluctuating conditions has been explored under the guises of “grazers” and “diggers”, variance partitioning, and as the storage effect. Here we focus on two phenotypes, “cream skimmers” and “crumb pickers”, the former having the advantage under richer times and the latter on less rich times. Examples of coexistence based on fluctuations of resources have been identified in diverse ecosystems in nature. Examples include hummingbirds and bees; large desert rodents versus small; annual versus perennial plants; various intertidal algal feeders, desert annual plants, and plankton; and more. In nature, richer and poorer times, with regular or stochastic appearances, are the norm. These varying fat and lean times occur on many scales of time and space. Rich times and poor times also appear to be the norm in cancer ecosystems. Within tumors, nutrient availability, oxygen, and pH can fluctuate stochastically or periodically, with swings occurring over seconds to minutes to hours. Despite considerable interest in tumor heterogeneity and how it promotes the coexistence of different cancer cell types, the effects of fluctuating resource availability have not yet been explored for cancer. Here, we 1) examine four types of trade-offs that can promote coexistence of phenotypes that do relatively better in richer versus in poorer times, 2) establish that the conditions in tumors are conducive for this mechanism, 3) propose and empirically explore biomarkers indicative of the two phenotypes (HIF-1; GLUT-1; CA IX; CA XII), 4) and compare cream skimmer and crumb picker biology and ecology in nature and cancer to provide cross-disciplinary insights into this interesting, and, we argue, likely very common, mechanism of coexistence.

Military installations are valuable in global biodiversity conservation as they secure representative ecosystems from land conversion and protect many threatened or endangered species. Selecting suitable areas for biodiversity conservation within military installations is a challenging problem as this must not impede military training activities. The issue gets more complicated when considering multiple cohabiting species in a metacommunity with interdependency between targeted species. In this paper, we present an example for the conservation of two cohabiting species, Gopher Tortoise (GT) and Gopher Frog (GF), located within the boundaries of a military installation, Fort Stewart, Georgia, USA. The GF depends on both locations of GT habitat (burrows) and ephemeral vernal ponds (for breeding). By extending our previous work, we developed a model that identifies the cost-efficient areas for the conservation of these two species while taking into account the dependency of GF on GT burrows. The model designs a specified number of conservation areas for the two species, where each GF conservation area covers an adequate number of vernal ponds for the GFs to accommodate their reproduction, and each GT conservation area provides adequate habitat quality to sustain a viable GT population. The model also requires each GF site to be located close to GT sites so that the GFs could find refuge after they leave the water. We measure the conservation cost as the total distance of selected sites to the main roads in the military installation. We achieve contiguity of each conservation area by selecting sites that are adjacent to a central site of the conservation area to ensure undisrupted travel for both the GFs and the GTs. Using the model, we generated alternative configurations of conservation areas that could be considered by the land managers of Fort Stewart. Our methods are general and can be applied to other reserve site selection and land management problems with cohabiting interrelated species.