cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5683/sp2/xypk7f
title: Data from: The effect of range overlap on ecological niche divergence depends on spatial scale in monkeyflowers

description: AbstractPatterns of niche divergence and geographical range overlap of closely related species provide insights into the evolutionary dynamics of ecological niches. When ranges overlap, shared selective pressures may preserve niche similarity along coarse‐scale macrohabitat axes (e.g., bioclimates). Alternatively, competitive interactions may drive greater divergence along local‐scale microhabitat axes (e.g., micro‐topographical features). We tested these hypotheses in 16 species pairs of western North American monkeyflowers (Erythranthe and Diplacus, formerly Mimulus) with species’ niches, geographic ranges and a robust phylogeny. We found that macrohabitat niche divergence decreased with increasing range overlap, consistent with convergent selection operating at a coarse scale. No significant relationship was detected for microhabitat niches. Additionally, niche divergence was greater for young pairs along all macrohabitat niche axes, but greater for old pairs along one microhabitat axis related to vegetation cover. For a subset of species pairs with partially overlapping ranges, greater microhabitat divergence was detected in sympatry than in allopatry for at least one niche axis for three pairs, consistent with character displacement in sympatry. Thus, coarse‐ and local‐scale niche divergence show dissimilar patterns in relation to range overlap and evolutionary time, perhaps because the relative importance of convergent versus divergent selection depends on spatial scale.
DOI: 10.5683/sp2/gkxlun
title: Data from: The effects of food web structure on ecosystem function exceeds those of precipitation

description: AbstractEcosystems are being stressed by climate change, but few studies have tested food web responses to changes in precipitation patterns and the consequences to ecosystem function. Fewer still have considered whether results from one geographic region can be applied to other regions, given the degree of community change over large biogeographic gradients. We assembled, in one field site, three types of macroinvertebrate communities within water-filled bromeliads. Two represented food webs containing both a fast filter feeder-microbial and slow detritivore energy channels found in Costa Rica and Puerto Rico, and one represented the structurally simpler food webs in French Guiana, which only contained the fast filter feeder-microbial channel. We manipulated the amount and distribution of rain entering bromeliads, and examined how food web structure mediated ecosystem responses to changes in the quantity and temporal distribution of precipitation. Food web structure affected the survival of functional groups in general, and ecosystem functions such as decomposition and the production of fine particulate organic matter. Ecosystem processes were more affected by decreased precipitation than were the abundance of microorganisms and metazoans. In our experiments, the sensitivity of the ecosystem to precipitation change was primarily revealed in the food web dominated by the single filter feeder-microbial channel because other top-down and bottom-up processes were weak or absent. Our results show stronger effects of food web structure than precipitation change per se on the functioning of bromeliad ecosystems. Consequently, we predict that ecosystem function in bromeliads throughout the Americas will be more sensitive to changes in the distribution of species, rather than to the direct effects caused by changes in precipitation.
DOI: 10.5683/sp2/qy337w
title: Data from: The evolution of sex chromosomes in organisms with separate haploid sexes

description: AbstractThe evolution of dimorphic sex chromosomes is driven largely by the evolution of reduced recombination and the subsequent accumulation of deleterious mutations. While these processes are increasingly well understood in diploid organisms, the evolution of dimorphic sex chromosomes in haploid organisms (U/V) has been virtually unstudied theoretically. We analyze a model to investigate the evolution of linkage between fitness loci and the sex-determining region in U/V species. In a second step, we test how prone non-recombining regions are to degeneration due to accumulation of deleterious mutations. Our modeling predicts that the decay of recombination on the sex chromosomes and the addition of strata via fusions will be just as much a part of the evolution of haploid sex chromosomes as in diploid sex chromosome systems. Reduced recombination is broadly favored, as long as there is some fitness difference between haploid males and females. The degeneration of the sex-determining region due to the accumulation of deleterious mutations is expected to be slower in haploid organisms because of the absence of masking. Nevertheless, balancing selection often drives greater differentiation between the U/V sex chromosomes than in X/Y and Z/W systems. We summarize empirical evidence for haploid sex chromosome evolution and discuss our predictions in light of these findings.
DOI: 10.5683/sp2/ffowxi
title: Data from: The evolutionary history of dogs in the Americas

description: AbstractDogs were present in the Americas prior to the arrival of European colonists, but the origin and fate of these pre-contact dogs are largely unknown. We sequenced 71 mitochondrial and seven nuclear genomes from ancient North American and Siberian dogs spanning ~9,000 years. Our analysis indicates that American dogs were not domesticated from North American wolves. Instead, American dogs form a monophyletic lineage that likely originated in Siberia and dispersed into the Americas alongside people. After the arrival of Europeans, native American dogs almost completely disappeared, leaving a minimal genetic legacy in modern dog populations. Remarkably, the closest detectable extant lineage to pre-contact American dogs is the canine transmissible venereal tumor, a contagious cancer clone derived from an individual dog that lived up to 8,000 years ago.
DOI: 10.5683/sp2/gwslbe
title: Data from: The evolutionary history of ferns inferred from 25 low-copy nuclear genes

description: AbstractPremise of the study: Understanding fern (monilophyte) phylogeny and its evolutionary timescale is critical for broad investigations of the evolution of land plants, and for providing the point of comparison necessary for studying the evolution of the fern sister group, seed plants. Molecular phylogenetic investigations have revolutionized our understanding of fern phylogeny, however, to date, these studies have relied almost exclusively on plastid data. Methods: Here we take a curated phylogenomics approach to infer the first broad fern phylogeny from multiple nuclear loci, by combining broad taxon sampling (73 ferns and 12 outgroup species) with focused character sampling (25 loci comprising 35877 bp), along with rigorous alignment, orthology inference and model selection. Key results: Our phylogeny corroborates some earlier inferences and provides novel insights; in particular, we find strong support for Equisetales as sister to the rest of ferns, Marattiales as sister to leptosporangiate ferns, and Dennstaedtiaceae as sister to the eupolypods. Our divergence-time analyses reveal that divergences among the extant fern orders all occurred prior to ∼200 MYA. Finally, our species-tree inferences are congruent with analyses of concatenated data, but generally with lower support. Those cases where species-tree support values are higher than expected involve relationships that have been supported by smaller plastid datasets, suggesting that deep coalescence may be reducing support from the concatenated nuclear data. Conclusions: Our study demonstrates the utility of a curated phylogenomics approach to inferring fern phylogeny, and highlights the need to consider underlying data characteristics, along with data quantity, in phylogenetic studies.
DOI: 10.5683/sp2/whgz1u
title: Data from: The function and evolution of motile DNA replication systems in ciliates

description: AbstractDNA replication is a ubiquitous, complex, and conserved cellular process. However, regulation of DNA replication is only understood in a small fraction of organisms that poorly represent the diversity of genetic systems in nature. Here we used a combination of computational and experimental approaches to examine the function and evolution of one such system, the replication band (RB) in spirotrich ciliates, which is a localized, motile hub that traverses the macronucleus while replicating DNA. We show that the RB can take unique physical forms in different species, ranging from polar bands to a "replication envelope", where replication initiates at the nuclear periphery and advances centripetally inwards. Furthermore, we identified genes involved in cellular transport, including calcium transporters and cytoskeletal regulators, that are associated with the RB and may be involved in its function and translocation. These findings reveal the complex evolution and diversity of motile DNA replication systems and raise new possibilities regarding the regulation of nuclear organization and processes.
DOI: 10.5683/sp2/pqde0o
title: Data from: The genetic architecture of UV floral patterning in sunflower

description: AbstractBackground and Aims: The patterning of floral ultraviolet (UV) pigmentation varies both intra- and interspecifically in sunflowers and many other plant species, impacts pollinator attraction, and can be critical to reproductive success and crop yields. However, the genetic basis for variation in UV patterning is largely unknown. This study examines the genetic architecture for proportional and absolute size of the UV bullseye in Helianthus argophyllus, a close relative of the domesticated sunflower. Methods: A camera modified to capture UV light (320–380 nm) was used to phenotype floral UV patterning in an F2 mapping population, then quantitative trait loci (QTL) were identified using genotyping-by-sequencing and linkage mapping. The ability of these QTL to predict the UV patterning of natural population individuals was also assessed. Key Results: Proportional UV pigmentation is additively controlled by six moderate effect QTL that are predictive of this phenotype in natural populations. In contrast, UV bullseye size is controlled by a single large effect QTL that also controls flowerhead size and co-localizes with a major flowering time QTL in Helianthus. Conclusions: The co-localization of the UV bullseye size QTL, flowerhead size QTL and a previously known flowering time QTL may indicate a single highly pleiotropic locus or several closely linked loci, which could inhibit UV bullseye size from responding to selection without change in correlated characters. The genetic architecture of proportional UV pigmentation is relatively simple and different from that of UV bullseye size, and so should be able to respond to natural or artificial selection independently.
DOI: 10.5683/sp2/eto23u
title: Data from: The genetic basis of speciation in the Giliopsis lineage of Ipomopsis (Polemoniaceae)

description: AbstractOne of the most powerful drivers of speciation in plants is pollinator-mediated disruptive selection, which leads to the divergence of floral traits adapted to the morphology and behavior of different pollinators. Despite the widespread importance of this speciation mechanism, its genetic basis has been explored in only a few groups. Here, we characterize the genetic basis of pollinator-mediated divergence of two species in genus Ipomopsis, I. guttata and I. tenuifolia, using quantitative trait locus (QTL) analyses of floral traits and other variable phenotypes. We detected 1-6 QTLs per trait, with each QTL generally explaining small to modest amounts of the phenotypic variance of a backcross hybrid population. In contrast, flowering time and anthocyanin abundance (a metric of colour variation) were controlled by a few QTLs of relatively large effect. QTLs were strongly clustered within linkage groups, with 26 of 37 QTLs localized to six marker-interval "hotspots," all of which harbored pleiotropic QTLs. In contrast to other studies that have examined the genetic basis of pollinator shifts, our results indicate that, in general, mutations of small to modest effect on phenotype were involved. Thus, the evolutionary transition between the distinct pollination modes of I. guttata and I. tenuifolia likely proceeded incrementally, rather than saltationally.
DOI: 10.5683/sp2/9p2caa
title: Data from: The genetics of adaptation to discrete heterogeneous environments: frequent mutation or large-effect alleles can allow range expansion

description: AbstractRange expansions are complex evolutionary and ecological processes. From an evolutionary standpoint, a populations' adaptive capacity can determine the success or failure of expansion. Using individual-based simulations, we model range expansion over a two-dimensional, approximately continuous landscape. We investigate the ability of populations to adapt across patchy environmental gradients and examine how the effect sizes of mutations influence the ability to adapt to novel environments during range expansion. We find that genetic architecture and landscape patchiness both have the ability to change the outcome of adaptation and expansion over the landscape. Adaptation to new environments succeeds via many mutations of small effect or few of large effect, but not via the intermediate between these cases. Higher genetic variance contributes to increased ability to adapt, but an alternative route of successful adaptation can proceed from low genetic variance scenarios with alleles of sufficiently large effect. Steeper environmental gradients can prevent adaptation and range expansion on both linear and patchy landscapes. When the landscape is partitioned into local patches with sharp changes in phenotypic optimum, the local magnitude of change between subsequent patches in the environment determines the success of adaptation to new patches during expansion.
DOI: 10.5683/sp2/64sita
title: Data from: The importance (or lack thereof) of niche divergence to the maintenance of a northern species complex: the case of the long-toed salamander (Ambystoma macrodactylum Baird)

description: AbstractThe relative importance of ecological versus non-ecological factors for the origin and maintenance of species is an open question in evolutionary biology. Young lineages—such as the distinct genetic groups that make up the ranges of many northern species—represent an opportunity to study the importance of ecological divergence during the early stages of diversification. Yet, few studies have examined the extent of niche divergence between lineages in previously glaciated regions and the role of ecology in maintaining the contact zones between them. In this study, we used tests of niche overlap in combination with ecological niche models to explore the extent of niche divergence between lineages of the long-toed salamander (Ambystoma macrodactylum Baird) species complex and to determine whether contact zones correspond to (divergent) niche limits. We found limited evidence for niche divergence between the different long-toed salamander lineages, substantial overlap in the predicted distribution of suitable climatic space for all lineages and range limits that are independent of niche limits. These results raise questions as to the importance of ecological divergence to the development of this widespread species complex and highlight the potential for non-ecological factors to play a more important role in the maintenance of northern taxa.
DOI: 10.5683/sp2/nogvb1
title: Data from: The magnitude of local adaptation under genotype-dependent dispersal

description: AbstractDispersal moves individuals from patches where their immediate ancestors were successful to sites where their genotypes are untested. As a result, dispersal generally reduces fitness, a phenomenon known as “migration load.” The strength of migration load depends on the pattern of dispersal and can be dramatically lessened or reversed when individuals move preferentially toward patches conferring higher fitness. Evolutionary ecologists have long modeled nonrandom dispersal, focusing primarily on its effects on population density over space, the maintenance of genetic variation, and reproductive isolation. Here, we build upon previous work by calculating how the extent of local adaptation and the migration load are affected when individuals differ in their dispersal rate in a genotype-dependent manner that alters their match to their environment. Examining a one-locus, two-patch model, we show that local adaptation occurs through a combination of natural selection and adaptive dispersal. For a substantial portion of parameter space, adaptive dispersal can be the predominant force generating local adaptation. Furthermore, genetic load may be largely averted with adaptive dispersal whenever individuals move before selective deaths occur. Thus, to understand the mechanisms driving local adaptation, biologists must account for the extent and nature of nonrandom, genotype-dependent dispersal, and the potential for adaptation via spatial sorting of genotypes.
DOI: 10.5683/sp2/tmqf89
title: Data from: The maintenance of obligate sex in finite, structured populations subject to recurrent beneficial and deleterious mutation

description: AbstractAlthough there is no known general explanation as to why sexual populations resist asexual invasion, previous work has shown that sexuals can outcompete asexuals in structured populations. However, it is currently unknown whether costly sex can be maintained with the weak structure that is commonly observed in nature. We investigate the conditions under which obligate sexuals resist asexual invasion in structured populations subject to recurrent mutation. We determine the level of population structure needed to disfavour asexuals, as calculated using the average Fst between all pairs of demes. We show that the critical Fst needed to maintain sex decreases as the population size increases, and approaches modest levels as observed in many natural populations. Sex is maintained with lower Fst if there are both advantageous and deleterious mutation, if mutation rates are sufficiently high, and if deleterious mutants have intermediate selective strengths, which maximises the effect of Muller's Ratchet. Additionally, the critical Fst needed to maintain sex is lower when there are a large number of subpopulations. Lower Fst values are needed to maintain sex when demes vary substantially in their pairwise distances (e.g., when arrayed along one dimension), although this effect is often modest, especially if some long-distance dispersal is present.
DOI: 10.5683/sp2/qlsyya
title: Data from: The molecular phylogeny of Chionaster nivalis reveals a novel order of psychrophilic and globally distributed Tremellomycetes (Fungi, Basidiomycota)

description: AbstractSnow and ice present challenging substrates for cellular growth, yet microbial snow communities not only exist, but are diverse and ecologically impactful. These communities are dominated by green algae, but additional organisms, such as fungi, are also abundant and may be important for nutrient cycling, syntrophic interactions, and community structure in general. However, little is known about these non-algal community members, including their taxonomic affiliations. An example of this is Chionaster nivalis, a unicellular fungus that is morphologically enigmatic and frequently observed in snow communities globally. Despite being described over one hundred years ago, the phylogeny and higher-level taxonomic classifications of C. nivalis remain unknown. Here, we isolated and sequenced the internal transcribed spacer (ITS) and the D1-D2 region of the large subunit ribosomal RNA gene of C. nivalis, providing a molecular barcode for future studies. Phylogenetic analyses using the ITS and D1-D2 region revealed that C. nivalis is part of a novel lineage in the class Tremelomycetes (Basidiomycota, Agaricomycotina) for which a new order, Chionasterales ord. nov. (MB838717), and family, Chionasteraceae fam. nov. (MB838718), are proposed. Comparisons between C. nivalis and sequences generated from environmental surveys revealed that the Chionasterales are globally distributed and probably psychrophilic, as they appear to be limited to the high alpine and arctic regions. These results highlight the unexplored diversity that exists within these extreme habitats and emphasize the utility of single-cell approaches in characterizing these complex algal-dominated communities.
DOI: 10.5683/sp2/1tsnb9
title: Data from: The new Andean jumping spider genus Urupuyu and its placement within a revised classification of the Amycoida (Araneae: Salticidae)

description: AbstractUrupuyu gen. nov. is described for three new species of small black jumping spiders from the cloud forests of Ecuador: Urupuyu antisana sp. nov. (type species), U. edwardsi sp. nov., and U. occidentale sp. nov. Phylogenetic analyses with DNA sequences (28S, actin 5C, wingless, 16SND1 and CO1) indicate Urupuyu is closely related to the huriine amycoids Hurius and Scoturius, a placement also supported by morphological traits. Our phylogenetic analysis serves to clarify the relationships within the Amycoida in general, leading to our proposing a revised classification for the group, with subfamilies Gophoinae, Sitticinae, Bredinae subfam. nov., Scopocirinae, Thiodininae, Sarindinae, Huriinae, Simonellinae, and Amycinae. We confirm the marpissine-like Breda belongs within the Amycoida. The phylogeny implies that ant mimicry has evolved at least twice (simonellines and sarindines) and probably a third time (Atomosphyrus in the thiodinines) within the Amycoida. The following new synonymies are proposed for suprageneric names: Hyetusseae Simon, 1903 and Arachnomureae Mello-Leitão, 1917 = Thiodininae Simon, 1901; Zunigeae Simon, 1901 = Sarindinae Simon, 1901; Synemosynae Banks, 1892 = Simonellinae Peckham, Peckham & Wheeler, 1888; Magoninae Petrunkevitch, 1928 = Amycinae F.O.P.-Cambridge, 1900.
DOI: 10.5683/sp2/iaafsy
title: Data from: The origin and evolution of phototropins

description: AbstractPlant phototropism, the ability to bend toward or away from light, is predominantly controlled by blue-light photoreceptors, the phototropins. Although phototropins have been well-characterized in Arabidopsis thaliana, their evolutionary history is largely unknown. In this study, we complete an in-depth survey of phototropin homologs across land plants and algae using newly available transcriptomic and genomic data. We show that phototropins originated in an ancestor of Viridiplantae (land plants + green algae). Phototropins repeatedly underwent independent duplications in most major land-plant lineages (mosses, lycophytes, ferns, and seed plants), but remained single-copy genes in liverworts and hornworts—an evolutionary pattern shared with another family of photoreceptors, the phytochromes. Following each major duplication event, the phototropins differentiated in parallel, resulting in two specialized, yet partially overlapping, functional forms that primarily mediate either low- or high-light responses. Our detailed phylogeny enables us to not only uncover new phototropin lineages, but also link our understanding of phototropin function in Arabidopsis with what is known in Adiantum and Physcomitrella (the major model organisms outside of flowering plants). We propose that the convergent functional divergences of phototropin paralogs likely contributed to the success of plants through time in adapting to habitats with diverse and heterogeneous light conditions.