ARTICLE | doi:10.20944/preprints201907.0153.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: fungal endophytes; fungal dispersal; fungal culturing
Online: 11 July 2019 (07:40:35 CEST)
Fungal endophytes have been found in all plants surveyed to date, yet for many fungi the function of endophytism is still unknown. The Foraging Ascomycete Hypothesis (FAH) proposes that saprotrophic fungi utilize an endophytic stage in leaves to modify dispersal. Under this hypothesis, leaves can provide food and water during time of environmental scarcity and they can transport the fungi to other substrates upon dehiscence. If the FAH is accurate, then some endophytes should have the ability to colonize saprobic substrates directly from a leaf-endophyte stage, though this has been little studied. To assess this ability, twelve surface-sterilized leaves of a tropical tree (Nectandra lineatifolia Mez) were placed directly on wood and incubated for six weeks. Fungi from the wood were subsequently cultured and identified by ITS sequences or morphology. 477 fungal isolates comprising 26 OTUs were cultured from the wood, the majority of which belong to saprotrophic genera (70.8% of OTUs, 82.3% of isolates). The mean OTU richness per leaf was 5.67. The term viaphyte (literally, “by way of plant”) is introduced and defined as fungi that colonize living leaves as endophytes and use the leaves to transfer to another substrate, such as wood, when the leaves dehisce. These results strengthen the Foraging Ascomycete Hypothesis and expose the possibility that viaphytism plays a significant role in the dispersal of fungal saprotrophs.
ARTICLE | doi:10.20944/preprints202303.0396.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Computation; Cost Allocation; Dispersal; Game Theory; Landscape
Online: 22 March 2023 (10:29:28 CET)
Species dispersal from a territorial zone is a complex process. The reasons for species dispersal are determined by both natural and human factors. The purpose of this study is to develop a cost surface for a hypothetical landscape that accounts for various species dispersion features. With tigers (Panthera Tigris Tigris) as the focal species, a model for a hypothetical landscape has been built to predict the dispersion patterns of the species' individuals from one habitat patch to another. Initially, four major factors influencing tiger dispersal are explored. Following that, Game Theory assigns a score to each grid in the landscape matrix based on the landscape features in the focal landscape. Specific predefined ratings are also utilized for scenarios that are very complex and may change depending on variables, such as the interaction of the dispersing tiger with co-predators. The two scores mentioned above are combined to create a cost matrix that is shown across a landscape complex to estimate the impact of each landscape component on tiger dispersal. This approach helps wildlife managers develop conservation plans by recognizing important characteristics in the landscape. The results of the model like the one described in this work might be beneficial for a wide range of wildlife management activities such as corridor management, smart patrols, and so on. A cost surface over any focal landscape may serve as a basis for policy and purpose design based on current landscape conditions.
REVIEW | doi:10.20944/preprints202212.0360.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Dispersal range; nesting habitat; reproduction; caste system; ecological dominance
Online: 20 December 2022 (08:40:04 CET)
This review discusses the distribution pattern, nesting style, mating behavior, and colony structure of the Asian weaver ants (Oecophylla smaragdina) in Asia. Recent findings suggested that weaver ant occurrences are not only limited to tropical rainforests biome, agroforestry and large monoculture fields, but have encroached human rural habitation including densely populated urban areas. Comparatively, O. longinoda and O. smaragdina are taxonomically classified as two distinct species, but the main differences between them are strongly dependent on the allopatric nature or geographical speciation of their distribution. Although weaver ants are dominant ubiquitous and conspicuous arboreal insects with a predilection for habitation in trees canopies, viable nests colonies on the ground have been reported in Thailand. O. smaragdina usually construct their polydomous nests (multiple satellites nests arrangement within a single host but diverse plants species) by weaving tree-leaves using their larval silk. Knowledge on mating behavior is rudimentary; hence more studies are needed especially in understanding how weather parameters affect nuptial flight swarming act. At the colony organization level, comprehensive reports about minor and major workers contrasts with the poorly documented but significant intermediate size of workers caste. The versatile impact of Asian Oecophylla is offering important ecological subsistence services to both the nature and humans. This is by combining positive economic implications to food security concern with a provision of organic nutrients for host plants and highly healthful diet enhancer (nourishing-medicinal). Despite its wide presence in large oil palms monoculture, only one report had exposed weaver ants’ potential positive ecological impact (i.e. predation on bagworms Pteroma pendula) in Southeast Asia.
REVIEW | doi:10.20944/preprints202111.0463.v2
Subject: Environmental And Earth Sciences, Paleontology Keywords: taxonomy; biogeography; evolution; domestication; dispersal; pollen; archaeology; hemp; drugs
Online: 2 December 2021 (08:55:17 CET)
Cannabis is among the oldest human domesticates and has been subjected to intensive artificial (human-mediated) selection throughout history to create a wide array of varieties and biotypes for diverse uses, including fibre, food, biofuel, medicine and drugs. This paper briefly reviews the available literature on the taxonomy, evolutionary origin and domestication of this plant, as well as its worldwide dispersal, in both its wild and cultivated forms. Emphasis is placed on Europe and especially on the Iberian Peninsula. Today, it is accepted that Cannabis is a monospecific genus with two subspecies, C. sativa subsp. sativa and C. sativa subsp. indica, originating in Europe and Asia, respectively, by allopatric differentiation after geographic isolation fostered by Pleistocene glacial-interglacial cycles. Palynological and phylogeographic evidence situates the Cannabis ancestor on the NE Tibetan Plateau during the mid-Oligocene. The timing and place of domestication is still a matter of debate between contrasting views that defend single or multiple Neolithic domestication centres situated in different parts of the Eurasian supercontinent, notably central/southeastern China and the Caucasus region. Recent meta-analyses have suggested that wild Cannabis may have already been spread across Europe in the Pleistocene, and its domestication could have occurred during the European Copper/Bronze ages. According to the available reviews and meta-analyses, pre-anthropic dispersal of Cannabis into the Iberian Peninsula seems to have occurred only in postglacial times, and the earlier signs of cultivation date to the Early Medieval Ages. However, the palynological and archaeological evidence used to date is insufficient for a sound assessment, and the development of thorough Iberian databases to address further meta-analysis is essential for more robust conclusions. Some clues are provided for these achievements to be fulfilled.
REVIEW | doi:10.20944/preprints201806.0162.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: abscission layer; artificial selection; crop domestication; dehiscence; legumes; seed dispersal
Online: 11 June 2018 (15:28:54 CEST)
In wild habitats, fruit dehiscence is a critical strategy for seed dispersal; however, in cultivated crops it is one of the major sources of yield loss. Therefore, indehiscence of fruits, pods, etc., was likely to be one of the first traits strongly selected in crop domestication. Even with the historical selection against dehiscence in early domesticates, it is a trait still targeted in many breeding programs, particularly in minor or underutilized crops. Here, we review of this trait in pulse (grain legume) crops, which are of growing importance as a source of protein in human and livestock diets, and which have received less attention than cereal crops and the model plant Arabidopsis thaliana. We specifically focus on the i) history of indehiscence in domestication across legumes, ii) structures and the mechanisms involved in shattering, iii) the molecular pathways underlying this important trait, iv) an overview of the extent of crop losses due to shattering, and the effects of environmental factors on shattering, and, v) efforts to reduce shattering in crops. While our focus is mainly pulse crops, we also included comparisons to crucifers and cereals because there is extensive research on shattering in these taxa.
ARTICLE | doi:10.20944/preprints202306.0526.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Dispersal; Connectivity; Movement; Conservation Genomics; Madagascar; Habitat Loss and Fragmentation; Rodents
Online: 7 June 2023 (09:30:53 CEST)
Habitat loss and fragmentation are of concern to conservation biologists worldwide. However, not all organisms are affected equally by these processes, thus it is important to study the effects of living in fragmented habitats on species that differ in lifestyle and habitat requirements. In this study we examined dispersal and connectivity patterns of rodents, one endemic (Eliurus myoxinus) and one invasive (Rattus rattus), in two landscapes containing forest fragments and adjacent continuous forest patches in northwestern Madagascar. We generated genomic (RADseq) data for 66 E. myoxinus and 81 R. rattus individuals to evaluate differences in genetic diversity as well as inbreeding and connectivity in two landscapes. We found higher levels of inbreeding and lower levels of genetic diversity in E. myoxinus compared with R. rattus. We observed related dyads both within and between habitat patches and positive spatial autocorrelation at lower distance classes for both species, with a stronger pattern of spatial autocorrelation in R. rattus. Across each site we identified contrasting migration rates for each species, but these did not correspond to habitat-matrix dichotomies. The relatively low genetic diversity in the endemic E. myoxinus suggests ecological constraints that require further investigation.
ARTICLE | doi:10.20944/preprints201809.0096.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Montiaceae; phylogeny; phylogeography; long-distance dispersal; idiosyncrasy; Principal of Evolutionary Idiosyncraticity
Online: 5 September 2018 (12:02:42 CEST)
Montiaceae comprise a clade of at least 270 species plus about 20 accepted subspecific taxa, primarily of western America and Australia. The present paper is the first of a two-part work that seeks to evaluate evolutionary theory via metadata analysis of Montiaceae. In particular, it uses metadata analysis to evaluate the theory in theory-laden methods that have been applied in evolutionary analyses of Montiaceae. This part focuses on phylogeny and phylogeography. The second part focuses on phenotypic and ecological diversification. An emergent theme in this paper is the degree to which historical idiosyncrasy during Montiaceae evolution misleads quantitative methods of evolutionary reconstruction and phylogeographic interpretation. This suggests that idiosyncraticity itself is a fundamental property of evolution. The second part of this work elaborates this notion as the Principle of Evolutionary Idiosyncraticity. The present part describes idiosyncraticity in molecular phylogenetic and phylogeographic data and uses this notion to refine ideas on Montiaceae evolution. Phylogenetic metadata conflicts and conflicting phylogeographic interpretations are discussed. I conclude that, owing to PEI, quantitative methods of evolutionary analysis cannot be globally accurate, though they are useful heuristically. In contrast, classical narrative analysis is robust in the face of PEI.
ARTICLE | doi:10.20944/preprints201809.0168.v1
Subject: Environmental And Earth Sciences, Geography Keywords: avulsion, civil defence, dispersal barrier, flood, Rio Madeira, rain forest, species distribution
Online: 10 September 2018 (11:59:52 CEST)
The scene for regional biogeography and human settlements in Central Amazonia is set by the river network, which presumably consolidated in the Pliocene. However, we present geomorphological and sediment chronological data showing that the river network has been anything but stable. Even during the last 50 kyr, the tributary relationships have repeatedly changed for four major rivers, together corresponding to one third of the discharge of the Amazon. The latest major river capture event converted the Japurá from a tributary of the Rio Negro to a tributary of the Amazon only 1000 years ago. Such broad-scale lability implies that rivers cannot have been as efficient biogeographical dispersal barriers as has generally been assumed, but that their effects on human societies can have been even more profound. Climate change and deforestation scenarios predict increasing water levels during peak floods, which will likely increase the risk of future river avulsions. This may have disastrous consequences for the local human societies, especially in those areas where the current floodplains are at only marginally lower elevations than the nearest water divide. We suggest that the prevailing paradigm of rivers as principal structuring elements of Amazonian biogeography needs to be re-evaluated, and that land use planning and civil risk assessment should take the possibility of river avulsions into account.
ARTICLE | doi:10.20944/preprints202206.0262.v2
Subject: Physical Sciences, Fluids And Plasmas Physics Keywords: Dandelion; pappus; flexible filament; wind-dispersal; aerodynamic shape; drag; Reynolds number; scaling laws
Online: 12 April 2023 (04:46:14 CEST)
The common dandelion uses a bundle of drag-enhancing bristles (the pappus) that enables seed dispersal over formidable distances; however, the scaling laws of aerodynamic drag underpinning pappus-mediated flight remains unresolved. In this paper, we study the aerodynamic shape of dandelion, derive the scaling law of resistance, determine the Vogel exponent. In particular, we find that the total drag coefficient is proportional to the -2/3 power of the dandelion pappus Reynolds number, and obtain the terminal velocity of the dandelion seed under gravitation field.
ARTICLE | doi:10.20944/preprints202007.0577.v1
Subject: Public Health And Healthcare, Public, Environmental And Occupational Health Keywords: COVID-19; Coronavirus; SARS-CoV2; Random walks; Population dispersal; Diffusion; Lockdown; Confinement; Movement restrictions; Disease spread; Kuwait
Online: 24 July 2020 (10:57:04 CEST)
To mitigate the spread of the COVID-19 coronavirus, some countries have enforced more stringent non-pharmaceutical interventions in contrast to those widely adopted (for e.g. the state of Kuwait). In addition to standard practices such as enforcing curfews, social distancing, and closure of non-essential service industries, other non-conventional policies such as the total confinement of highly populated areas has also been implemented. In this paper, we model the movement of a host population using a mechanistic approach based on random walks, which are either diffusive or super-diffusive. Infections are realised through a contact process, whereby a susceptible host may be infected if in close spatial proximity of the infectious host. Our focus is only on the short-time scale prior to the infectious period, so that no further transmission is assumed. We find that the level of infection depends heavily on the population dynamics, and increases in the case of slow population diffusion, but remains stable for a high or super-diffusive population. Also, we find that the confinement of homogeneous or overcrowded sub-populations has minimal impact in the short term. Finally, we discuss the possible implications of our findings for total confinement in the context of the current situation in Kuwait.
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: non-native populations; geographic expansion; invasiveness; invasibility; dispersal; phenotypic plasticity; evolution; historical ecosystem; hybrid ecosystem; novel ecosystem
Online: 30 October 2019 (07:13:34 CET)
Biological invasions have reached an unprecedented level and the number of introduced species is still increasing worldwide. Despite major advances in invasion science, the determinants of success of introduced species, the magnitude and dimensions of their impact, and the mechanisms sustaining successful invasions are still debated. Empirical studies show divergent impacts of non-native populations on ecosystems and contrasting effects of biotic and abiotic factors on the dynamics of non-native populations; this is hindering the emergence of a unified theory of biological invasions. We propose a synthesis that merges perspectives from population, community, and ecosystem levels. Along a timeline of ecosystem transformation driven by non-native species, from historical to human-modified ecosystems, we order invasion concepts and theories to clarify their chaining and relevance during each step of the invasion process. This temporal sorting of invasion concepts shows that each concept is relevant at a specific stage of the invasion. Concepts and empirical findings on non-native species may appear contradictory. However, we suggest that, when mapped onto an invasion timeline, they may be combined in a complementary way. An overall scheme is proposed to summarise the theoretical dynamics of ecosystems subjected to invasions. For any given case study, this framework provides a guide through the maze of theories and should help choose the appropriate concepts according to the stage of invasion.
Subject: Biology And Life Sciences, Virology Keywords: SARS-CoV-2; COVID-19; novel severe acute respiratory syndrome coronavirus 2; ancestral reconstruction; clonality; source of entry; dispersal routes
Online: 28 June 2020 (09:21:49 CEST)
The coronavirus disease 2019 (COVID-19) was officially declared a pandemic on the 11th March 2020. It is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), impacting the lower respiratory tract. International travel to Australia during the early stages of the pandemic prior to border closure provided avenues for this virus to spread into Australia. There is little understanding of the clonality of SARS-CoV-2 isolates in Australia, and where they originated. This study aimed to investigate the clonality and ancestral sources of SARS-CoV-2 isolates in Australia using in silico methods. We retrieved 1,346 complete genomes from Australia along with 153 genomes from other countries from the NCBI nucleotide database and Global Initiative On Sharing All Influenza Data (GISAID). We then constructed a representative population of 270 sequences for downstream phylogenetic analysis and ancestral area reconstruction. Overall, two major clusters, one stemming from Europe and another from Asia, especially East Asia, were observed, implying at least two major transmission events with subsequent clades confirming the multiclonality of Australian isolates. We also identified three potential dissemination routes of SARS-CoV-2 into Australia. This study supports the hypothesis of multiple clonality and dispersals of SARS-CoV-2 isolates into Australia.