First record, taxonomy and temporal/spatial dispersion pattern of species in genus Pontella (Crustacea:Copepoda:Calanoida) from coastal/estuarine waters of Bushehr

The vertical distribution of crustacean zooplankton species was examined during 2000 in Windermere, Cumbria. Patterns of dispersion were evaluated quantitatively using two different approaches. Firstly, Morisita’s index was used to test whether patterns of dispersion differed significantly from a state of randomness and, secondly, the relative distribution of zooplankton individuals between the epilimnion and hypolimnion was investigated, for a series of standardised vertical profiles of organism density. All six of the dominant species of planktonic crustaceans showed aggregated patterns of dispersion throughout the year. For most species, patterns of dispersion were affected by the onset and breakdown of thermal stratification in the lake. The degree of aggregation in the vertical plane, measured using Morisita’s index, increased when the lake became thermally stratified. Furthermore, for most species, there was a positive association between the degree of vertical differentiation in abundance across the thermocline, and the degree of temperature differentiation in the stratified water column. The results of the present analysis provide quantitative evidence for the phenomenon known as ‘zooplankton stratification’ and for temporal variation in patterns of zooplankton dispersion.

Substratum effects on cell dispersal, morphology, and differentiation in cultures of avian neural crest cells

Spatial and temporal effects of terebellid polychaete tubes on soft-bottom community structure in Phosphorescent Bay, Puerto Rico

Many bivalves have an unusual mechanism of mitochondrial DNA (mtDNA) inheritance called doubly uniparental inheritance (DUI) in which distinctly different genomes are inherited through the female (F genome) and male (M genome) lineages. In fertilized eggs that will develop into male embryos, the sperm mitochondria remain in an aggregation, which is believed to be delivered to the primordial germ cells and passed to the next generation through the sperm. In fertilized eggs that will develop into female embryos, the sperm mitochondria are dispersed throughout the developing embryo and make little if any contribution to the next generation. The frequency of embryos with the aggregated or dispersed mitochondrial type varies among females. Previous models of DUI have predicted that maternal nuclear factors cause molecular differences among unfertilized eggs from females producing embryos with predominantly dispersed or aggregated mitochondria. We test this hypothesis using females of each of the two types from a natural population. We have found small, yet detectable, differences of the predicted type at the proteome level. We also provide evidence that eggs of females giving the dispersed pattern have consistently lower expression for different proteasome subunits than eggs of females giving the aggregated pattern. These results, combined with those of an earlier study in which we used hatchery lines of Mytilus, and with a transcriptomic study in a clam that has the DUI system of mtDNA transmission, reinforce the hypothesis that the ubiquitin-proteasome system plays a key role in the mechanism of DUI and sex determination in bivalves. We also report that eggs of females giving the dispersed pattern have higher expression for arginine kinase and enolase, enzymes involved in energy production, whereas ferritin, which is involved in iron homeostasis, has lower expression. We discuss these results in the context of genetic models for DUI and suggest experimental methods for further understanding the role of these proteins in DUI.

In northern Manitoba, carbonates were glacially dispersed westwards for distances up to 260 km beyond the limit of carbonate bedrock. The dispersal pattern in the surface till reflects the interaction of Keewatin and Hudson – Labrador ice in the region during the Wisconsin glaciation and suggests the presence of ice streams within the Laurentide Ice Sheet. Pre-Wisconsinan tills show different dispersal and ice-flow patterns. In unfrozen terrain, carbonate till sheets on the Shield buffer the effects of natural lake acidification and acid rain; however, their ability to buffer appears to be severely limited in permafrost terrain.

Simple SummarySemiaquatic bugs have colonized the water surface of most aquatic habitats, from small and temporary puddles and streams to the open ocean. Most semiaquatic bugs are wing-polymorphic, as some individuals have fully developed wings (macropterous) and others have shortened wings (brachypterous) or are wingless (apterous). This is characteristic for most temperate water striders, common on lakes, fishponds, and pools around the world. The report presented here is based on the collection of more than 23,000 individuals of nine species of semiaquatic bugs that were individually marked by a unique code and released. The recaptures revealed several distinct dispersal strategies, with differences among individual species. Collection of the marked bugs also helped to describe dispersal via the water surface by flightless individuals. Using the results of the presented survey, our knowledge of these interesting insects is considerably extended, and it can help us to understand the general dispersal patterns of aquatic insects.Semiaquatic bugs (Hemiptera: Heteroptera: Gerromorpha) are mostly wing-polymorphic species with flight dispersal as an important life history trait, but the specific flight ability and dispersal pattern remain unexplored in most species. This report presents the results of a long-term survey based on the individual marking of more than 23,000 specimens of eight water striders (Gerridae) and a water cricket Velia caprai (Veliidae). Three distinct lentic habitats were sampled (solitary fishponds, systems of nearby fishponds and systems of small, often temporary pools) and one lotic habitat—a small forest stream. Recaptures revealed that three gerrid species tend to stay at the breeding site, but can differ in dispersal via the water surface. Reproductive flightless females disperse most actively via the water surface, possibly bypassing the trade-off between dispersal and reproduction. One species has a sex-dependent dispersal pattern, with females being rather philopatric, whereas males often disperse. Three other gerrid species are highly dispersive and tend to change breeding site. V. caprai, the only lotic species included in this survey, tend to move upstream and possibly compensate for the downstream drift.

We examined whether δ 15 N levels of marine biota with different nutrient uptake character- istics can be used to trace the dispersal of sewage effluent in highly mixed, nitrogen-limited waters, and whether they can reveal the dispersal of sewage over different timescales. We hypothesised that macro- algal species with fast uptake rates would display a spatial pattern in δ 15 N levels reflecting recent sewage dispersal while those with slower rates would provide a signal integrated over a longer time period. Filter- feeding sponges and ascidians were also sampled to see if they reflected patterns in the dispersal of sewage particulate organic matter (POM). A laboratory experiment was performed to test whether the δ 15 N level of 3 macroalgal species (Ulva australis, Vidalia sp. and Ecklonia radiata) and 2 filter-feeding species (Clathria sp. and Pyura australis) was altered after cultivation in sewage nitrogen. We then sampled each organism along transects radiating away from the outlet of a wastewater treatment plant north of Perth, Western Australia, to determine spatial patterns in δ 15 N. U. australis and Vidalia sp. developed higher iso- topic signatures when exposed to low concentrations of sewage nitrogen (1:500 dilution in seawater) for 7 d in the laboratory. U. australis and Vidalia sp. showed an increase of 1.7 and 1.4‰ in treatments respectively. In the field, macroalgae sampled north and south of the sewage outlet generally had higher δ 15 N levels than those sampled west of the outlet and at the reference site, and algae within 500 m of the outfall tended to have lower values than at 1000 m or more from the outfall. These trends are consistent with our current knowledge of plume dynamics: a predominantly northerly drift of effluent as a buoyant plume that tends not to be fully mixed in the water column for the first 500 m. The results confirmed that the δ 15 N signature of macroalgae could be used to trace sewage disposed in well-mixed waters. The strength of the spatial trends varied between algae, with E. radiata, the species with the lowest nutrient uptake rates and affin- ity, having the least spatial variability. We interpret this as reflecting a wider regional dispersal of sewage in the longer time frame, but a strong northerly drift in the short term, which was reflected in the δ 15 N values of the species with the fastest nitrogen uptake rates. The results were consistent with our hypothesis and are suggestive of a relationship between algal functional form and isotopic signatures that can be applied to determine the dispersal of sewage over different timescales. The δ 15 N values of benthic filter feeders did not provide strong evidence to suggest that they can be used to represent the dispersal of sewage POM, but trends found in the field experiment for Clathria sp. warrant further investigation.

Patterns of gene dispersal by seeds and pollen greatly influence the genetic structure of plant populations and their effective size. This paper reviews methods of measuring gene dispersal and current information on patterns of dispersal within local populations of forest trees. Recently, a number of statistical procedures for investigating gene movement based on the use of large numbers of isozyme loci have been described. These procedures include various forms of parentage analysis and the fitting of mating models to genotypic arrays of offspring from individual maternal plants. With the levels of genetic discrimination currently possible in forest trees, the model approach appears to be the most reliable means of estimating gene dispersal parameters. Too little data are available to draw general conclusions about patterns of gene movement within natural populations. Nevertheless, reports to date indicate that dispersal by both pollen and seed can be considerable. For any one mother tree, the bulk of effective pollen in conifers may come from distant males in the same stand or from surrounding stands (gene flow). In insectpollinated angiosperms, gene flow may also be substantial, but cross—fertilization within stands may primarily be between nearest flowering trees.

After the domestication of plants and animals, the subsequent spread of agriculture represented a process of adaptation of both species and landscapes. Crop species moved beyond their original ecological limits, and their range expansion, when successful, was generally the result of adaptive post-domestication genetic changes on the part of the plants, human-induced changes in agricultural landscapes, and the dynamics of cultural food choice. This chapter explores the patterns by which agriculture became established as a consequence of the diffusion of domesticated plants (and sometimes people), as well as the ways in which agricultural systems were gradually transformed through the diversification of crop packages. Comparisons from across Eurasia are drawn to identify general patterns in crop dispersal, with three categories playing the largest role in the diffusion of grain-based agriculture. These agricultural systems are discussed and their modes of diffusion, stories of collapse, and examples of new adaptations on the part of the crops and agricultural systems detailed. Keywords : Agriculture, Neolithic, domestication, cuisine, archaeobotany INTRODUCTION Agriculture is widely regarded as one of the key changes in ecological and economic systems in the history of Homo sapiens (Diamond 2002; Bellwood 2005; Barker 2006; Smith and Zeder 2013). There is no doubt that agriculture set in motion increases in human population density and the transformation of environments, from biomes to ‘anthromes’ (sensu Ellis 2011). Over the long-term, land-use intensified primarily through agriculture, supporting denser populations and increasing regional carrying capacity by supporting more people from less land (Ellis et al. 2013). In this regard there should be little surprise that anthropologists and archaeologists have expended considerable effort on the study of agricultural origins, although more often than not this has focused on the search for pristine origins – those relatively few instances in which hunter-gatherers became farmers by domesticating plants and animals that were wild in their environment. As archaeological research and biological studies of wild progenitors have progressed, the number of recognized centres of origins has expanded from half a dozen or less, to close to ten, and perhaps even twenty or more (Fuller 2010; Larson et al. 2014). Nevertheless, it is undeniable that for the majority of the planet, agriculture was introduced from elsewhere and was based on plants and animals introduced as domesticates.

Social inequality, disadvantaged neighbourhoods and transport deprivation: an assessment of the historical influence of housing policies

Gibbons of both sexes have been observed emigrating from their natal groups, but the consequences of dispersal in gibbons are poorly understood, and it is unclear whether these are the same for both sexes. I sequenced a 350-bp fragment of mitochondrial DNA from 18 adults in seven siamang (Symphalangus syndactylus) groups at the Way Canguk Research Station in southern Sumatra to assess patterns of matrilineal relatedness among and within siamang groups, and to assess their fit with different patterns of sex-specific dispersal. A total of 11 haplotypes were identified in the seven study groups; 50% of adult males in five contiguous groups shared a haplotype with a member of an immediately adjacent group, whereas only 16.7% of females shared a haplotype with a neighbor. The apparent difference persisted if only same-sex individuals were considered (37.5% of males vs. 0% of females). Four of the seven study groups contained two adult males and a single adult female. In three multimale groups, the three adults all had different haplotypes, suggesting that neither male was the retained adult offspring of the female, whereas in the fourth group, the haplotype of one male was identical with that of the adult female. The high diversity of haplotypes and the absence of clustering among female haplotypes in the study neighborhood suggest that female dispersal to territories adjacent to the natal group may be relatively rare. The presence of some clustering of male haplotypes suggests that shorter dispersal distances may be more common in males.

The late-stage larvae of many reef fishes possess strong swimming abilities that may allow them to influence their dispersal. However, due to the challenges associated with directly measuring patterns of larval dispersal, determining how swimming abilities relate to dispersal outcomes remains a critical gap in our knowledge of the mechanisms that shape dispersal patterns. In this study, we first investigated the ontogeny of swimming speed and endurance in lab-reared larvae of the clown anemonefish (Amphiprion percula), and neon gobies (Elacatinus lori and E. colini). In general, the swimming speed and endurance of larvae improved with age. The congeners, E. lori and E. colini, possessed similar swimming speed and endurance, while A. percula was capable of swimming nearly twice as fast and 322 times longer than either Elacatinus. Second, to relate swimming abilities and other larval traits with patterns of dispersal, we searched the literature for all species in which the dispersal kernel, swimming speed, larval body size and pelagic larval duration have been measured. We found complete datasets for three species: A. percula, E. lori and Plectropomus leopardus. For these species, maximum swimming speed was a better predictor of long-distance dispersal than other larval traits. Thus, we propose the testable hypothesis that swimming abilities may play an important role in determining the extent of long-distance dispersal. Testing this hypothesis, and the alternatives, will require measuring the dispersal kernel, swimming speed, and other dispersal-related larval traits of multiple species in the same seascape.

In studying populations of the land snailArianta arbustorumin the eastern Swiss Alps, juvenile and subadult snails were found to be aggregated all the time, while adults were mostly aggregated during summer, the main mating period. The mean size of aggregations was 25 cm × 25 cm but varied, according to the area a grass tuft covered, while the intensity of aggregations was influenced by weather conditions. Densities of 10–15 subadults and 3–6 adults m−2were found along ditches and streams, 2–25 subadults and 2–20 adults on uncultivated alpine meadows, while on scree‐covered alpine grassland the density of subadults and adults was 0.3–0.5 m−2. The extent of daily movements varied with microclimatic factors and season and depended on the structure of the habitat. The dispersal rate was greatest in June (2.6 m month−1) and least in August (1.1 m month−1). In summer and autumn, active uphill movements were noted, a process which compensates for the loss of altitude by passive downhill displacements. Roiling down on snowfields and being carried away by avalanches and streams were observed.

This chapter presents some background considerations relevant to the patterns of language dispersal and diversification in Island Southeast Asia and Oceania. First an overview of languages and language families is given, including three large families—the widely dispersed Austronesian family, the Trans New Guinea (TNG) family in New Guinea, and the Pama-Nyungan family in Australia—as well as many smaller families and isolates. Then the main distinctive typological features of Austronesian languages, New Guinea and Australia are presented. Australia shows surprising structural homogeneity when compared to New Guinea and even to Austronesian. Subsequent sections cover the history of the study of the languages in the region, the history of the region itself, and issues for further research, including the mechanisms in the spread of Austronesian and the language development of New Guinea. The chapter concludes with a brief summary of the chapters in the book regarding the region.

To correlate clonal patterns in the rat striatum with adult neuronal phenotypes, we labeled striatal progenitors between embryonic day 14 (E14) and E19 with a retroviral library encoding alkaline phosphatase. In the adult striatum, the majority of E14-labeled neurons (87%) were members of discrete horizontal or radial cell clusters. Radial clusters accounted for only 23% of cell clusters but >34% of labeled cells. Striatal clones also demonstrated an unexpected widespread pattern of clonal dispersion. The majority of striatal clones were widely dispersed within the striatum, and 80% of clones were part of even larger clones that included cortical interneurons. Finally, we observed that PCR-positive cortical interneurons were members of clones containing both interneurons and pyramids (44%), exclusively interneuron clones (24%), or combined striatal-cortical clones (16%), consistent with the view that cortical interneurons have multiple origins in differentially behaving progenitor cells. Our data are also consistent with the notion that similar mechanisms underpin striatal and cortical development.