Unravelling evolutionary lineages among South African velvet worms (Onychophora: Peripatopsis) provides evidence for widespread cryptic speciation

The endemic South African velvet worm genus Peripatopsis currently contains eight recognized species described from variable morphological characters and the current taxonomy is unsatisfactory. In an attempt to investigate evolutionary relationships within Peripatopsis, we collected 137 individuals from 34 sample localities for six of the eight species. Sequence data derived from two partial mitochondrial (mt)DNA gene loci (COI and 12S rRNA), as well as partial sequence data from the ribosomal nuclear 18S rDNA locus in combination with gross morphological characters and scanning electron microscopy (SEM), was used to examine evolutionary relationships. Phylogenetic relationships were investigated using minimum evolution (ME) and Bayesian inferences (BI). Additionally, we also undertook a maximum likelihood (ML) analyses on the combined DNA sequence data set. The combined DNA evidence topologies derived from the ME, BI, and ML was highly congruent and was characterized by the presence of multiple lineages within recognized taxa. Peripatopsis clavigera, Peripatopsis moseleyi, and Peripatopsis sedgwicki each comprised two evolutionary lineages; Peripatopsis capensis comprised three; and Peripatopsis balfouri comprised six operational taxonomic units respectively. Genealogical exclusivity at both mtDNA and nuclear DNA among the geographically coherent groups coupled with pronounced sequence divergence suggested a two‐fold increase in the number of species within Peripatopsis. Previously used gross morphological characters (such as the number of leg pairs and colour) were either highly variable within operational taxonomic units, or were invariant, suggesting that alternative morphological characters are necessary for species discrimination. SEM results revealed potentially useful diagnostic characters that can discriminate between at least discriminate some of the newly‐identified lineages. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society 2009, 97 , 200–216.     

Phylogeography of lions (Panthera leo ssp.) reveals three distinct taxa and a late Pleistocene reduction in genetic diversity

Lions were the most widespread carnivores in the late Pleistocene, ranging from southern Africa to the southern USA, but little is known about the evolutionary relationships among these Pleistocene populations or the dynamics that led to their extinction. Using ancient DNA techniques, we obtained mitochondrial sequences from 52 individuals sampled across the present and former range of lions. Phylogenetic analysis revealed three distinct clusters: (i) modern lions, Panthera leo ; (ii) extinct Pleistocene cave lions, which formed a homogeneous population extending from Europe across Beringia (Siberia, Alaska and western Canada); and (iii) extinct American lions, which formed a separate population south of the Pleistocene ice sheets. The American lion appears to have become genetically isolated around 340 000 years ago, despite the apparent lack of significant barriers to gene flow with Beringian populations through much of the late Pleistocene. We found potential evidence of a severe population bottleneck in the cave lion during the previous interstadial, sometime after 48 000 years, adding to evidence from bison, mammoths, horses and brown bears that megafaunal populations underwent major genetic alterations throughout the last interstadial, potentially presaging the processes involved in the subsequent end-Pleistocene mass extinctions.     

Disturbance, rainfall and contrasting species responses mediated aboveground biomass response to 11 years of CO2 enrichment in a Florida scrub-oak ecosystem

This study reports the aboveground biomass response of a fire-regenerated Florida scrub-oak ecosystem exposed to elevated CO₂ (1996–2007), from emergence after fire through canopy closure. Eleven years exposure to elevated CO₂ caused a 67% increase in aboveground shoot biomass. Growth stimulation was sustained throughout the experiment; although there was significant variability between years. The absolute stimulation of aboveground biomass generally declined over time, reflecting increasing environmental limitations to long-term growth response. Extensive defoliation caused by hurricanes in September 2004 was followed by a strong increase in shoot density in 2005 that may have resulted from reopening the canopy and relocating nitrogen from leaves to the nutrient-poor soil. Biomass response to elevated CO₂ was driven primarily by stimulation of growth of the dominant species, Quercus myrtifolia , while Quercus geminata , the other co-dominant oak, displayed no significant CO₂ response. Aboveground growth also displayed interannual variation, which was correlated with total annual rainfall. The rainfall × CO₂ interaction was partially masked at the community level by species-specific responses: elevated CO₂ had an ameliorating effect on Q. myrtifolia growth under water stress. The results of this long-term study not only show that atmospheric CO₂ concentration had a consistent stimulating effect on aboveground biomass production, but also showed that available water is the primary driver of interannual variation in shoot growth and that the long-term response to elevated CO₂ may have been caused by other factors such as nutrient limitation and disturbance.     

The determination of activity of the enzyme Rubisco in cell extracts of the dinoflagellate alga Symbiodinium sp. by manganese chemiluminescence and its response to short‐term thermal stress of the alga

The dinoflagellate alga Symbiodinium sp., living in symbiosis with corals, clams and other invertebrates, is a primary producer in coral reefs and other marine ecosystems. The function of the carbon‐fixing enzyme ribulose 1,5‐bisphosphate carboxylase/oxygenase (Rubisco) in dinoflagellates is difficult to study because its activity is rapidly lost after extraction from the cell. We report procedures for the extraction of Rubisco from Symbiodinium cells and for stable storage. We describe a continuous assay for Rubisco activity in these crude cell extracts using the Mn²⁺ chemiluminescence of Rubisco oxygenase. Chemiluminescence time courses exhibited initial transients resembling bacterial Form II Rubisco, followed by several minutes of linearly decreasing activity. The initial activity was determined from extrapolation of this linear section of the time course. The activity of fast‐frozen cell extracts was stable at ?80 °C and, after thawing and storage on ice, remained stable for up to 1 h before declining non‐linearly. Crude cell extracts bound [¹⁴C] 2‐carboxy‐D‐arabitinol 1,5‐bisphosphate to a high molecular mass fraction separable by gel filtration chromatography. After pre‐treatment of Symbiodinium cell cultures in darkness at temperatures above 30 °C, the extracted Rubisco activities decreased, with almost complete loss of activity above 36 °C. The implications for the sensitivity to elevated temperature of Symbiodinium photosynthesis are assessed.     

The social elite: Habitat heterogeneity,complexity and quality in granite inselbergs influence patterns of aggregation in Egernia striolata (Lygosominae: Scincidae)

Habitat heterogeneity, structural complexity and habitat quality are key features of the environment that drive species' distribution and patterns of biological organization. Traditionally, pattern‐based studies have focused on faunal responses to biological systems. However, the influence of non‐biological environments such as insular rock outcrops on patterns of vertebrate distribution is conceivably as important, but has received less attention. Granite inselbergs are a naturally heterogeneous and spatially‐limited habitat. As such, they provide an opportunity for investigating whether environmental attributes influence social behaviour in animals that use these kinds of habitat, particularly lizards that are well adapted to saxicoline environments. We applied ecological theory to investigate the influence of habitat heterogeneity, structural complexity and habitat quality on patterns of home‐site occupancy in the crevice skink Egernia striolata (Lygosominea: Scincidae) from insular granite outcrops located within fragmented agricultural landscapes. We compared home‐site occupancy among solitary juveniles, solitary adults and lizard aggregations. We found significant differences in home‐site occupancy between aggregations and solitary lizard outcrop attributes measured at multiple spatial scales. The probability of a home‐site being occupied by an aggregation increased where large rock masses were present, on northern aspects near the core of the outcrop and in structurally variegated landscapes. Significantly more aggregations occupied home‐sites surrounded by high boulder cover and crevice microhabitat. We provide evidence that geophysical attributes of granite inselbergs and landscape context can influence patterns of lizard aggregation. Thus, we clearly document the environmental correlations of variability in sociality among subpopulations of Egernia striolata.     

Antibiotic anaphylaxis

Pulmonary cancer when localized to the lung, is curable by operation. Tumors found by routine x-ray examination before they cause symptoms are much more often confined to the lung and as such are curable. Unlike other internal growths which are more hidden, lung tumors can often be seen early on x-ray films of the chest.X-ray films of the chest were made routinely on all patients entering a hospital, regardless of the nature of their illness. In all, some 40,000 films were made. Sixty patients were found to have unsuspected solitary lesions in the lung. Twenty-four of the lesions were diagnosed and treated by operation and removal. Twelve were diagnosed by other methods. Of the 36, eight were cancer of the lung, an incidence of 22 per cent. There were also 14 localized tuberculous nodules which are best treated by removal. Since early cancer is surgically curable, it is felt that everyone over the age of 40 should have a routine x-ray examination of the chest every six months. Solitary lesions of the lung found should be excised for diagnosis.     

Continental and ecological variance components of European and North American Atlantic salmon (Salmo salar) phenotypes

Juvenile Atlantic salmon ( Salmo salar ) meristic and morphometric characteristics were examined from 47 European and North American river populations. The relative importance of continental origin, stream gradient, overall temperature regime, and seasonal temperatures in explaining the phenotypic variation of these populations was evaluated using multi-way ANOVA. Ecological factors explained a greater percentage of the variance than continental origin for both meristic and morphometric characters. Stream gradient was the most important factor explaining morphometric variation and April-May mean temperature was the most important factor explaining meristic variation.     

Changes in soil carbon and nitrogen properties and microbial communities in relation to growth of Pinus radiata and Nothofagus fusca trees after 6 years at ambient and elevated atmospheric CO2

Increasing atmospheric CO₂ concentration can influence the growth and chemical composition of many plant species, and thereby affect soil organic matter pools and nutrient fluxes. Here, we examine the effects of ambient (initially 362 μL L^?1) and elevated (654 μL L^?1) CO₂ in open‐top chambers on the growth after 6 years of two temperate evergreen forest species: an exotic, Pinus radiata D. Don, and a native, Nothofagus fusca (Hook. F.) Oerst. (red beech). We also examine associated effects on selected carbon (C) and nitrogen (N) properties in litter and mineral soil, and on microbial properties in rhizosphere and hyphosphere soil. The soil was a weakly developed sand that had a low initial C concentration of about 1.0 g kg^?1 at both 0–100 and 100–300 mm depths; in the N. fusca system, it was initially overlaid with about 50 mm of forest floor litter (predominantly FH material) taken from a Nothofagus forest. A slow‐release fertilizer was added during the early stages of plant growth; subsequent foliage analyses indicated that N was not limiting. After 6 years, stem diameters, foliage N concentrations and C/N ratios of both species were indistinguishable (P>0.10) in the two CO₂ treatments. Although total C contents in mineral soil at 0–100 mm depth had increased significantly (P<0.001) after 6 years growth of P. radiata, averaging 80±0.20 g m^?2 yr^?1, they were not significantly influenced by elevated CO₂. However, CO₂‐C production in litter, and CO₂‐C production, microbial C, and microbial C/N ratios in mineral soil (0–100 mm depth) under P. radiata were significantly higher under elevated than ambient CO₂. CO₂‐C production, microbial C, and numbers of bacteria (but not fungi) were also significantly higher under elevated CO₂ in hyphosphere soil, but not in rhizosphere soil. Under N. fusca, some incorporation of the overlaid litter into the mineral soil had probably occurred; except for CO₂‐C production and microbial C in hyphosphere soil, none of the biochemical properties or microbial counts increased significantly under elevated CO₂. Net mineral‐N production, and generally the potential utilization of different substrates by microbial communities, were not significantly influenced by elevated CO₂ under either tree species. Physiological profiles of the microbial communities did, however, differ significantly between rhizosphere and hyphosphere samples and between samples under P. radiata and N. fusca. Overall, results support the concept that a major effect on soil properties after prolonged exposure of trees to elevated CO₂ is an increase in the amounts, and mineralization rate, of labile organic components.     

Promotion of Flowering in the Pinaceae by Gibberellins

Flowering was significantly promoted in 4-year-old grafts of mature coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) clones by exogenous gibberellins (GAs) A₄ and A₇ (as a mixture) applied alone and in combination with A₅ and A₉. Biweekly applications of 400 μg GA_4/7 per branch between late March and late June gave a 5-fold increase in ovulate and 3-fold increase in staminate strobilus production over untreated controls. ⁶N-benzyladenine and 2,3,5-triiodobenzoic acid applied in combination with GAs had no consistent effect on strobilus production. Non-destructive branch girdling, ineffective by itself as a cultural treatment, enhanced the GA benefit to flowering. Exogenous application of GA_4/7 is effective and appears to be a practical method for promotion of early and enhanced flowering in grafted Douglas-fir seed orchards.     

Airborne laser scanning for vegetation structure quantification in a south east Australian scrubby forest‐woodland

Airborne laser scanning (ALS) has the potential to capture a range vegetation structural metrics, but most studies have focussed on conifer or mixed conifer‐deciduous cool‐temperate or boreal forests. This study focuses on a warm‐temperate eucalypt forest, where two epochs of ALS data, captured approximately 2 years apart, were compared with plot and transect field data collected after the second ALS epoch. Linear regression was used to compare metrics from field and ALS data, and Student's t‐tests were used to compare metrics from the two ALS epochs. Statistically significant relationships were found for tree height (R² = 0.915; SE = 2.08 m; P < 0.01) and canopy cover (R² = 0.508; SE = 16.4%; P < 0.01). Foliage projective cover was also significantly correlated (R² = 0.916; SE = 4.5%; P < 0.01) at a 10‐m stratification, but not at the typically computed 2‐m stratification, because of the presence of a tall scrubby understorey. Statistically significant values were also obtained from ALS data captured 2 years earlier, although correlation was not as strong, most likely because of the greater interval between fieldwork and ALS capture. Importantly, significant agreement was found for all metrics when the two ALS epochs were compared, suggesting that the metrics are robust.