Artificial selection for predatory behavior results in dietary niche differentiation in an omnivorous mammal

The diet of an individual is a result of the availability of dietary items and the individual's foraging skills and preferences. Behavioral differences may thus influence diet variation, but the evolvability of diet choice through behavioral evolution has not been studied. We used experimental evolution combined with a field enclosure experiment to test whether behavioral selection leads to dietary divergence. We analysed the individual dietary niche via stable isotope ratios of nitrogen (δ15N) and carbon (δ13C) in the hair of an omnivorous mammal, bank vole, from 4 lines selected for predatory behavior and 4 unselected control lines. Predatory voles had higher hair δ15N values than control voles, supporting our hypothesis that predatory voles would consume a higher trophic level diet (more animal vs. plant foods). This difference was significant in the early but not the late summer season. The δ13C values also indicated a seasonal change in the consumed plant matter and a difference in food sources among selection lines in the early summer. These results imply that environmental factors interact with evolved behavioral tendencies to determine dietary niche heterogeneity. Behavioral selection thus has potential to contribute to the evolution of diet choice and ultimately the species' ecological niche breadth.

Cellulose in atmospheric particulate matter

The spatiotemporal variations of free cellulose concentrations in atmospheric particles, as a proxy for plant debris, were investigated using a novel HPLC-PAD method. Filter samples were taken from nine sites of varying characteristics across France and Switzerland, with sampling covering all seasons. Concentrations of cellulose, as well as carbonaceous aerosol and other source-specific chemical tracers (e.g. Elemental Carbon (EC), levoglucosan, polyols, trace metals, and glucose) were quantified. Annual mean free cellulose concentrations within PM10 ranged from 29 ± 38 ng m−3 at Bern (urban site) to 284 ± 225 ng m−3 at Payerne (rural site). Concentrations were considerably higher during episodes, with spikes exceeding 1150 and 2200 ng m−3 at Payerne and ANDRA-OPE (rural site), respectively. A clear seasonality, with highest cellulose concentrations during summer and autumn, was observed at all rural and some urban sites. However, some urban locations exhibited a weakened seasonality. Contributions of cellulose-carbon to total organic carbon are moderate on average (0.7–5.9 %), but much greater during ‘episodes’, reaching close to 20 % at Payerne. Cellulose concentrations correlated poorly between sites, even a ranges of about 10 km, indicating the localised nature of the sources of atmospheric plant debris. With regards to these sources, correlations between cellulose and typical biogenic chemical tracers (polyols and glucose) were moderate to strong (Rs 0.28−0.78, p < 0.0001) across the nine sites. Seasonality was strongest at sites with stronger biogenic correlations, suggesting the main source of cellulose arises from biogenic origins. A second input to ambient plant debris concentrations was suggested via resuspension of plant matter at several urban sites, due to moderate cellulose correlations with mineral dust tracers, Ca2+ and Ti metal (Rs 0.28−0.45, p < 0.007). No correlation was obtained with the biomass burning tracer (levoglucosan), an indication that this is not a source of atmospheric cellulose. Finally, an investigation into the interannual variability of atmospheric cellulose across the Grenoble metropole area was completed. It was shown that concentrations and sources of ambient cellulose can vary considerably between years. All together, these results deeply improve our knowledge on the phenomenology of plant debris within ambient air.

Stable Isotope Geochemistry of Paleocene to Early Eocene Strata around Southern New Zealand

<p>The Late Teurian (Paleocene) Tartan Formation is an organic-rich mudstone that has been identified in five of the eight exploration wells drilled in the Great South Basin, and three of four exploration wells drilled in the Canterbury Basin. In this study, the geochemistry of two wells from the Great South Basin (Pukaki-1 and Rakiura-1) and four wells from the Canterbury Basin in southern New Zealand (Resolution-1, Clipper-1, Galleon-1, and Endeavour-1) have been investigated using elemental analyser isotope ratio mass spectrometric (EA-IRMS) analyses on selected sidewall core and cuttings samples. This study builds on previous geochemical work by the author from five other wells from the Great South Basin (Takapu-1A, Toroa-1, Pakaha-1, Kawau-1A, and Hoiho-1C). All wells except Rakiura-1, Takapu-1A, and Resolution-1 showed geochemical characteristics that allowed recognition of the Tartan Formation. The formation is characterised by enrichments in TOC (typically above 3%) and 13C (generally delta13C ratios are between -21 and -17 per 1000), indicating a significant marine contribution. C/N ratios recorded within the Tartan Formation are all above 20, which suggest that the organic matter contains a significant contribution from terrestrial and/or altered marine material. Geochemical evidence of samples within the Tartan Formation suggests that it contains a mixture of marine bacterial/plant/algal and C3 terrestrial plant source components. This is consistent with the findings of Killops et al. (2000), who reported from biomarker studies that the organic matter of some Great South Basin samples contained organic matter derived from a marine source with varying degrees of terrestrial contribution. The Tartan Formation is distinct from enclosing formations which are characterised by low organic contents (generally below 2%), isotopically light delta13C values (typically around -26 per 1000), which is indicative of terrestrial C3 plant matter, and a wide range of C/N ratios (ranging from 4 to 64). The latter suggests that there were varying degrees of preservation of the deposited organic matter within these formations. Organic matter within enclosing formations appears to be derived from a combination of C3 land plants and marine material. The high TOC content of Tartan Formation sediments compared to the underlying formation suggests that it represents a profound change in depositional conditions. Conditions for the preservation and accumulation of organic matter were more favorable prior to deposition of the Tartan Formation than following it. The enrichment of 13C and the high TOC contents within the Tartan Formation are similar to those for the mid to Late Teurian Waipawa Formation that has been identified throughout many of New Zealand's major sedimentary basins; however, TOC and delta13C values for the Tartan Formation exceed those previously reported for the Waipawa Formation. Geochemical changes characteristic of the Tartan Formation are recognised below the lithological base of the formation in some wells, contemporaneous with the onset of the Paleocene Carbon Isotope Maximum (PCIM), and represent different lithostratigraphic expressions of that event. Termination of the environmental effects associated with the PCIM around New Zealand appears to have been diachronous and differences between the exact ages and stratigraphic positions of the Tartan and Waipawa formations are attributed to local environmental variations during deposition. TOC and delta13C enrichments associated with the Tartan Formation are not ubiquitous, and the formation has variable thickness throughout the Great South and Canterbury basins. It is concluded that the Tartan and Waipawa formations are correlatives.</p>

Stable Isotope Geochemistry of Paleocene to Early Eocene Strata around Southern New Zealand

<p>The Late Teurian (Paleocene) Tartan Formation is an organic-rich mudstone that has been identified in five of the eight exploration wells drilled in the Great South Basin, and three of four exploration wells drilled in the Canterbury Basin. In this study, the geochemistry of two wells from the Great South Basin (Pukaki-1 and Rakiura-1) and four wells from the Canterbury Basin in southern New Zealand (Resolution-1, Clipper-1, Galleon-1, and Endeavour-1) have been investigated using elemental analyser isotope ratio mass spectrometric (EA-IRMS) analyses on selected sidewall core and cuttings samples. This study builds on previous geochemical work by the author from five other wells from the Great South Basin (Takapu-1A, Toroa-1, Pakaha-1, Kawau-1A, and Hoiho-1C). All wells except Rakiura-1, Takapu-1A, and Resolution-1 showed geochemical characteristics that allowed recognition of the Tartan Formation. The formation is characterised by enrichments in TOC (typically above 3%) and 13C (generally delta13C ratios are between -21 and -17 per 1000), indicating a significant marine contribution. C/N ratios recorded within the Tartan Formation are all above 20, which suggest that the organic matter contains a significant contribution from terrestrial and/or altered marine material. Geochemical evidence of samples within the Tartan Formation suggests that it contains a mixture of marine bacterial/plant/algal and C3 terrestrial plant source components. This is consistent with the findings of Killops et al. (2000), who reported from biomarker studies that the organic matter of some Great South Basin samples contained organic matter derived from a marine source with varying degrees of terrestrial contribution. The Tartan Formation is distinct from enclosing formations which are characterised by low organic contents (generally below 2%), isotopically light delta13C values (typically around -26 per 1000), which is indicative of terrestrial C3 plant matter, and a wide range of C/N ratios (ranging from 4 to 64). The latter suggests that there were varying degrees of preservation of the deposited organic matter within these formations. Organic matter within enclosing formations appears to be derived from a combination of C3 land plants and marine material. The high TOC content of Tartan Formation sediments compared to the underlying formation suggests that it represents a profound change in depositional conditions. Conditions for the preservation and accumulation of organic matter were more favorable prior to deposition of the Tartan Formation than following it. The enrichment of 13C and the high TOC contents within the Tartan Formation are similar to those for the mid to Late Teurian Waipawa Formation that has been identified throughout many of New Zealand's major sedimentary basins; however, TOC and delta13C values for the Tartan Formation exceed those previously reported for the Waipawa Formation. Geochemical changes characteristic of the Tartan Formation are recognised below the lithological base of the formation in some wells, contemporaneous with the onset of the Paleocene Carbon Isotope Maximum (PCIM), and represent different lithostratigraphic expressions of that event. Termination of the environmental effects associated with the PCIM around New Zealand appears to have been diachronous and differences between the exact ages and stratigraphic positions of the Tartan and Waipawa formations are attributed to local environmental variations during deposition. TOC and delta13C enrichments associated with the Tartan Formation are not ubiquitous, and the formation has variable thickness throughout the Great South and Canterbury basins. It is concluded that the Tartan and Waipawa formations are correlatives.</p>

Multi-Media Geochemical Exploration in the Critical Zone: A Case Study over the Prairie and Wolf Zn–Pb Deposits, Capricorn Orogen, Western Australia

In this study, we compared traditional lithochemical sample media (soil) with hydrochemical (groundwater), biogeochemical (plant matter of mulga and spinifex), and other near-surface sample media (ferro-manganese crust), in a case study applied to mineral exploration in weathered terrain, through the critical zone at the fault-hosted Prairie and Wolf Zn–Pb (Ag) deposits in Western Australia. We used multi-element geochemistry analyses to spatially identify geochemical anomalies in samples over known mineralization, and investigated metal dispersion processes. In all near-surface sample media, high concentrations of the metals of interest (Zn, Pb, Ag) coincided with samples proximal to the mineralization at depth. However, the lateral dispersion of these elements differed from regional (several km; groundwater) to local (several 100′s of meters; solid sample media) scales. Zinc in spinifex leaves over the Prairie and Wolf deposits exceeded the total concentrations in all other sample media, while the metal concentrations in mulga phyllodes were not as pronounced, except for Ag, which exceeded the concentrations in all other sample media. These observations indicate potential preferential metal-specific uptake by different media. Pathfinder elements in vegetation and groundwater samples also indicated the Prairie Downs fault zone at the regional (groundwater) and local (vegetation) scale, and are, therefore, potentially useful tools to trace fault systems that host structurally controlled, hydrothermal Zn–Pb mineralization.

Estimating Organic and Inorganic Part of Suspended Solids from Sentinel 2 in Different Inland Waters

Inland waters are very sensitive ecosystems that are mainly affected by pressures and impacts within their watersheds. One of water’s dominant constituents is the suspended particulate matter that affects the optical properties of water bodies and can be detected from remote sensors. It is important to know their composition since the ecological role they play in water bodies depends on whether they are mostly organic compounds (phytoplankton, decomposition of plant matter, etc.) or inorganic compounds (silt, clay, etc.). Nowadays, the European Space Agency Sentinel-2 mission has outstanding characteristics for measuring inland waters’ biophysical variables. This work developed algorithms that can estimate the total concentration of suspended matter (TSM), differentiating organic from inorganic fractions, through the combined use of Sentinel-2 images with an extensive database obtained from reservoirs, lakes and marshes within eastern zones of the Iberian Peninsula. For this, information from 121 georeferenced samples collected throughout 40 field campaigns over a 4-year period was used. All possible two-band combinations were obtained and correlated with the biophysical variables by fitting linear regression between the field data and bands combination. The results determined that only using bands 705 or 783 lead to the obtaining the amount of total suspended matter and their organic and inorganic fractions, with errors of 10.3%, 14.8% and 12.2%, respectively. Therefore, remote sensing provides information about total suspended matter dynamics and characteristics as well as its spatial and temporal variation, which would help to study its causes.

Adapting an Ergosterol Extraction Method with Marine Yeasts for the Quantification of Oceanic Fungal Biomass

Ergosterol has traditionally been used as a proxy to estimate fungal biomass as it is almost exclusively found in fungal lipid membranes. Ergosterol determination has been mostly used for fungal samples from terrestrial, freshwater, salt marsh- and mangrove-dominated environments or to describe fungal degradation of plant matter. In the open ocean, however, the expected concentrations of ergosterol are orders of magnitude lower than in terrestrial or macrophyte-dominated coastal systems. Consequently, the fungal biomass in the open ocean remains largely unknown. Recent evidence based on microscopy and -omics techniques suggests, however, that fungi contribute substantially to the microbial biomass in the oceanic water column, highlighting the need to accurately determine fungal biomass in the open ocean. We performed ergosterol extractions of an oceanic fungal isolate (Rhodotorula sphaerocarpa) with biomass concentrations varying over nine orders of magnitude. While after the initial chloroform-methanol extraction ~87% of the ergosterol was recovered, a second extraction recovered an additional ~10%. Testing this extraction method on samples collected from the open Atlantic Ocean, we successfully determined ergosterol concentrations as low as 0.12 pM. Thus, this highly sensitive method is well suited for measuring fungal biomass from open ocean waters, including deep-sea environments.

Vapor cannabis exposure generationally affects male reproductive functions in mice

This study was performed to examine whether vapor exposure to cannabis plant matter negatively impacts male reproductive functions and testis development in mice. Adult CD-1 male mice (F0) were exposed to air (control) or 200 mg of vaporized cannabis plant matter 3x/day over a 10 day period. Subsequently, F0 males were bred with drug naive CD-1 females to generate F1 males, and F1 offspring were used to generate F2 males. Cannabis vapor exposure decreased sperm count and/or motility in F0 and F1 males and disrupted the progression of germ cell development, as morphometric analyses exhibited an abnormal distribution of the stages of spermatogenesis in F0 males. Although plasma levels of testosterone were not affected by cannabis exposure in any ages or generations of males, dysregulated steroidogenic enzymes, Cyp11a1 and Cyp19a1, were observed in F0 testis. In the neonatal testis from F1 males, while apoptosis was not altered, DNA damage and DNMT1, but not DNMT3A and DNMT3B, were increased in germ cells following cannabis exposure. In contrast, the alterations of DNA damage and DNMT1 expression were not observed in F2 neonatal males. These results suggest that cannabis vapor exposure generationally affects male reproductive functions, probably due to disruption of spermatogenesis in the developing testis.

Histology and μCT reveal the unique evolution and development of multiple tooth rows in the synapsid Endothiodon

Several amniote lineages independently evolved multiple rows of marginal teeth in response to the challenge of processing high fiber plant matter. Multiple tooth rows develop via alterations to tooth replacement in captorhinid reptiles and ornithischian dinosaurs, but the specific changes that produce this morphology differ, reflecting differences in their modes of tooth attachment. To further understand the mechanisms by which multiple tooth rows can develop, we examined this feature in Endothiodon bathystoma, a member of the only synapsid clade (Anomodontia) to evolve a multi-rowed marginal dentition. We histologically sampled Endothiodon mandibles with and without multiple tooth rows as well as single-rowed maxillae. We also segmented functional and replacement teeth in µ-CT scanned mandibles and maxillae of Endothiodon and several other anomodonts with ‘postcanine’ teeth to characterize tooth replacement in the clade. All anomodonts in our sample displayed a space around the tooth roots for a soft tissue attachment between tooth and jaw in life. Trails of alveolar bone indicate varying degrees of labial migration of teeth through ontogeny, often altering the spatial relationships of functional and replacement teeth in the upper and lower jaws. We present a model of multiple tooth row development in E. bathystoma in which labial migration of functional teeth was extensive enough to prevent resorption and replacement by newer generations of teeth. This model represents another mechanism by which multiple tooth rows evolved in amniotes. The multiple tooth rows of E. bathystoma may have provided more extensive contact between the teeth and a triturating surface on the palatine during chewing.