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201.
Leo Couacaud 《Anthropological Forum》2015,25(1):42-65
Avoidance relations between male kin are a pervasive social phenomenon, yet the subject has received comparatively little treatment in the anthropological literature. When anthropologists have addressed it, they have usually done so indirectly, or put forward theories better suited to explaining other social phenomena. The most common explanations one comes across in the anthropological literature to account for avoidance relationships between male kin, or what I also describe as same-sex avoidance relations in the paper, are the incest taboo and Radcliffe-Brown's theory of respect. In contrast to these explanations, I propose to demonstrate that the reason male kin avoid each other in certain types of settings is not just to maintain a sense of authority and precedence as Radcliffe-Brown's theory implies, or to avoid contravening incest prohibitions, which as Robert Lowie pointed out long ago is incorrect. Rather, because closely related male kin should not compete with each other, as this would contravene the ideology of descent which demands loyalty to one's kin. 相似文献
202.
Thirty-one compounds, including fourteen triterpenoids (1–14), seven coumarins (15–21), four lignans (22–25), and six diterpenes (26–31) were isolated from the aerial part of Euphorbia hirta. The structures were elucidated by spectroscopic methods and by comparison of their reported spectroscopic data. These compounds have shown the chemical relationships between this plant and other species from the genus Euphorbia. 相似文献
203.
Molecular phylogenetic relationships among Asiatic shrewlike moles inferred from the complete mitogenomes
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Robert W. Murphy Shunde Chen Xiuyue Zhang Chaochao Yan Yang Liu Zhiyu Sun Jianrong Fu Shaoying Liu Bisong Yue 《Journal of Zoological Systematics and Evolutionary Research》2015,53(2):155-160
Asiatic shrewlike moles are distributed almost entirely in south‐west China; four of the five species of the genus Uropsilus, Uropsilus aequodonenia, U. andersoni, U. investigator and U. soricipes are endemic to China. Excluding the five species, three cryptic species (U. sp. 1, U. sp. 2 and U. sp. 3) and two putative species, U. nivatus and U. atronates, are recognized. The phylogenetic relationships among the species remain unclear and these preclude investigations of their potential adaptations for living in high altitudes. We sequenced the complete mitochondrial DNA genomes of three species of Asiatic shrewlike moles (U. aequodonenia, U. andersoni and U. nivatus). Phylogenetic analyses of 16 published and our de novo mitogenomes yield single, robust trees with the relationships being (U. soricipes (U. sp. 1 (U. nivatus (U. andersoni, U. aequodonenia)))). Further, the tree verifies the validity of recently described U. aequodonenia. Analyses of selection pressure suggest that the 13 mtDNA‐encoding genes of species in the genus Uropsilus all have experienced strong purifying selection, although ATP8 accumulated a higher ratio of non‐synonymous substitutions than the other loci, which might reflect adaptation of the genus Uropsilus to different environments/elevations. 相似文献
204.
205.
Rafael L. Rodríguez Jennifer Danzy Cramer Christopher A. Schmitt Tegan J. Gaetano J. Paul Grobler Nelson B. Freimer Trudy R. Turner 《Biological journal of the Linnean Society. Linnean Society of London》2015,114(3):527-537
Sexual traits vary tremendously in static allometry. This variation may be explained in part by body size‐related differences in the strength of selection. We tested this hypothesis in two populations of vervet monkeys, using estimates of the level of condition dependence for different morphological traits as a proxy for body size‐related variation in the strength of selection. In support of the hypothesis, we found that the steepness of allometric slopes increased with the level of condition dependence. One trait of particular interest, the penis, had shallow allometric slopes and low levels of condition dependence, in agreement with one of the most consistent patterns yet detected in the study of allometry, namely that of genitalia exhibiting shallow allometries. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 527–537. 相似文献
206.
Response of wheat restricted‐tillering and vigorous growth traits to variables of climate change
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Eduardo A. Dias de Oliveira Kadambot H. M. Siddique Helen Bramley Katia Stefanova Jairo A. Palta 《Global Change Biology》2015,21(2):857-873
The response of wheat to the variables of climate change includes elevated CO2, high temperature, and drought which vary according to the levels of each variable and genotype. Independently, elevated CO2, high temperature, and terminal drought affect wheat biomass and grain yield, but the interactive effects of these three variables are not well known. The aim of this study was to determine the effects of elevated CO2 when combined with high temperature and terminal drought on the high‐yielding traits of restricted‐tillering and vigorous growth. It was hypothesized that elevated CO2 alone, rather than combined with high temperature, ameliorates the effects of terminal drought on wheat biomass and grain yield. It was also hypothesized that wheat genotypes with more sink capacity (e.g. high‐tillering capacity and leaf area) have more grain yield under combined elevated CO2, high temperature, and terminal drought. Two pairs of sister lines with contrasting tillering and vigorous growth were grown in poly‐tunnels in a four‐factor completely randomized split‐plot design with elevated CO2 (700 µL L?1), high day time temperature (3 °C above ambient), and drought (induced from anthesis) in all combinations to test whether elevated CO2 ameliorates the effects of high temperature and terminal drought on biomass accumulation and grain yield. For biomass and grain yield, only main effects for climate change variables were significant. Elevated CO2 significantly increased grain yield by 24–35% in all four lines and terminal drought significantly reduced grain yield by 16–17% in all four lines, while high temperature (3 °C above the ambient) had no significant effect. A trade‐off between yield components limited grain yield in lines with greater sink capacity (free‐tillering lines). This response suggests that any positive response to predicted changes in climate will not overcome the limitations imposed by the trade‐off in yield components. 相似文献
207.
Inclusion of ecologically based trait variation in plant functional types reduces the projected land carbon sink in an earth system model
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Lieneke M. Verheijen Rien Aerts Victor Brovkin Jeannine Cavender‐Bares Johannes H. C. Cornelissen Jens Kattge Peter M. van Bodegom 《Global Change Biology》2015,21(8):3074-3086
Earth system models demonstrate large uncertainty in projected changes in terrestrial carbon budgets. The lack of inclusion of adaptive responses of vegetation communities to the environment has been suggested to hamper the ability of modeled vegetation to adequately respond to environmental change. In this study, variation in functional responses of vegetation has been added to an earth system model (ESM) based on ecological principles. The restriction of viable mean trait values of vegetation communities by the environment, called ‘habitat filtering’, is an important ecological assembly rule and allows for determination of global scale trait–environment relationships. These relationships were applied to model trait variation for different plant functional types (PFTs). For three leaf traits (specific leaf area, maximum carboxylation rate at 25 °C, and maximum electron transport rate at 25 °C), relationships with multiple environmental drivers, such as precipitation, temperature, radiation, and CO2, were determined for the PFTs within the Max Planck Institute ESM. With these relationships, spatiotemporal variation in these formerly fixed traits in PFTs was modeled in global change projections (IPCC RCP8.5 scenario). Inclusion of this environment‐driven trait variation resulted in a strong reduction of the global carbon sink by at least 33% (2.1 Pg C yr?1) from the 2nd quarter of the 21st century onward compared to the default model with fixed traits. In addition, the mid‐ and high latitudes became a stronger carbon sink and the tropics a stronger carbon source, caused by trait‐induced differences in productivity and relative respirational costs. These results point toward a reduction of the global carbon sink when including a more realistic representation of functional vegetation responses, implying more carbon will stay airborne, which could fuel further climate change. 相似文献
208.
Habitat destruction is driving biodiversity loss in remaining ecosystems, and ecosystem functioning and services often directly depend on biodiversity. Thus, biodiversity loss is likely creating an ecosystem service debt: a gradual loss of biodiversity‐dependent benefits that people obtain from remaining fragments of natural ecosystems. Here, we develop an approach for quantifying ecosystem service debts, and illustrate its use to estimate how one anthropogenic driver, habitat destruction, could indirectly diminish one ecosystem service, carbon storage, by creating an extinction debt. We estimate that c. 2–21 Pg C could be gradually emitted globally in remaining ecosystem fragments because of plant species loss caused by nearby habitat destruction. The wide range for this estimate reflects substantial uncertainties in how many plant species will be lost, how much species loss will impact ecosystem functioning and whether plant species loss will decrease soil carbon. Our exploratory analysis suggests that biodiversity‐dependent ecosystem service debts can be globally substantial, even when locally small, if they occur diffusely across vast areas of remaining ecosystems. There is substantial value in conserving not only the quantity (area), but also the quality (biodiversity) of natural ecosystems for the sustainable provision of ecosystem services. 相似文献
209.
210.
Macroalgae in estuarine and coastal waters, in contrast to vascular salt marsh plants, have previously been utilised as biomonitors of sediment-held metals. The colonising halophyte Salicornia spp., however, occurs in both mudflats alongside macroalgae, as well as in association with salt marsh vascular plants. The present research aims to determine the relationships between fluctuations in sediment-held metals and those in Salicornia spp. over the course of a growing season. Samples of the species and corresponding underlying sediment were collected from the metal mine-polluted Restronguet Creek of the Fal Estuary, Cornwall on a monthly basis between March and November, 2000. Oven-dried sediment and vegetation samples were analysed for total Fe, Cu, Zn and Mn. Significant correlations with both the roots and aerial portion of the plant were found with sediment Cu and Zn concentrations. Significant relationships with either Mn or Fe were not observed. Thus, Salicornia spp. would appear to be a suitable tool for biomonitoring Zn and, particularly, Cu. Hyperaccumulation of Zn in the aerial portion during initial growth also indicates that Salicornia spp. may be useful for alleviating metal contamination through phytoextraction, whilst Cu in the roots is proposed as having potential for phytostabilization. 相似文献