Heritability of short-scale natal dispersal in a large-scale foraging bird, the wandering albatross

Natal dispersal is a key life history trait for the evolution and adaptation of wild populations. Although its evolution has repeatedly been related to the social and environmental context faced by individuals, parent-offspring regressions have also highlighted a possible heritable component. In this study, we explore heritability of natal dispersal, at the scale of the sub-Antarctic Possession Island, for a large-scale foraging seabird, the Wandering albatross Diomedea exulans, exploiting a pedigree spanning over four decades and a maximum of four generations. The comparison of three different methods shows that heritability on the liability scale can vary drastically depending on the type of model (heritability from 6% to 86%), with a notable underestimation by restricted maximum likelihood animal models (6%) compared to Bayesian animal models (36%). In all cases, however, our results point to significant additive genetic variance in the individual propensity to disperse, after controlling for substantial effects of sex and natal colony. These results reveal promising evolutionary potential for short-scale natal dispersal, which could play a critical role for the long-term persistence of this species on the long run.     

Optimal foraging for multiple nutrients in an unpredictable environment

Foraging theory has typically been concerned with the acquisition of a single resource even though organisms from mammals to protozoa are capable of balancing their requirements for multiple resources. Existing theory concerning multiple nutrients from multiple foods does not predict the sequence of food selection. We constructed an optimisation model of the simplest case of two foods containing differing amounts of two nutrients. We begin with the well-supported assumption that reproductive value declines with the distance from target nutrient intake. We show that nutrient space divides into two distinct areas where the animal should exclusively consume one food or the other. The organism thus initially concentrates on one food type until the border between the areas is reached and then moves as closely as possible along the border to approach the target. This strategy is commonly observed in a range of organisms, suggesting that the assumed fitness function is common.     

Nutritional geometry: gorillas prioritize non-protein energy while consuming surplus protein

It is widely assumed that terrestrial food webs are built on a nitrogen-limited base and consequently herbivores must compensate through selection of high-protein foods and efficient nitrogen retention. Like many folivorous primates, gorillas' diet selection supports this assumption, as they apparently prefer protein-rich foods. Our study of mountain gorillas (Gorilla beringei) in Uganda revealed that, in some periods, carbohydrate-rich fruits displace a large portion of protein-rich leaves in their diet. We show that non-protein energy (NPE) intake was invariant throughout the year, whereas protein intake was substantially higher when leaves were the major portion of the diet. This pattern of macronutrient intake suggests that gorillas prioritize NPE and, to achieve this when leaves are the major dietary item, they over-eat protein. The concentrations of protein consumed in relation to energy when leaves were the major portion of the diet were close to the maximum recommended for humans and similar to high-protein human weight-loss diets. By contrast, the concentrations of protein in relation to energy when gorillas ate fruit-dominated diets were similar to those recommended for humans. Our results question the generality of nitrogen limitation in terrestrial herbivores and provide a fascinating contrast with human macronutrient intake.     

区域水安全格局构建:研究进展及概念框架

随着全球变化背景下生态安全问题的日益严峻,生态安全格局研究成为宏观生态学关注的热点领域;水作为重要的自然生态要素,其安全格局的构建也是区域生态安全格局优化的重要组成部分,但目前其基本内涵、构建理论与方法、指标体系等尚未受到足够重视,缺乏系统梳理。在对比分析资源、环境与灾害等多学科视角下水安全概念异同的基础上,明晰了区域水安全格局的概念内涵,将其定义为保障区域水安全目标的土地利用空间格局;系统探讨了水安全格局构建历程与方法研究进展,指出水安全研究正由定量评价向空间管控转型,水环境安全格局构建严重滞后,缺乏水安全格局与自然生态过程、社会经济过程的耦合关联分析;最后,基于景观生态学格局-过程互馈理论和地理学区域综合视角,以GIS空间分析、In VEST模型等为技术支撑,构建了水资源安全、水环境安全和水灾害规避安全3个单一维度的水安全格局,并提出基于空间多准则分析模型的区域综合水安全格局构建概念框架,以期有效提升中国城市化进程的水安全格局保障。     

市县土地生态-生产-生活承载力测度指标体系及核算模型解析

土地同时具有生态功能、生产功能和生活功能,相应地具有生态-生产-生活综合承载力,土地生态承载力、生产承载力和生活承载力是一个相互支持、相互依存的有机整体。土地生态-生产-生活系统承载力是指土地资源与生态环境的供容能力、经济活动能力和满足一定生活水平人口数量的社会发展能力的有机综合体,由处于支持层的生态承载力和处于表现层的生产承载力和生活承载力三部分组成,简称土地"三生"承载力。以党的"十八大"报告提出的"优化国土空间开发格局,促进生产空间集约高效,生活空间宜居适度,生态空间山清水秀"为目标,分析了土地生态-生产-生活综合承载力的基本构成及作用机制,在此基础上,以县级尺度作为测度对象,通过多方案比选,构建了由1个一级指标、3个二级指标、21个三级指标构成的土地生态-生产-生活综合承载力测度指标体系,给出了不同层级具体指标的量化辨识方法;进一步优选出土地生态-生产-生活综合承载力核算的SD情景模型。该研究从理论上旨在为推进国土生态、生产、生活空间集约高效利用提供科学判据,为开展全国市县尺度的土地综合承载力监测预警提供定量的科学依据。     

Putting the plants back into plant ecology: six pragmatic models for understanding and conserving plant diversity

BACKGROUND: There is a compelling need to protect natural plant communities and restore them in degraded landscapes. Activities must be guided by sound scientific principles, practical conservation tools, and clear priorities. With perhaps one-third of the world's flora facing extinction, scientists and conservation managers will need to work rapidly and collaboratively, recognizing each other's strengths and limitations. As a guide to assist managers in maintaining plant diversity, six pragmatic models are introduced that are already available. Although theoretical models continue to receive far more space and headlines in scientific journals, more managers need to understand that pragmatic, rather than theoretical, models have the most promise for yielding results that can be applied immediately to plant communities. SIX PRAGMATIC MODELS: For each model, key citations and an array of examples are provided, with particular emphasis on wetlands, since "wet and wild" was my assigned theme for the Botanical Society of America in 2003. My own work may seem rather prominent, but the application and refinement of these models has been a theme for me and my many students over decades. The following models are reviewed: (1) species-area: larger areas usually contain more species; (2) species-biomass: plant diversity is maximized at intermediate levels of biomass; (3) centrifugal organization: multiple intersecting environmental gradients maintain regional landscape biodiversity; (4) species-frequency: a few species are frequent while most are infrequent; (5) competitive hierarchies: in the absence of constraints, large canopy-forming species dominate patches of landscape, reducing biological diversity; and (6) intermediate disturbance: perturbations such as water level fluctuations, fire and grazing are essential for maintaining plant diversity. CONCLUSIONS: The good news is that managers faced with protecting or restoring landscapes already have this arsenal of tools at their disposal. The bad news is that far too few of these models are appreciated.     

Antagonistic Coevolution Under Sexual Conflict

The theory of sexual conflict predicts that sexual coevolution will be very dynamic, with in principle perpetual evolutionary arms races and chases. These arms races are expected to stop once the costs of conflict adaptations become too high. We argue that this prediction is contingent on specific assumptions about the sexual interaction and the adaptations involved in the arms race. More generally, evolutionary arms races stop when the fitness benefit of further escalations is outweighed by the fitness costs. For this it is not necessary that the absolute costs of conflict must be high at the stable state, or that the population fitness must be decreased at equilibrium. We expect the outcome of sexual antagonistic coevolution to be determined by the possibility to reach compromises and by the relative ability of each sex to control the outcome of the interaction. We exemplify with a theoretical conflict model, which leads to population extinction when conflict is settled by armaments with expression-level determined costs. The model predicts a compromise with small conflict costs for the population, if costs are in addition determined by the extent of conflict between the sexes, which may be the case when the cost depends on behavioural antagonism.     

Spatial Structure of BAM-12P Dodecapeptide and Its Analogues

Theoretical conformational analysis was used to study the spatial structure and conformational properties of the bovine adrenal medulla dodecapeptide BAM-12P (Tyr1-Gly2-Gly3-Phe4-Met5-Arg6-Arg7-Val8-Gly9-Arg10-Pro11-Glu12). Twenty-three low-energy conformations of the BAM-12P backbone were shown to represent the spatial structure of the peptide. The inverse structural problem was solved, and synthetic analogues of BAM-12P were proposed, the spatial structures of which correspond to a set of low-energy potentially physiologically active conformations of the natural dodecapeptide.__________Translated from Bioorganicheskaya Khimiya, Vol. 31, No. 3, 2005, pp. 245–250.Original Russian Text Copyright © 2005 by Akhmedov, Tagiev, Hasanov, Makhmudova.     

Theoretical Study of the Structure of Adenosine Deaminase Complexes with Adenosine Analogues: I. Aza-, Deaza-, and Isomeric Azadeazaanalogues of Adenosine

Conformational models of the active site of adenosine deaminase (ADA) and its complexes in the basic state with adenosine and 13-isosteric analogues of the aza, deaza, and azadeaza series were constructed. The optimization of the conformational energy of the active site and the nucleoside bound with it in the complex was achieved in the force field of the whole enzyme [the structure of ADA complex with 1-deazaadenosine (1ADD) was used] within the molecular mechanics model using the AMBER 99 potentials. The stable conformational states of each of the complexes, as well as the optimal conformation of ADA in the absence of ligand, were determined. It was proved that the conformational state that is close to the structure of the ADA complex with 1ADD known from X-ray study corresponds to one of the local minima of the potential surface. Another, a significantly deeper minimum was determined; it differs from the first minimum by the mutual orientation of side chains of amino acid residues. A similar conformational state is optimal for the ADA active site in the absence of bound ligand. A qualitative correlation exists between the values of potential energies of the complexes in this conformation and the enzymatic activity of ADA toward the corresponding nucleosides. The dynamics of conformational conversions of the active site after the binding of substrate or its analogues, as well as the possibility of the estimation of the inhibitory properties of nucleosides on the basis of calculations, are discussed.     

Two-dimensional Cu and first Pb coordination polymers based on a flexible 1,4-cyclohexanedicarboxylate ligand displaying different conformations and coordination modes

Two novel metal-organic hybrid coordination polymers {[Cu(bpo)(chdc)(H₂O)](H₂O)_0.5}_n (1) and [Pb(chdc)(H₂O)]_n (2) have been synthesized under different conditions and structurally characterized by single-crystal X-ray diffraction technique, where H₂chdc refers to a flexible 1,4-cyclohexanedicarboxylic acid ligand and bpo is 2,5-bis(4-pyridyl)-1,3,4-oxadiazole. Complex 1 has a two-dimensional (2-D) grid-like [11.28 × 13.63 Å²] framework in which the Cu^II centers are extended via bidentate bridging ligands bpo and e,e-trans-chdc along two directions, exhibiting large porous cavities. Coordination polymer 2 represents the first Pb^II complex of H₂chdc in which the larger Pb^II centers are connected by e,a-cis-chdc anions to afford a 2-D close-knit structure.