TOWARD AN EVOLUTIONARY DEFINITION OF CHEATING

The term “cheating” is used in the evolutionary and ecological literature to describe a wide range of exploitative or deceitful traits. Although many find this a useful short hand, others have suggested that it implies cognitive intent in a misleading way, and is used inconsistently. We provide a formal justification of the use of the term “cheat” from the perspective of an individual as a maximizing agent. We provide a definition for cheating that can be applied widely, and show that cheats can be broadly classified on the basis of four distinctions: (i) whether cooperation is an option; (ii) whether deception is involved; (iii) whether members of the same or different species are cheated; and (iv) whether the cheat is facultative or obligate. Our formal definition and classification provide a framework that allow us to resolve and clarify a number of issues, regarding the detection and evolutionary consequences of cheating, as well as illuminating common principles and similarities in the underlying selection pressures.     

基于资源与环境保护的煤炭开发功能区划

以往的煤炭开发规划,均未充分考虑发展循环经济和加强生态保护等因素,不利于统筹安排区域层次上的环境保护工作.本文在综合分析区域生态状况、区位条件和经济发展水平等因素的基础上,以资源和环境保护为出发点,将全国的煤炭资源富集区划分为重点开发区、适度开发区和限制开发区3种功能区.结合自然地理条件和生态特征,进一步划分为黄土高原丘陵沟壑区、平原矿粮复合区、云贵山地丘陵区、西北荒漠草原区和蒙东森林草原、草甸草原区等5种典型类型区,针对不同的分区,分别提出了相应的环境保护对策.     

甘肃省药用植物秦艽野生资源现状及开发利用

甘肃省是秦艽的原产地之一,蕴藏着丰富的野生资源.由于不合理的采挖利用,致使资源遭到破坏.对甘肃省秦艽野生资源的种类、分布及生态环境特征、生长情况、采挖与收购现状进行了阐述,并提出了合理开发利用的对策.     

Do Australian small mammals respond to native and introduced predator odours?

Abstract Coevolution is thought to have led to many small mammal species avoiding the scent marks of their main mammalian predators, as they provide a reliable cue to predation risk. Most support for this hypothesis comes from northern hemisphere predator/prey systems, however, it is unclear whether this avoidance of predator faecal odour occurs in Australia's mammalian fauna, which has evolved in relative isolation from the rest of the world, and is dominated by marsupials rather than placentals. We tested this theory for an Australian system with marsupial and placental predators and prey, that share a long‐term (>1 million years) or short‐term (<150 years) exposure to each other. The predators were the native marsupial tiger quoll Dasyurus maculatus and the introduced placental red fox Vulpes vulpes. The potential prey were three native rodent species, the bush rat Rattus fuscipes, the swamp rat Rattus lutreolus, the eastern chestnut mouse Pseudomys gracilicaudatus, and the marsupial brown antechinus Antechinus stuartii. Small mammals were captured in Elliott traps with 1/3 of traps treated with fox faeces, 1/3 treated with quoll faeces and the remainder left untreated. The native rodent species all showed avoidance of both tiger quoll and red fox odours whereas the marsupial antechinus showed no responses to either odour. Either predator odour avoidance has not evolved in this marsupial or their reaction to predator odours may be exhibited in ways which are not recognizable through trapping. The avoidance by the rodents of fox odour as well as quoll odour indicates this response may either be due to common components in fox and quoll odour, or it may be a recently evolved response.     

Could controlling mammalian carnivores lead to mesopredator release of carnivorous reptiles?

Emerging evidence increasingly illustrates the importance of a holistic, rather than taxon-specific, approach to the study of ecological communities. Considerable resources are expended to manage both introduced and native mammalian carnivores to improve conservation outcomes; however, management can result in unforeseen and sometimes catastrophic outcomes. Varanid lizards are likely to be apex- or mesopredators, but being reptiles are rarely considered by managers and researchers when investigating the impacts of mammalian carnivore management. Instances of mesopredator release have been described for Varanus gouldii as a result of fox and cat management in Australia, with cascading effects on faunal community structure. A meta-analysis showing extensive dietary niche overlap between varanids, foxes and cats plus a review of experimental and circumstantial evidence suggests mesopredator release of V. gouldii and about five other medium to large species of varanid lizard is likely in other regions. This highlights the need for managers to adopt a whole-of-community approach when attempting to manage predators for sustained fauna conservation, and that additional research is required to elucidate whether mesopredator release of varanids is a widespread consequence of carnivore management, altering the intended faunal responses.     

Evolution of the limpet Patella candei d'Orbigny (Mollusca, Patellidae) in Atlantic archipelagos: human intervention and natural processes

The genetic and morphological structure of Patella candei in the Macaronesian Islands were studied by allozyme electrophoresis and multivariate analysis (canonical discriminant analysis), respectively. Sixteen enzymes, yielding 21 resolvable loci were analysed for all populations using the BIOSYS-1 program. A disjunct distribution of genetically similar populations from the Azores and Selvagens Islands ( P.c. gomesii – P.c. candei ) was found, which showed two diagnostic loci with P.c. ordinaria from Madeira. Patella c. crenata from the Canaries showed an intermediate composition of 92% P.c. ordinaria and 8% P.c. gomesii–P.c. candei . Hypotheses are presented to explain the evolution of the genetic and morphological structure of P.c. candei in the Macaronesian Islands, including the interaction of natural processes and human intervention. Patella c. candei is considered to represent the ancestral form. An extinction or near extinction event may have happened in Madeira after which P.c. ordinaria arose, carrying only a small part of the diversity of the original form, which evolved in isolation. The ancestral form, P.c. candei , was depleted by human extraction from high levels of the shore in the Azores and Canaries. Patella c. gomesii , from the Azores evolved by phyletic evolution, colonizing low levels of the shore, leaving only a relict population in the Selvagens Islands, that remained almost free of human exploitation. Patella c. crenata is a hybrid with a high degree of introgression to P.c. ordinaria , which is maintained by the forces of human extraction at high-tide levels and by intraspecific competition at low-tide levels.  © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 77 , 341−353.     

Forecasting spatially structured populations: the role of dispersal and scale

We forecasted spatially structured population models with complex dynamics, focusing on the effect of dispersal and spatial scale on the predictive capability of nonlinear forecasting (NLF). Dispersal influences NLF ability by its influence on population dynamics. For simple 2-cell models, when dispersal is small, our ability to predict abundance in subpopulations decreased and then increased with increasing dispersal. Spatial heterogeneity, dispersal manner, and environmental noise did not qualitatively change this result. But results are not clear for complex spatial configurations because of complicated dispersal interactions across subpopulations. Populations undergoing periodic fluctuations could be forecasted perfectly for all deterministic cases that we studied, but less reliably when environmental noise was incorporated. More importantly, for all models that we have examined, NLF was much worse at larger spatial scales as a consequence of the asynchronous dynamics of subpopulations when the dispersal rate was below some critical value. The only difference among models was the critical value of dispersal rate, which varied with growth rate, carrying capacity, mode of dispersal, and spatial configuration. These results were robust even when environmental noise was incorporated. Intermittency, common in the dynamics of spatially structured populations, lowered the predictive capability of NLF. Forecasting population behaviour is of obvious value in resource exploitation and conservation. We suggest that forecasting at local scales holds promise, whereas forecasting abundance at regional scales may yield poor results. Improved understanding of dispersal can enhance the management and conservation of natural resources, and may help us to understand resource-exploitation strategies employed by local indigenous humans.