首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Focusing on contemporary shellfish exploitation among several atoll communities in Kiribati, Micronesia, this paper examines the relationship between human foragers and their invertebrate prey via the prey choice or diet breadth model derived from optimal foraging theory. Shellfish, like many other reef organisms, are relatively sedentary and predictable, but these characteristics make them susceptible to over-harvesting. The research reveals that shellfish gatherers are foraging in a manner that matches the predictions of optimal foraging theory. The work adds to our understanding of optimal foraging decisions in atoll settings by critically evaluating the depiction of atoll dwellers as conservationists.
Frank R. ThomasEmail: Email:
  相似文献   

2.
3.
A central reason that undergirds the significance of evo-devo is the claim that development was left out of the Modern synthesis. This claim turns out to be quite complicated, both in terms of whether development was genuinely excluded and how to understand the different kinds of embryological research that might have contributed. The present paper reevaluates this central claim by focusing on the practice of model organism choice. Through a survey of examples utilized in the literature of the Modern synthesis, I identify a previously overlooked feature: exclusion of research on marine invertebrates. Understanding the import of this pattern requires interpreting it in terms of two epistemic values operating in biological research: theoretical generality and explanatory completeness. In tandem, these values clarify and enhance the significance of this exclusion. The absence of marine invertebrates implied both a lack of generality in the resulting theory and a lack of completeness with respect to particular evolutionary problems, such as evolvability and the origin of novelty. These problems were salient to embryological researchers aware of the variation and diversity of larval forms in marine invertebrates. In closing, I apply this analysis to model organism choice in evo-devo and discuss its relevance for an extended evolutionary synthesis.
Alan C. LoveEmail:
  相似文献   

4.
The importance of mate choice and sexual selection has been emphasized by the majority of evolutionary psychologists. This paper assesses three cases of work on mate choice and sexual selection in evolutionary psychology: David Buss on cross-cultural human mate preferences, Randy Thornhill and Steve Gangestad on the link between mate preferences and fluctuating asymmetry, and Geoffrey Miller on the role of Fisher’s runaway process in human evolution. A mixture of conceptual and empirical problems in each case highlights the general weakness of work in evolutionary psychology on these issues.
Chris HaufeEmail:
  相似文献   

5.
Sub-Antarctic Marion Island has had a permanent research station for 50 years and the islands Wandering Albatrosses have been intensively studied for 20 years. The reactions of breeding birds to approaches by a human on foot were recorded. Three response variables were calculated: intensity of vocal reaction (IVR), intensity of non-vocal reaction (INR) and overall response index (ORI). At 5 m from the nest, twice as many birds stood and/or vocalised as at 15 m. Nearest neighbour distance, age and gender did not explain individual variability of responses. Study colony birds had higher IVR scores than non-study colony birds; birds at colonies closest to the station had the highest ORI scores. A better breeding record was associated with lower IVR and ORI scores, but a causative relationship remains to be demonstrated. A minimum viewing distance of 25 m is recommended for breeding Wandering Albatrosses.
Marienne S. de VilliersEmail: Fax: +27-21-6503434
John CooperEmail:
Peter G. RyanEmail:
  相似文献   

6.
   Soil conservation is widely regarded a critical component of sustainable livelihood strategies for the hillsides of Honduras. However, neoliberal polices have reduced economic incentives for agricultural intensification. Recent studies indicate off-farm work opportunities address poverty in a way conservation and development efforts do not. Yet off-farm work may discourage poor farmers from practicing soil conservation. A middle ground is needed. This study indicates micro-credit can substitute for off-farm work and encourage soil conservation practice. Many regions throughout Honduras have had extensive contact with soil conservation programs and would benefit more from credit services than redundant technological extension.
Christina H. GladwinEmail:
  相似文献   

7.
8.
This paper tries to explain how individuals manage adaptive individual choice (i.e., the decision to acquire a fitter than average behavior or idea rapidly and tractably) in cultural evolution, despite the fact that acquiring fitness information is very difficult. I argue that the means of solving this problem suggested in the cultural evolution literature largely are various types of decision rules employing representations of fitness correlated properties or states of affairs. I argue that the problem of adaptive individual choice is best solved where some of these learning rule representations are socially transmitted and some are biologically transmitted.
Catherine DriscollEmail:
  相似文献   

9.
A key point in the analysis of dynamical models of biological systems is to handle systems of relatively high dimensions. In the present paper we propose a method to hierarchically organize a certain type of piecewise affine (PWA) differential systems. This specific class of systems has been extensively studied for the past few years, as it provides a good framework to model gene regulatory networks. The method, shown on several examples, allows a qualitative analysis of the asymptotic behavior of a PWA system, decomposing it into several smaller subsystems. This technique, based on the well-known strongly connected components decomposition, is not new. However, its adaptation to the non-smooth PWA differential equations turns out to be quite relevant because of the strong discrete structure underlying these equations. Its biological relevance is shown on a 7-dimensional PWA system modeling the gene network responsible for the carbon starvation response in Escherichia coli.
Laurent Tournier (Corresponding author)Email:
Jean-Luc GouzéEmail:
  相似文献   

10.
Problems with studies, claims, and assumptions that have been made about the causes of fires in Indonesia's tropical moist forests are identified, and the kinds of concepts, methods, prioritizing, and data needed to resolve the problems are discussed. Separate sections are devoted to studying ignitions, studying fire susceptibility and fire behavior, and using the goal of causal explanation to guide interdisciplinary research.
Andrew P. VaydaEmail:
  相似文献   

11.
We develop a formal framework for the optimal allocation of limited resources that includes and clarifies the interplay between individual optimization and the resulting effects at the population level. As an example, in regard to the evolution of sexual recombination, the paradox of the twofold cost of sex is avoided by distinguishing between the evolution of recombination and the subsequent emergence and stability of different mating types as a result of individual optimization within a population that benefits from recombination.
John PepperEmail:
  相似文献   

12.
This paper introduces a threshold policy with hysteresis (TPH) for the control of one-predator one-prey models. The models studied are the Lotka–Volterra and Rosenzweig–MacArthur two species density-dependent predator–prey models and the Arditi–Ginzburg nondimensional ratio-dependent model. The proposed policy (TPH) changes the dynamics of the system in such a way that a bounded oscillation is achieved confined to a region that does not allow extinction of either species. The policy can be designed by a suitable choice of so called virtual equilibrium points in a simple and intuitive manner.
Amit Bhaya (Corresponding author)Email:
  相似文献   

13.
Many marine protected areas (MPAs), particularly in developing countries, have failed because of a lack of enforcement and monitoring due to limited public funds for conservation. Private investment and management in MPAs offers a potential solution, and has been applied with initial positive results at the Sugud Islands Marine Conservation Area (SIMCA) in Sabah, Malaysia. Conservation fees charged to visitors to Lankayan Island Dive Resort within the SIMCA have generated a sustainable source of financing to meet the majority of management costs for the conservation area, which is separately managed by a private organization called Reef Guardian. The availability of adequate funds has enabled Reef Guardian to invest in personnel training and surveillance technology to enforce the rules and regulations of the conservation area. In collaboration with government enforcement agencies, Reef Guardian has reduced threats such as illegal fishing and turtle egg poaching. As a result, there is a comparatively high abundance of commercially important fish, and turtle nestings at Lankayan Island have increased. Private management can be effective in conserving biodiversity in MPAs, and may well succeed regionally in suitable locations.
Lydia C. L. TehEmail:
  相似文献   

14.
Resin producing agroforestry in the Krui area of Sumatra in Indonesia is presented as an environmentally friendly, income generating land-use system which contributes to both development and conservation objectives. We studied the change in household income portfolios in three communities in the Krui area. The studies revealed that in the period 1995–2004 agroforestry remained the main source of income. We predict, however, that due to declining resin productivity per hectare, and rising price and demand for timber, an increasing number of farmers will cut their mature agroforests in the near future. At the same time our data suggests that farmers will continue tree planting activities. In result old agroforests may vanish while new ones will be established.
Koen KustersEmail:
  相似文献   

15.
16.
The recent contribution by Jarmila Kukalová-Peck on Hennigian phylogenetics and hexapod limb evolution is critically evaluated.
Michael S. Engel (Corresponding author)Email:
  相似文献   

17.
Jablonka and Lamb's claim that evolutionary biology is undergoing a ‘revolution’ is queried. But the very concept of revolutionary change has uncertain application to a field organized in the manner of contemporary biology. The explanatory primacy of sequence properties is also discussed.
Peter Godfrey-SmithEmail:
  相似文献   

18.
Common Ground: Risk, Scarcity, and Shared Resources in Goan Agriculture   总被引:1,自引:1,他引:0  
In the Indian state of Goa, communally owned agricultural land has persisted through indigenous state rule, colonial occupation and postcolonial liberation. We show that in Goa, and indeed elsewhere in the world, communally owned land provides protection against scarcity, risk, and state revenue demands in wet rice agriculture. When wet rice agriculture is the primary agricultural activity, communally owned land is an effective way to utilize resources. These findings add to the literature that challenges the inevitability of the tragedy of commonly owned resources.
Paul AxelrodEmail:
  相似文献   

19.
To our knowledge, this paper is the first record/report of a juvenile light-coloured Weddell seal (Leptonychotes weddellii) at Cape Shirreff, Livingston Island in January 1998, determining that it was an albino individual. Based on available literature, three cases of albino seals have been reported exclusively for Harbour seal pups, and no albino has been reported for Antarctic pagophilic true seals. Therefore, this is the first confirmed case of albinism in Antarctic pagophilic true seals species, indicating that this phenomenon is indeed of a rare occurrence.
Daniel TorresEmail:
  相似文献   

20.
Overintensification and subsidies have long made American commodity farmers the enemy of conservationists. Yet, environmental conditions are improving in the Mississippi Delta where farmer-based groups, water management districts and conservation organizations have improved environmental quality and redefined the role of agriculture in environmental preservation. This work is all the more remarkable given the region’s deeply conservative politics that discourage regulation. This paper examines this mainstreaming of environmental values in light of debates on the role of the state in fostering environmental subjectivities. Following cultural examinations of the state, we caution that the presence or retreat of the state is insufficient to understanding environmental subjectivities. Instead, an ethnographic focus is necessary to identify connections between the state and particular human-environment relations. In the Delta, this focus shows that local environmentalism is consonant with a politics of unsustainability, one that simultaneously advances radical ecological change and defense of the region’s social hierarchies.
Eleanor E. ShoremanEmail:
  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号