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Journal Article Modelling Malaria as a Complex Adaptive System(1997) Janssen, Marco A.; Martens, W.J.M."As the resistance of the malaria parasite to antimalarial drugs continues to increase, as does that of the malarial mosquito to insecticides, the efficacy of efforts to control malaria in many tropical countries is diminishing. This trend, together with the projected consequences of climate change, may prove to exacerbate substantially the significance of malaria in the coming decades. "In this article we introduce the use of an evolutionary modeling approach to simulate the adaptation of mosquitoes and parasites to the available pesticides and drugs. By coupling genetic algorithms with a dynamic malaria-epidemiological model, we derive a complex adaptive system capable of simulating adapting and evolving processes within both the mosquito and the parasite populations. "This approach is used to analyze malaria management strategies appropriate to regions of higher and lower degrees of endemicity. The results suggest that adequate use of insecticides and drugs may reduce the occurrence of malaria in regions of low endemicity, although increased efforts would be necessary in the event of a climate change. However, our model indicates that in regions of high endemicity the use of insecticides and drugs may lead to an increase in incidence due to enhanced resistance development. Projected climate change, on the other hand, may lead to a limited reduction of the occurrence of malaria due to the presence of a higher percentage of immune persons in the older age class."Journal Article The Battle of Perspectives: A Multi-Agent Model with Adaptive Responses to Climate Change(1998) Janssen, Marco A.; de Vries, Bert"To evaluate possible futures with regard to economy, energy and climate, a multi-agent modelling approach is used. Agents hold different perspectives on how the world functions (world view) and how it should be managed (management style) and this is implemented in a simple dynamic model of the economy-energy-climate system. Each perspective is supported by a proportion of the agents, but this proportion changes in response to observations about the real world. In this way the totality of agents learn from their observations. It is concluded that this approach is a good illustration of how adaptive behavior can be included in global change modelling. Some exploratory experiments are done to address the consequences of surprises."Journal Article Ecology, Ethics, and Advocacy(1997) Peterson, Garry D.; Pope, Shealagh E.; De Leo, Giulio Alessandro; Janssen, Marco A.; Malcolm, Jay R.; Parody, Jennifer M.; Hood, Greg; North, Malcolm"Anthropogenic global change is radically altering climate, mineral cycles, land cover, and biotic communities (Turner et al. 1993, Vitousek 1994). These changes ensure that everywhere on Earth is affected by human actions. In some areas, such as the center of large cities, human transformation is near absolute, whereas in other places, such as remote parks, human influence is felt chiefly through the alteration of global cycles. However, no place is free from multiple, confounded human impacts. Consequently, ecological studies, whether they attend to or not, are partially studying the impact of anthropogenic change. "Ecologists cannot ignore these changes. First, ignoring these changes will produce flawed science; if ecologists ignore anthropogenic influences, they will probably attribute change to the wrong processes. Second, and perhaps more important, if ecologists want to guide or 'engineer' the human transformation of the earth to reduce unintended consequences, they need to understand how ecosystems organize and function in response to a huge variety of anthropogenic alterations. "Engineering ecological systems is dangerous. Nature is neither predictable nor inert; rather it is evolutionary and self-modifying. History, evolution, and variation are all central to ecology, but foreign to the 'memory-less,' repeatable, and variation-minimizing methods of traditional engineering. "Ecologists cannot hide behind 'pure' science and divorce themselves from the dangerous application of ecology. Whether ecologists like it or not, managers, policy makers, and the general public use ecological theory, or at least their understanding of ecological theory, to make decisions. To promote 'reflective' management and sound science, ecologists need to study, criticize, and inform the human transformation of nature."