Mohlenhoff Kathryn A, Codding Brian F
Department of Anthropology, University of Utah.
Evol Anthropol. 2017 Sep;26(5):218-227. doi: 10.1002/evan.21534.
Humans modify their environments in ways that significantly transform the earth's ecosystems. Recent research suggests that such niche-constructing behaviors are not passive human responses to environmental variation, but instead should be seen as active and intentional management of the environment. Although such research is useful in highlighting the interactive dynamics between humans and their natural world, the niche-construction framework, as currently applied, fails to explain why people would decide to modify their environments in the first place. To help resolve this problem, we use a model of technological intensification to analyze the cost-benefit trade-offs associated with niche construction as a form of patch investment. We use this model to assess the costs and benefits of three paradigmatic cases of intentional niche construction in Western North America: the application of fire in acorn groves, the manufacture of fishing weirs, and the adoption of maize agriculture. Intensification models predict that investing in patch modification (niche construction) only provides a net benefit when the amount of resources needed crosses a critical threshold that makes the initial investment worthwhile. From this, it follows that low-cost investments, such as burning in oak groves, should be quite common, while more costly investments, such as maize agriculture, should be less common and depend on the alternatives available in the local environment. We examine how patterns of mobility, risk management, territoriality, and private property also co-evolve with the costs and benefits of niche construction. This approach illustrates that explaining niche-constructing behavior requires understanding the economic trade-offs involved in patch investment. Integrating concepts from niche construction and technological intensification models within a behavioral ecological framework provides insights into the coevolution and active feedback between adaptive behaviors and environmental change across human history.
人类以显著改变地球生态系统的方式改变其环境。最近的研究表明，这种生态位构建行为并非人类对环境变化的被动反应，而应被视为对环境的主动且有意的管理。尽管此类研究有助于凸显人类与其自然世界之间的互动动态，但目前应用的生态位构建框架未能解释人们最初为何会决定改变其环境。为帮助解决这一问题，我们使用技术强化模型来分析与作为一种斑块投资形式的生态位构建相关的成本效益权衡。我们用该模型评估北美西部三个典型的有意生态位构建案例的成本和效益：橡树林中用火、建造捕鱼堰以及采用玉米农业。强化模型预测，只有当所需资源量超过使初始投资变得值得的关键阈值时，对斑块改造（生态位构建）进行投资才会带来净收益。由此可见，低成本投资，如在橡树林中焚烧，应该相当普遍，而成本更高的投资，如玉米农业，应该不太常见且取决于当地环境中可用的替代方案。我们研究了流动性、风险管理、领地性和私有财产模式如何也与生态位构建的成本和效益共同演化。这种方法表明，解释生态位构建行为需要理解斑块投资中所涉及的经济权衡。将生态位构建和技术强化模型中的概念整合到行为生态框架内，能为人类历史上适应性行为与环境变化之间的共同演化和积极反馈提供见解。
