Messinger Susanna M, Ostling Annette
University of Michigan, 2004 Kraus Natural Science Building, 830 North University, Ann Arbor, MI 48103, USA.
Theor Popul Biol. 2013 Nov;89:55-63. doi: 10.1016/j.tpb.2013.08.003. Epub 2013 Aug 22.
Predation interactions are an important element of ecological communities. Population spatial structure has been shown to influence predator evolution, resulting in the evolution of a reduced predator attack rate; however, the evolutionary role of traits governing predator and prey ecology is unknown. The evolutionary effect of spatial structure on a predator's attack rate has primarily been explored assuming a fixed metapopulation spatial structure, and understood in terms of group selection. But endogenously generated, emergent spatial structure is common in nature. Furthermore, the evolutionary influence of ecological traits may be mediated through the spatial self-structuring process. Drawing from theory on pathogens, the evolutionary effect of emergent spatial structure can be understood in terms of self-shading, where a voracious predator limits its long-term invasion potential by reducing local prey availability. Here we formalize the effects of self-shading for predators using spatial moment equations. Then, through simulations, we show that in a spatial context self-shading leads to relationships between predator-prey ecology and the predator's attack rate that are not expected in a non-spatial context. Some relationships are analogous to relationships already shown for host-pathogen interactions, but others represent new trait dimensions. Finally, since understanding the effects of ecology using existing self-shading theory requires simplifications of the emergent spatial structure that do not apply well here, we also develop metrics describing the complex spatial structure of the predator and prey populations to help us explain the evolutionary effect of predator and prey ecology in the context of self-shading. The identification of these metrics may provide a step towards expansion of the predictive domain of self-shading theory to more complex spatial dynamics.
捕食相互作用是生态群落的一个重要元素。种群空间结构已被证明会影响捕食者的进化，导致捕食者攻击率降低的进化；然而，控制捕食者和猎物生态的性状的进化作用尚不清楚。空间结构对捕食者攻击率的进化影响主要是在假设固定的集合种群空间结构的情况下进行探索的，并从群体选择的角度来理解。但内源性产生的、涌现的空间结构在自然界中很常见。此外，生态性状的进化影响可能通过空间自组织过程来介导。借鉴病原体理论，涌现空间结构的进化影响可以通过自我遮蔽来理解，即贪婪的捕食者通过减少当地猎物的可利用性来限制其长期入侵潜力。在这里，我们使用空间矩方程来形式化自我遮蔽对捕食者的影响。然后，通过模拟，我们表明在空间背景下，自我遮蔽会导致捕食者 - 猎物生态与捕食者攻击率之间的关系，而这些关系在非空间背景下是无法预期的。一些关系类似于已经在宿主 - 病原体相互作用中显示的关系，但其他关系代表了新的性状维度。最后，由于使用现有的自我遮蔽理论来理解生态效应需要对涌现的空间结构进行简化，而这种简化在此处并不适用，我们还开发了描述捕食者和猎物种群复杂空间结构的指标，以帮助我们在自我遮蔽的背景下解释捕食者和猎物生态的进化效应。这些指标的识别可能是朝着将自我遮蔽理论的预测领域扩展到更复杂的空间动态迈出的一步。
