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arXiv 0901.0976q-bio.PE
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食物网〈动〉<动>度分布的简单MaxEnt模型

Simple MaxEnt Models for Food Web Degree Distributions

Richard J. Williams

摘要:

度分布已被广泛用于表征包括食物网在内的生物网络,并在最近的食物网〈动〉<动>结构模型中起着至关重要的作用。虽然食物网度分布已被建议遵循各种功能形式,迄今为止,还没有这些形式的机械或统计解释。在这里,我介绍的食物网的度分布模型的基础上的最大熵(MaxEnt)的原则,由物种的数量,链接的数量和数量的顶部或底部的物种。MaxEnt预测相比,观察到的分布在51个食物网。在95%的置信水平下,23个食物网(45%)和35个食物网(69%)的消费者和资源数量分布与MaxEnt分布没有显著差异。虽然生态位模型的网络资源分布很好地描述了MaxEnt模型,消费者分布更窄的分布比MaxEnt模型预测。这些发现提供了一个新的空模型在食物网中的最可几度分布。有一个适当的零假设的地方允许信息研究的偏差,例如,这些结果表明,有相对较小的压力,有利于通才与专家的消费策略,但有更多的压力,推动消费者分布远离MaxEnt形式。鉴于当前食物网〈动〉<动>数据的方法学特性,对此类偏离的进一步研究需要考虑生物驱动因素和方法学偏倚。

英文摘要:

Degree distributions have been widely used to characterize biological networks including food webs, and play a vital role in recent models of food web structure. While food webs degree distributions have been suggested to follow various functional forms, to date there has been no mechanistic or statistical explanation for these forms. Here I introduce models for the degree distributions of food webs based on the principle of maximum entropy (MaxEnt) constrained by the number of species, number of links and the number of top or basal species. The MaxEnt predictions are compared to observed distributions in 51 food webs. The distributions of the number of consumers and resources in 23 (45%) and 35 (69%) of the food webs respectively are not significantly different at a 95% confidence level from the MaxEnt distribution. While the resource distributions of niche model webs are well-described by the MaxEnt model, the consumer distributions are more narrowly distributed than predicted by the MaxEnt model. These findings offer a new null model for the most probable degree distributions in food webs. Having an appropriate null hypothesis in place allows informative study of the deviations from it; for example these results suggest that there is relatively little pressure favoring generalist versus specialist consumption strategies but that there is more pressure driving the consumer distribution away from the MaxEnt form. Given the methodological idiosyncrasies of current food web data, further study of such deviations will need to consider both biological drivers and methodological bias.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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