Structural Characteristics of evolutionally developed phase spaces of ecosystems and proteins

生态系统和蛋白质进化发展的相空间的结构特征

基本信息

批准号：
13831006
负责人：
KIKUCHI Makoto
金额：
$ 2.24万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

In this project, we investigated structural characteristics of evolutionary developed phase spaces of ecosystems and proteins.For large-scale ecosystems, the following properties were clarified: The replicator equation systems with random interactions can have a stable coexistent state of many species, when the interactions are "antisymmetric". This result serves as the first counterexample for so-called "May's paradox" which is famous in the field of mathematical ecology. In the resultant stable ecosystem, we observe a emergence of a hierarchical food web structure. We propose a new simple model based of the replicator equation systems for studying dynamics of the biodiversity by taking into account the effects of extinction, invasion and mutation.As a basic research of dynamical systems which exhibit complex dynamics including ecosystems, we studied the intermittent transition behaviors between long-time persistent states. We found a new mechanism of emergence of chaotic metastability, and intermittent transition between these metastable states.For proteins, we focused our attention to the free-energy landscape of Kinesine, which is one of the motor proteins. We successfully sampled the thermally equilibrium ensemble in case of a simplified interaction parameters and studied its free-energy landscape near the native state for the first time. We found that the largest fluctuating mode is localized at the switch region. In other word, large-fluctuation of the switch region is embedded in the evolutionary developed free-energy landscape of Kinesine.

在本项目中，我们研究了生态系统和蛋白质的进化发展相空间的结构特征。对于大规模生态系统，阐明了以下性质：具有随机相互作用的复制方程系统可以具有多个物种的稳定共存状态，当相互作用是“反对称”的。这一结果成为数学生态学领域著名的所谓“梅氏悖论”的第一个反例。在由此产生的稳定生态系统中，我们观察到分层食物网结构的出现。我们提出了一种基于复制方程系统的新简单模型，通过考虑灭绝、入侵和突变的影响来研究生物多样性的动态。作为包括生态系统在内的复杂动态的动态系统的基础研究，我们研究了间歇性转变长期持续状态之间的行为。我们发现了一种出现混沌亚稳态以及这些亚稳态之间间歇性转变的新机制。对于蛋白质，我们将注意力集中在运动蛋白之一的运动蛋白的自由能景观上。我们成功地在简化相互作用参数的情况下对热平衡系综进行了采样，并首次研究了其接近自然状态的自由能景观。我们发现最大的波动模式位于开关区域。换句话说，开关区域的大波动嵌入在运动学的进化发展的自由能景观中。