Dipartimento di Fisica G. Galilei and CNISM, INFN, Università di Padova, Via Marzolo 8, 35131 Padova, Italy.
Phys Rev Lett. 2012 Jul 20;109(3):038102. doi: 10.1103/PhysRevLett.109.038102.
Spontaneous symmetry breaking plays a fundamental role in many areas of condensed matter and particle physics. A fundamental problem in ecology is the elucidation of the mechanisms responsible for biodiversity and stability. Neutral theory, which makes the simplifying assumption that all individuals (such as trees in a tropical forest)--regardless of the species they belong to--have the same prospect of reproduction, death, etc., yields gross patterns that are in accord with empirical data. We explore the possibility of birth and death rates that depend on the population density of species, treating the dynamics in a species-symmetric manner. We demonstrate that dynamical evolution can lead to a stationary state characterized simultaneously by both biodiversity and spontaneously broken neutral symmetry.
自发对称破缺在凝聚态物理和粒子物理的许多领域中起着基本作用。生态学中的一个基本问题是阐明负责生物多样性和稳定性的机制。中性理论做出了简化的假设，即所有个体（例如热带雨林中的树木）——无论它们属于哪个物种——都具有相同的繁殖、死亡等前景，从而产生与经验数据相符的总模式。我们探讨了依赖于物种种群密度的出生率和死亡率的可能性，以物种对称的方式处理动力学。我们证明，动力学演化可以导致同时具有生物多样性和自发破缺中性对称性的稳定状态。
