Abstract：
Marine microbial communities are extremely complex and diverse. The number of locally coexisting species often vastly exceeds the number of identifiable niches, and taxonomic composition often appears decoupled from local environmental conditions. This is contrary to the view that environmental conditions should select for a few locally well-adapted species. Here we use an individual-based eco-evolutionary model to show that virtually unlimited taxonomic diversity can be supported in highly evolving assemblages, even in the absence of niche separation. With a steady stream of heritable changes to phenotype, competitive exclusion may be weakened, allowing sustained coexistence of nearly neutral phenotypes with highly divergent lineages. This behaviour is robust even to abrupt environmental perturbations that might be expected to cause strong selection pressure and an associated loss of diversity. We, therefore, suggest that rapid evolution and individual-level variability are key drivers of species coexistence and maintenance of microbial biodiversity.
摘要：
海洋微生物群落极其复杂多样。本地共存物种的数量通常大大超过可识别的生态位的数量，分类组成通常与当地环境条件脱钩。这与环境条件应该为一些当地适应良好的物种选择的观点相反。在这里，我们使用基于个体的生态进化模型来表明，高度进化的组合可以支持几乎无限的分类多样性，即使在没有生态位分离的情况下。随着表型的遗传变化源源不断，竞争排斥可能会被削弱，允许几乎中性的表型与高度不同的谱系持续共存。即使对于可能导致强烈选择压力和相关多样性损失的突然环境扰动，这种行为也是稳健的。我们,因此,表明快速进化和个体水平的变异性是物种共存和维持微生物生物多样性的关键驱动因素。
