Our planet teems with microorganisms that often present a skewed abundance distribution in a local community, with relatively few dominant species coexisting alongside a high number of rare species. Recent studies have demonstrated that these rare taxa serve as limitless reservoirs of genetic diversity, and perform disproportionate types of functions despite their low abundances. However, relatively little is known about the mechanisms controlling rarity and the processes promoting the development of the rare biosphere. Here, we propose the use of multivariate cut-offs to estimate rare species and phylogenetic null models applied to predefined rare taxa to disentangle the relative influences of ecoevolutionary processes mediating the assembly of the rare biosphere. Importantly, the identification of the factors controlling rare species assemblages is critical for understanding the types of rarity, how the rare biosphere is established, and how rare microorganisms fluctuate over spatiotemporal scales, thus enabling prospective predictions of ecosystem responses.

我们的星球上充斥着微生物，这些微生物通常在当地社区中呈现出不均衡的丰度分布，相对少有的优势物种与大量的稀有物种并存。最近的研究表明，这些稀有的类群可作为遗传多样性的无限库，尽管它们的丰度很低，但它们执行的功能却不成比例。但是，关于控制稀有性的机制和促进稀有生物圈发展的过程知之甚少。在这里，我们建议使用多元临界值来估计稀有物种，并将系统发育空模型应用于预定义的稀有分类群，以消除介导稀有生物圈组装的生态进化过程的相对影响。重要的，