Recent scientific and technological advances have improved and streamlined our ability to recognise and describe fungal species. Detailed comparative genomics studies have also expanded our understanding of species boundaries. Against this background, we explore the nature of fungal species and consider how this impacts our understanding of their genetics and evolution. The current body of evidence suggests that fungal species are unique evolutionary units that are separated from one another by boundaries that are “porous” under certain conditions (“semipermeable” in analogy to the differential permeability of membranes). Overall, the penetrability of these boundaries depends on the relatedness between donor and recipient species, the spatial proximity of related species to one another during their evolution, and the evolutionary potential associated with the breach of a boundary. Furthermore, the semipermeable nature of species boundaries fundamentally affects the population genetics of a species, with potentially profound effects on its overall evolution and biology. This also influences the methodologies used in taxonomy, because some species appear capable of maintaining their genetic isolation despite extensive penetrability of their boundaries. Most analytical procedures are also not able to distinguish the signals of species boundary permeability from those associated with incomplete lineage sorting or intraspecific diversity. Collectively, these issues greatly complicate how we study and name fungi. An awareness of the nature of species, their boundaries and the biological and genomic signatures of boundary breaches, will enhance our ability to identify them and, perhaps more importantly, to develop realistic strategies to manage and manipulate their growth and distribution.

最近的科学和技术进步提高并简化了我们识别和描述真菌物种的能力。详细的比较基因组学研究也扩大了我们对物种边界的理解。在这种背景下，我们探索了真菌物种的性质，并考虑了这如何影响我们对它们的遗传和进化的理解。当前的证据表明，真菌物种是独特的进化单位，在某些条件下被“多孔”的边界彼此隔开（类似于膜的差渗透性，“半渗透性”）。总体而言，这些边界的可穿透性取决于捐赠者和接受者物种之间的关联性，相关物种在进化过程中彼此之间的空间接近性，以及与突破边界有关的进化潜力。此外，物种边界的半透性本质从根本上影响一个物种的种群遗传学，对其总体进化和生物学产生潜在的深远影响。这也影响了分类学中使用的方法，因为尽管某些物种的边​​界具有广泛的穿透性，但它们似乎仍能够保持其遗传隔离。大多数分析程序也无法将物种边界渗透性信号与与不完整谱系分选或种内多样性相关的信号区分开。总的来说，这些问题使我们如何研究和命名真菌变得更加复杂。了解物种的性质，其边界以及边界突破的生物学和基因组学特征，