Infraspecific taxa (subspecies, races and varieties) are often seen as real entities in nature and recognized as biologically meaningful groups. But because infraspecific taxa by definition are subdivisions of species, their status depends entirely on the status of ‘their’ species. This makes the status of infraspecific taxa crucially dependent on the way species are considered and thus on the various species concepts that have been advanced as answers to the ‘species problem’. Accordingly, there is a profound lack of clarity regarding the following questions. What are infraspecific taxa? What is their biological meaning? Are they real entities or merely instrumental units? When should an infraspecific group be ranked and named as an infraspecific taxon? In this paper, we aim to contribute to greater clarity about these issues by examining which types of infraspecific groups are biologically meaningful in light of the main results from the species debate.

中文翻译：

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低于物种水平的分类：种下群何时具有生物学意义？

种下分类群（亚种、种族和变种）通常被视为自然界中的真实实体，并被认为是具有生物学意义的群体。但是，因为根据定义，种下分类群是物种的细分，它们的地位完全取决于“他们的”物种的地位。这使得种下分类群的地位在很大程度上取决于考虑物种的方式，因此取决于作为“物种问题”的答案而提出的各种物种概念。因此，以下问题严重缺乏明确性。什么是种下分类群？它们的生物学意义是什么？它们是真实的实体还是仅仅是工具单位？何时应将种下群列为种下分类单元并将其命名为种下分类单元？在本文中，