Species‐level diversity and the underlying mechanisms that lead to the formation of new species, that is, speciation, have often been confounded with intraspecific diversity and population subdivision. The delineation between intraspecific and interspecific divergence processes has received much less attention than species delimitation. The ramifications of confounding speciation and population subdivision are that the term speciation has been used to describe many different biological divergence processes, rendering the results, or inferences, between studies incomparable. Phylogeographic studies have advanced our understanding of how spatial variation in the pattern of biodiversity can begin, become structured, and persist through time. Studies of species delimitation have further provided statistical and model‐based approaches to determine the phylogeographic entities that merit species status. However, without a proper understanding and delineation between the processes that generate and maintain intraspecific and interspecific diversity in a study system, the delimitation of species may still not be biologically and evolutionarily relevant. I argue that variation in the continuity of the divergence process among biological systems could be a key factor leading to the enduring contention in delineating divergence patterns, or species delimitation, meriting future comparative studies to help us better understand the nature of biological species.

中文翻译：

---

种群细分与物种形成不同吗？从系统发育地理学到物种界定。


物种层面的多样性和导致新物种形成的潜在机制，即物种形成，常常与种内多样性和种群细分相混淆。种内和种间分化过程之间的划分比物种划分受到的关注要少得多。混淆物种形成和种群细分的后果是，术语“物种形成”已被用来描述许多不同的生物分化过程，从而使研究之间的结果或推论变得不可比较。系统发育地理学研究增进了我们对生物多样性模式的空间变异如何开始、变得结构化并随着时间的推移持续存在的理解。物种界定研究进一步提供了基于统计和模型的方法来确定值得物种地位的系统发育地理实体。然而，如果没有对研究系统中产生和维持种内和种间多样性的过程进行适当的理解和描述，物种的界定可能仍然在生物学和进化上不相关。我认为，生物系统之间分化过程连续性的变化可能是导致划定分化模式或物种划界方面持久争论的关键因素，值得未来的比较研究以帮助我们更好地了解生物物种的本质。