Department of Biological Sciences, University of Idaho, Moscow, Idaho, USA.
Mol Ecol Resour. 2024 Apr;24(3):e13938. doi: 10.1111/1755-0998.13938. Epub 2024 Feb 26.
Species delimitation is a contentious topic. The genomics revolution initially brought hope that identifying and classifying species would be easier through better methods and more data, but genomics has also brought complexity and controversy to delimitation. One solution can be to collect a larger sample of individuals at a finer geographic scale. But what if taxa are rare and collecting more samples is difficult or detrimental to the organisms at hand? In this issue of Molecular Ecology Resources, Opatova et al. (2023) tackle the ambiguity of species delimitation in rare and endangered trapdoor spiders (genus Cyclocosmia). The authors propose a framework for delimiting species when samples are hard to come by, such as in these rare and cryptic spiders. The authors combine extensive genomic sampling with statistical approaches that consider both the genetic distinctiveness of each population of spiders and how much gene flow occurs between these populations. Their proposed taxonomy balances two opposing signals, structure and gene flow, to count eight lineages of Cyclocosmia, and to point the way for future taxonomic studies of the rare or difficult to obtain.
物种划分是一个有争议的话题。基因组学革命最初带来了希望，即通过更好的方法和更多的数据，识别和分类物种将变得更加容易，但基因组学也给划分带来了复杂性和争议。一种解决方案可以是在更精细的地理尺度上收集更多个体的样本。但是，如果分类单元很少，并且收集更多样本很困难或对现有生物有害呢？在本期《分子生态学资源》杂志中，Opatova 等人（2023 年）解决了稀有和濒危活板门蜘蛛（Cyclocosmia 属）物种划分的模糊性问题。作者提出了一个在难以获得样本时划定物种的框架，例如在这些稀有和隐匿的蜘蛛中。作者结合了广泛的基因组采样和统计方法，这些方法同时考虑了每个蜘蛛种群的遗传独特性以及这些种群之间发生的基因流动程度。他们提出的分类法平衡了结构和基因流动这两个相反的信号，将 Cyclocosmia 分为 8 个谱系，并为未来对稀有或难以获得的物种的分类学研究指明了方向。
