Defining Relictual Biodiversity: Conservation Units in Speckled Dace (Leuciscidae: Rhinichthys osculus) of the Greater Death Valley Ecosystem

The tips in the tree of life serve as foci for conservation and management, yet clear delimitations are masked by inherent variance at the species-population interface. Analyses using thousands of nuclear loci can potentially sort inconsistencies, yet standard categories applied to this parsing are themselves potentially conflicting and/or subjective [e.g., DPS (distinct population segments); DUs (Diagnosable Units-Canada); MUs (management units); SSP (subspecies); ESUs (Evolutionarily Significant Units); UIEUs (uniquely identified evolutionary units)]. One potential solution for consistent categorization is to create a comparative framework by accumulating statistical results from independent studies and evaluating congruence among data sets. Our study illustrates this approach in speckled dace (Leuciscidae: Rhinichthys osculus) endemic to two basins (Owens and Amargosa) in the Death Valley ecosystem. These fish persist in the Mojave Desert as isolated Plio-Pleistocene relicts and are ...生命之树的终端类群是保护与管理的核心着力点，但物种种群交界地带的内在变异，却掩盖了清晰的类群界定边界。借助数千个核基因座（nuclear loci）开展的分析，或可厘清各类不一致之处，但用于此类分类解析的标准范畴本身，亦可能存在冲突或主观性问题，例如：DPS（distinct population segments，独特种群片段）、DUs（Diagnosable Units-Canada，加拿大可鉴别单元）、MUs（management units，管理单元）、SSP（subspecies，亚种）、ESUs（Evolutionarily Significant Units，进化显著单元）、UIEUs（uniquely identified evolutionary units，唯一鉴定进化单元）。实现分类体系一致性的可行路径之一，是通过积累独立研究的统计结果、评估数据集间的一致性来构建比较分析框架。本研究以死亡谷生态系统中两个流域（欧文斯与阿马戈萨流域）的特有物种斑点雅罗鱼（Leuciscidae: Rhinichthys osculus）为对象，演示了该分析方法。这类鱼类作为孤立的上新世-更新世孑遗种群存续于莫哈韦沙漠，且……