SummaryWe combined tools of phylogeography, population genetics and biogeographical interpretation to analyse a group of phylogenetically independent lineages (animals and plants) that coexist within the same geographical region, yet under markedly different environments, in order to identify generalized barriers for gene flow. We tested the hypothesis that major geographic features have produced a concordant genetic structure in phylogenetically independent lineages. A rigorous bibliographic search was performed, selecting available molecular information from six taxa occupying distinct southern biomes of South America: Yungas, Prepuna, Puna and northern Monte. We estimated within-population genetic diversity, the genetic structure and haplotype phylogenies to assemble distribution maps of genetic barriers for each species. We found a strong association between genetic variation and latitudinal distribution of populations. We detected a major barrier for six taxa at 27°S latitude and a second one for a group of three species at 25–26°S. Two alternative non-exclusive hypotheses – geology and/or climate – explain concordant genetic barriers in divergent lineages. We suggest that the term ‘biogeographically significant units’ portrays a group of populations of phylogenetically unrelated taxa that inhabit the same geographic region that have been similarly impacted by major physical events, which can be used to identify priority areas in landscape conservation.

中文翻译：

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保护中具有重要生物地理意义的单位：保护生态和进化过程的新综合概念

总结我们结合系统地理学、种群遗传学和生物地理学解释工具来分析在同一地理区域内共存但在显着不同环境下的一组系统发育独立谱系（动物和植物），以确定基因流动的普遍障碍。我们检验了主要地理特征在系统发育独立的谱系中产生了一致的遗传结构的假设。进行了严格的书目搜索，从占据南美洲不同南部生物群落的六个分类群中选择可用的分子信息：Yungas、Prepuna、Puna 和北蒙特。我们估计了种群内的遗传多样性、遗传结构和单倍型系统发育，以组装每个物种的遗传屏障分布图。我们发现遗传变异与种群的纬度分布之间存在很强的关联。我们在 27°S 纬度检测到六个分类群的主要障碍，在 25-26°S 检测到一组三个物种的第二个障碍。两个替代的非排他性假设——地质学和/或气候——解释了不同谱系中一致的遗传障碍。我们建议，“具有重要生物地理意义的单位”一词描述了居住在同一地理区域的一组系统发育不相关的分类群，这些分类群同样受到重大物理事件的影响，可用于确定景观保护的优先区域。两个替代的非排他性假设——地质学和/或气候——解释了不同谱系中一致的遗传障碍。我们建议，“具有重要生物地理意义的单位”一词描述了居住在同一地理区域的一组系统发育不相关的分类群，这些分类群同样受到重大物理事件的影响，可用于确定景观保护的优先区域。两个替代的非排他性假设——地质学和/或气候——解释了不同谱系中一致的遗传障碍。我们建议，“具有重要生物地理意义的单位”一词描述了居住在同一地理区域的一组系统发育不相关的分类群，这些分类群同样受到重大物理事件的影响，可用于确定景观保护的优先区域。