Previous studies of butterfly diversification in the Neotropics have focused on Amazonia and the tropical Andes, while southern regions of the continent have received little attention. To address the gap in knowledge about the Lepidoptera of temperate South America, we analysed over 3000 specimens representing nearly 500 species from Argentina for a segment of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Representing 42% of the country's butterfly fauna, collections targeted species from the Atlantic and Andean forests, and biodiversity hotspots that were previously connected but are now isolated. We assessed COI effectiveness for species discrimination and identification and how its performance was affected by geographic distances and taxon coverage. COI data also allowed to study patterns of genetic variation across Argentina, particularly between populations in the Atlantic and Andean forests. Our results show that COI discriminates species well, but that identification success is reduced on average by ~20% as spatial and taxonomic coverage rises. We also found that levels of genetic variation are associated with species' spatial distribution type, a pattern which might reflect differences in their dispersal and colonization abilities. In particular, intraspecific distance between populations in the Atlantic and Andean forests was significantly higher in species with disjunct distributions than in those with a continuous range. All splits between lineages in these forests dated to the Pleistocene, but divergence dates varied considerably, suggesting that historical connections between the Atlantic and Andean forests have differentially affected their shared butterfly fauna. Our study supports the fact that large-scale assessments of mitochondrial DNA variation are a powerful tool for evolutionary studies.

中文翻译：

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新热带蝴蝶的遗传变异与采样规模、物种分布和历史森林动态有关

以前对新热带地区蝴蝶多样化的研究主要集中在亚马逊和热带安第斯山脉，而该大陆的南部地区很少受到关注。为了解决有关南美洲温带鳞翅目昆虫的知识空白，我们分析了代表来自阿根廷的近 500 个物种的 3000 多个标本的线粒体细胞色素c片段氧化酶亚基 I (COI) 基因。代表该国 42% 的蝴蝶动物群，收集目标来自大西洋和安第斯森林的物种，以及以前相互联系但现在孤立的生物多样性热点。我们评估了 COI 对物种歧视和识别的有效性以及其性能如何受地理距离和分类单元覆盖率的影响。COI 数据还允许研究整个阿根廷的遗传变异模式，特别是大西洋和安第斯森林中种群之间的遗传变异模式。我们的结果表明，COI 可以很好地区分物种，但随着空间和分类学覆盖率的增加，识别成功率平均降低了约 20%。我们还发现遗传变异的水平与物种的空间分布类型有关，一种模式，可能反映了他们的传播和殖民能力的差异。特别是，大西洋和安第斯森林中种群之间的种内距离在具有分离分布的物种中显着高于具有连续分布的物种。这些森林中谱系之间的所有分裂都可以追溯到更新世，但分歧日期差异很大，这表明大西洋和安第斯森林之间的历史联系对它们共享的蝴蝶动物群产生了不同的影响。我们的研究支持这样一个事实，即对线粒体 DNA 变异的大规模评估是进化研究的有力工具。大西洋和安第斯森林种群之间的种内距离在具有分离分布的物种中显着高于具有连续分布的物种。这些森林中谱系之间的所有分裂都可以追溯到更新世，但分歧日期差异很大，这表明大西洋和安第斯森林之间的历史联系对它们共享的蝴蝶动物群产生了不同的影响。我们的研究支持这样一个事实，即对线粒体 DNA 变异的大规模评估是进化研究的有力工具。大西洋和安第斯森林种群之间的种内距离在具有分离分布的物种中显着高于具有连续分布的物种。这些森林中谱系之间的所有分裂都可以追溯到更新世，但分歧日期差异很大，这表明大西洋和安第斯森林之间的历史联系对它们共享的蝴蝶动物群产生了不同的影响。我们的研究支持这样一个事实，即对线粒体 DNA 变异的大规模评估是进化研究的有力工具。