Di-Nizo Camilla B, Suárez-Villota Elkin Y, Silva Maria José J
Laboratório de Ecologia e Evolução, Instituto Butantan, São Paulo, São Paulo, Brazil.
Leibniz Institute for the Analysis of Biodiversity Change, Zoological Research Museum A. Koenig, Bonn, Germany.
PeerJ. 2022 Apr 22;10:e13011. doi: 10.7717/peerj.13011. eCollection 2022.
is a genus of the tribe Oryzomyini with eight species currently recognized, and a controversial taxonomy. These species are mainly distributed in the South America dry diagonal, but some species extend into Atlantic Forest, reaching the coastal sandy plains known as Restingas. This study aimed to address species limits and patterns of diversification of species. For this purpose, we performed cytogenetic and molecular analyses (phylogeny, coalescent species delimitation, barcoding, and divergence times estimation) using multiple mitochondrial and nuclear markers on a comprehensive sampling, representing all nominal taxa reported so far. Chromosomal information was a robust marker recognizing eight species. Reciprocal monophyly was recovered for all the species, except for . These results together with coalescent analyses recovered eight species as the most congruent species delimitation scenario for the genus (mean C : 0.72). Divergence time estimates revealed that ' diversification occurred about 1.32 million years ago (Mya) during the Pleistocene. Although our results conservatively support the eight species described so far, different lines of evidence suggest that and could potentially be species-complexes. We discussed this scenario in the light of multiple evolutionary processes within and between species and populations, since comprises a species group with recent diversification affected by Pleistocene climatic changes and by the complex biogeographic history of South America dry diagonal. This work supports that the diversity of is underestimated and reiterates that interdisciplinary approaches are mandatory to identify small rodent species properly, and to unhide cryptic species.
是稻鼠族的一个属，目前已确认有八个物种，其分类存在争议。这些物种主要分布在南美洲的干燥对角线地区，但有些物种延伸至大西洋森林，到达被称为滨海沙原的沿海沙质平原。本研究旨在解决该属物种的界限及多样化模式问题。为此，我们使用多个线粒体和核标记，对全面采样进行了细胞遗传学和分子分析（系统发育、溯祖物种界定、条形码和分歧时间估计），采样代表了迄今为止报道的所有名义分类单元。染色体信息是识别八个物种的有力标记。除了[具体物种]外，所有物种均恢复为相互单系。这些结果与溯祖分析一起，确定八个物种是该属最一致的物种界定方案（平均C值：0.72）。分歧时间估计表明，[属名]的多样化发生在更新世约132万年前。尽管我们的结果保守地支持了迄今为止描述的八个物种，但不同的证据表明[具体物种1]和[具体物种2]可能潜在地是物种复合体。鉴于物种和种群内部及之间的多种进化过程，我们讨论了这种情况，因为[属名]包括一个受更新世气候变化和南美洲干燥对角线复杂生物地理历史影响而近期多样化的物种群。这项工作支持[属名]的多样性被低估，并重申跨学科方法对于正确识别小型啮齿动物物种和揭示隐存物种是必不可少的。
