Departamento de Zoologia, Laboratório de Evolução de Mamíferos, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Departamento de Biologia, Setor de Zoologia Comparada, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil.
Am J Primatol. 2021 Feb;83(2):e23226. doi: 10.1002/ajp.23226. Epub 2021 Jan 25.
The Saguinus mystax group traditionally includes three species, S. mystax, S. labiatus, and S. imperator. The additional inclusion of S. inustus is argued on molecular grounds, which have an important impact on our comprehension of the phenotypical evolution and biogeography of the group. Here, we investigate the evolutionary events leading to the diversification of the S. mystax group, integrating phylogenetic, temporal, and geographic information with the current knowledge of the Amazonian paleogeographical history. The examination of 208 specimens of Saguinus resulted in 25 morphological characters, of which 13 were used for the first time in a phylogenetic analysis of the genus. Morphological characters were also combined with molecular data and analyzed using Bayesian and Maximum Likelihood methods. Trees resulting from morphological and combined data recovered a monophyletic S. mystax group, including S. inustus, whose inclusion was supported by two morphological synapomorphies. Molecular based age estimates place the origin of Saguinus in the middle Miocene (17.4-13 million years ago [mya]), whereas the S. mystax group originated in an interval between 12 and 6 mya. Our results also suggest that the ancestral area of Saguinus was western Amazon, from where they dispersed to their current distribution after the end of the Pebas lakes system. The diversification events in the S. mystax group are related to the Pliocene development of the modern Amazon river network associated to the uplift of Fitzcarrald Arch.
传统上，卷尾猴神秘种组包括三个物种，即神秘卷尾猴、白唇卷尾猴和皇帝卷尾猴。根据分子证据，额外包括了无毛卷尾猴。这一发现对我们理解该种群的表型进化和生物地理学具有重要影响。在这里，我们通过整合系统发育、时间和地理信息，以及对亚马逊古地理历史的现有认识，研究了导致神秘种组多样化的进化事件。对 208 个卷尾猴标本的研究得出了 25 个形态特征，其中 13 个特征首次用于该属的系统发育分析。形态特征还与分子数据相结合，并使用贝叶斯和最大似然方法进行了分析。基于形态和组合数据的树恢复了一个单系的神秘种组，包括无毛卷尾猴，其包含得到了两个形态学synapomorphies 的支持。基于分子的年龄估计表明，卷尾猴起源于中新世中期（1740-1300 万年前），而神秘种组起源于 1200-600 万年前。我们的研究结果还表明，卷尾猴的祖先区域是亚马逊西部，它们在皮贝斯湖系统结束后从那里扩散到现在的分布区域。神秘种组的多样化事件与现代亚马逊河网的上新世发展以及菲茨罗伊拱的隆起有关。
