Pastorini J, Forstner M R, Martin R D, Melnick D J
Anthropologisches Institut, Universität Zürich-Irchel, Switzerland.
J Mol Evol. 1998 Jul;47(1):32-41. doi: 10.1007/pl00006360.
The New World monkeys are divided into two main groups, Callitrichidae and Cebidae. Callimico goeldii shares traits with both the Cebidae and the Callitrichidae. Recent morphological phyletic studies generally place Callimico as the most basal member of the Callitrichidae. In contrast, genetic studies (immunological, restriction fragment, and sequence data) have consistently placed Callimico somewhere within the Callitrichidae, not basal to this clade. A DNA sequence data set from the terminal 236 codons of the mitochondrial ND4 gene and the tRNA(His), tRNA(Ser), and tRNA(Leu) genes was generated to clarify the position of Callimico. The sequences of 887 base pairs were analyzed by maximum-parsimony, neighbor-joining, and maximum-likelihood methods. The results of these various methods are generally congruent and place Callimico within the Callitrichidae between the marmosets (Callithrix and Cebuella) and the tamarins (Saguinus and Leontopithecus). Combined analyses of all suitable nuclear and mitochondrial gene sequences confirm the position of Callimico between the marmosets and the tamarins. As available molecular evidence indicates that Callimico is more closely related to the marmosets than to the tamarins, a reconsideration of the morphological evidence in light of the consensus tree from DNA sequence analyses is warranted. The marmosets and tamarins share four morphological characters (loss of the third molar, loss of the hypocone, reduced body size, reproductive twinning). Dwarfism may have evolved repeatedly among the Callitrichidae. It is well-known that the loss of a character can occur many times independently. The reproduction of marmosets and tamarins is extremely specialized and it is difficult to imagine that this complex and unique twinning system evolved separately in marmosets and tamarins. However, it is possible that a secondary reversal to single offspring took place in Callimico.
新大陆猴分为两个主要类群，即狨科和卷尾猴科。黄头狨与卷尾猴科和狨科都有共同特征。最近的形态系统发育研究通常将黄头狨置于狨科最基部的成员位置。相比之下，遗传学研究（免疫学、限制性片段和序列数据）一直将黄头狨置于狨科内部的某个位置，而非该分支的基部。生成了一个来自线粒体ND4基因末端236个密码子以及tRNA(His)、tRNA(Ser)和tRNA(Leu)基因的DNA序列数据集，以阐明黄头狨的位置。通过最大简约法、邻接法和最大似然法对887个碱基对的序列进行了分析。这些不同方法的结果总体上是一致的，并将黄头狨置于狨科内部，介于狨属（Callithrix和Cebuella）和绢毛猴属（Saguinus和狮面狨属Leontopithecus）之间。对所有合适的核基因和线粒体基因序列的综合分析证实了黄头狨在狨属和绢毛猴属之间的位置。由于现有的分子证据表明黄头狨与狨属的关系比与绢毛猴属的关系更密切，因此有必要根据DNA序列分析的一致树重新审视形态学证据。狨属和绢毛猴属共有四个形态特征（第三磨牙缺失、次尖缺失、体型缩小、孪生繁殖）。侏儒症可能在狨科中多次独立进化。众所周知，一个特征的丧失可能多次独立发生。狨属和绢毛猴属的繁殖极其特殊，很难想象这种复杂而独特的孪生系统在狨属和绢毛猴属中是分别独立进化的。然而，黄头狨有可能发生了向单胎繁殖的二次逆转。
