Systematics of Enigmatic Canids: A Phylogenetic Analysis

尽管有许多系统的研究，狗科中许多物种之间的关系仍然没有解决。有两个领域一直存在分歧，那就是类狼物种（犬科、昆科、狼科和猎狼属）和南美物种（5-7属）。这两个类群总共包括大约20个物种，占犬科动物总数的一半以上。先前基于形态学、同工酶变异和核学的研究未能提供这些分类群之间关系的一致图像。在很大程度上，缺乏成功的分子分析是由于许多这些物种之间的密切关系。这些密切相关的分类群之间的关联最好通过更精细的分子分析来研究，例如基于线粒体DNA序列数据的分析。本文建议对基因组DNA聚合酶链扩增（PCR）获得的约850个碱基对线粒体DNA序列进行系统发育分析，以检验有关这些分类群系统分类学的几个特定假设。由于哺乳动物线粒体DNA序列的进化速度很快（比平均核序列快5-10倍），因此特别适合研究近亲物种。这些犬科动物中的许多物种一直是食肉动物行为比较研究的焦点，因此解决它们之间的关系将阐明祖先对观察模式的潜在影响。

Despite numerous systematic studies, the relationships among many species within the dog family Canidae remain unresolved. Two areas of continued disagreement are the wolf-like species (in the genera Canis, Cuon,Lycaon, and Speothos) and the South American species (in 5-7 genera). Together the two groups include some 20 species, or more than half of those within the family Canidae. Previous work based on morphology, allozyme variation, and karyology have failed to provide a consistent picture of relationships among these taxa. In large part, the lack of success of the molecular analyses was due to the close relationships among many of these species. Associations among such closely related taxa are best studied with more fine-scale molecular analyses, such as those based on mitochondrial DNA sequence data. Here, it is proposed to test several specific hypotheses concerning the systematics of these taxa using phylogenetic analysis of approximately 850 base pairs of mitochondrial DNA sequence obtained by polymerase chain amplification (PCR) of genomic DNA. Because the mitochondrial DNA sequence of mammals evolves quickly (5-10 times faster than the average nuclear sequence), it is particularly appropriate for the study of closely related species. Many of these canid species have been the focus of comparative studies of carnivore behavior and thus resolution of their relationships will illuminate the potential effects of ancestry on observed patterns.