Cognitive Ethology Laboratory, German Primate Center, Göttingen, Germany.
Am J Phys Anthropol. 2013 Jan;150(1):133-40. doi: 10.1002/ajpa.22185. Epub 2012 Nov 26.
Baboons (genus Papio) are an interesting phylogeographical primate model for the evolution of savanna species during the Pleistocene. Earlier studies, based on partial mitochondrial sequence information, revealed seven major haplogroups indicating multiple para- and polyphylies among the six baboon species. The most basal splits among baboon lineages remained unresolved and the credibility intervals for divergence time estimates were rather large. Assuming that genetic variation within the two studied mitochondrial loci so far was insufficient to infer the apparently rapid early radiation of baboons we used complete mitochondrial sequence information of ten specimens, representing all major baboon lineages, to reconstruct a baboon phylogeny and to re-estimate divergence times. Our data confirmed the earlier tree topology including the para- and polyphyletic relationships of most baboon species; divergence time estimates are slightly younger and credibility intervals narrowed substantially, thus making the estimates more precise. However, the most basal relationships could not be resolved and it remains open whether (1) the most southern population of baboons diverged first or (2) a major split occurred between southern and northern clades. Our study shows that complete mitochondrial genome sequences are more effective to reconstruct robust phylogenies and to narrow down estimated divergence time intervals than only short portions of the mitochondrial genome, although there are also limitations in resolving phylogenetic relationships.
狒狒（属 Papio）是灵长类动物中一个有趣的系统地理学模型，用于研究更新世期间草原物种的进化。早期的研究基于部分线粒体序列信息，揭示了七个主要的单倍型群体，表明在六种狒狒物种中存在多种并系和多系现象。狒狒谱系之间最基础的分支仍然没有得到解决，并且分歧时间估计的置信区间相当大。假设到目前为止，在两个研究的线粒体基因座内的遗传变异不足以推断狒狒的早期快速辐射，我们使用了十个代表所有主要狒狒谱系的标本的完整线粒体序列信息来重建狒狒系统发育并重新估计分歧时间。我们的数据证实了早期的树拓扑结构，包括大多数狒狒物种的并系和多系关系；分歧时间估计稍年轻，置信区间大大缩小，从而使估计更加精确。然而，最基础的关系仍然无法解决，仍然存在争议，即（1）最南部的狒狒种群首先分化，还是（2）在南部和北部支系之间发生了主要的分裂。我们的研究表明，完整的线粒体基因组序列比仅短的线粒体基因组部分更有效地重建稳健的系统发育并缩小估计的分歧时间间隔，尽管在解决系统发育关系方面也存在局限性。
