Hänni C, Laudet V, Stehelin D, Taberlet P
Centre National de la Recherche Scientifique Unité de Recherche Associée 1160, Oncologie Moléculaire, Institut Pasteur, Lille.
Proc Natl Acad Sci U S A. 1994 Dec 6;91(25):12336-40. doi: 10.1073/pnas.91.25.12336.
The different European populations of Ursus arctos, the brown bear, were recently studied for mitochondrial DNA polymorphism. Two clearly distinct lineages (eastern and western) were found, which may have diverged approximately 850,000 years ago. In this context, it was interesting to study the cave bear, Ursus spelaeus, a species which became extinct 20,000 years ago. In this study, we have amplified and sequenced a fragment of 139-bp in the mitochondrial DNA control region of a 40,000-year-old specimen of U. spelaeus. Phylogenetic reconstructions using this sequence and the European brown bear sequences already published suggest that U. spelaeus diverged from an early offshoot of U. arctos--i.e., approximately at the same time as the divergence of the two main lineages of U. arctos. This divergence probably took place at the earliest glaciation, likely due to geographic separation during the earlier Quaternary cold periods. This result is in agreement with the paleontological data available and suggests a good correspondence between molecular and morphological data.
最近对欧洲不同种群的棕熊（ Ursus arctos）进行了线粒体DNA多态性研究。发现了两个明显不同的谱系（东部和西部），它们可能在大约85万年前就已经分化。在这种背景下，研究洞熊（Ursus spelaeus）很有意思，洞熊是一种在2万年前灭绝的物种。在这项研究中，我们对一个4万年前的洞熊标本的线粒体DNA控制区中一段139bp的片段进行了扩增和测序。使用该序列和已发表的欧洲棕熊序列进行的系统发育重建表明，洞熊是从棕熊的一个早期分支分化而来的——也就是说，大约与棕熊两个主要谱系的分化时间相同。这种分化可能最早发生在冰川期，可能是由于第四纪早期寒冷时期的地理隔离。这一结果与现有的古生物学数据一致，表明分子数据和形态数据之间具有良好的对应关系。
