Saarma Urmas, Ho Simon Y W, Pybus Oliver G, Kaljuste Marju, Tumanov Igor L, Kojola Ilpo, Vorobiev Alex A, Markov Nikolai I, Saveljev Alexander P, Valdmann Harri, Lyapunova Elena A, Abramov Alexei V, Männil Peep, Korsten Marju, Vulla Egle, Pazetnov Sergei V, Pazetnov Valentin S, Putchkovskiy Stanislav V, Rõkov Alexander M
Department of Integrative Zoology, Institute of Zoology and Hydrobiology, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia.
Mol Ecol. 2007 Jan;16(2):401-13. doi: 10.1111/j.1365-294X.2006.03130.x.
We estimated the phylogenetic relationships of brown bear maternal haplotypes from countries of northeastern Europe (Estonia, Finland and European Russia), using sequences of mitochondrial DNA (mtDNA) control region of 231 bears. Twenty-five mtDNA haplotypes were identified. The brown bear population in northeastern Europe can be divided into three haplogroups: one with bears from all three countries, one with bears from Finland and Russia, and the third composed almost exclusively of bears from European Russia. Four haplotypes from Finland and European Russia matched exactly with haplotypes from Slovakia, suggesting the significance of the current territory of Slovakia in ancient demographic processes of brown bears. Based on the results of this study and those from the recent literature, we hypothesize that the West Carpathian Mountains have served either as one of the northernmost refuge areas or as an important movement corridor for brown bears of the Eastern lineage towards northern Europe during or after the last ice age. Bayesian analyses were performed to investigate the temporal framework of brown bear lineages in Europe. The molecular clock was calibrated using Beringian brown bear sequences derived from radiocarbon-dated ancient samples, and the estimated mutation rate was 29.8% (13.3%-47.6%) per million years. The whole European population and Western and Eastern lineages formed about 175,000, 70,000 and 25,000 years before present, respectively. Our approach to estimating the time frame of brown bear evolution demonstrates the importance of using an appropriate mutation rate, and this has implications for other studies of Pleistocene populations.
我们利用231只熊的线粒体DNA（mtDNA）控制区序列，估计了来自欧洲东北部国家（爱沙尼亚、芬兰和俄罗斯欧洲部分）的棕熊母系单倍型的系统发育关系。共鉴定出25种mtDNA单倍型。欧洲东北部的棕熊种群可分为三个单倍群：一个包含来自所有三个国家的熊，一个包含来自芬兰和俄罗斯的熊，第三个几乎完全由来自俄罗斯欧洲部分的熊组成。来自芬兰和俄罗斯欧洲部分的四种单倍型与来自斯洛伐克的单倍型完全匹配，这表明斯洛伐克当前的领土在棕熊古代种群动态过程中具有重要意义。基于本研究结果和近期文献，我们推测西喀尔巴阡山脉在末次冰期期间或之后，要么是最北部的避难区之一，要么是东部谱系棕熊向北欧迁移的重要通道。我们进行了贝叶斯分析，以研究欧洲棕熊谱系的时间框架。分子钟使用来自放射性碳测年古代样本的白令海棕熊序列进行校准，估计的突变率为每百万年29.8%（13.3%-47.6%）。整个欧洲种群以及西部和东部谱系分别在距今约175,000年、70,000年和25,000年前形成。我们估计棕熊进化时间框架的方法证明了使用适当突变率的重要性，这对其他更新世种群研究具有启示意义。
