BACKGROUND In Europe the mountain hare (Lepus timidus) exists in Great Britain, Norway, Sweden, Finland, parts of the Alps and in Eastern Europe, but not in Denmark. Interspecific hybridization has been demonstrated between native Swedish mountain hares and introduced brown hares (Lepus europaeus). During the data collection in a study concerning Danish brown hares we identified 16 hares with a single very divergent haplotype. RESULTS Phylogenetic analysis shows that the divergent Danish haplotype is most closely related to the Swedish mountain hare. The frequency of Lepus timidus mtDNA haplotype in the Eastern Danish hare populations is estimated to 6%. CONCLUSION In contrast to what is known, the Danish hare populations are not pure L. europaeus populations but include introgressed brown hares with Swedish L. timidus mtDNA. The most probable explanation of this is natural migration or translocation of introgressed brown hares from Sweden. The impurity of hare populations has implications for conservation and population genetics.

中文翻译：

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在丹麦，野兔（Lepus timidus）线粒体DNA渗入野生棕色野兔（Lepus europaeus）。

背景技术在欧洲，山野兔（Lepus timidus）存在于英国，挪威，瑞典，芬兰，部分阿尔卑斯山和东欧，但在丹麦不存在。种间杂交已在瑞典本地山区野兔和引进的棕色野兔（欧洲兔）之间进行了证明。在一项有关丹麦棕兔的研究中，我们收集了数据，在此基础上，我们确定了16个具有单一单倍型的兔。结果系统发育分析表明，不同的丹麦单倍型与瑞典山区野兔最密切相关。丹麦东部野兔种群中Lepus timidus mtDNA单倍型的频率估计为6％。结论与已知的相反，丹麦的野兔种群不是纯欧洲木虱种群，而是包括带有瑞典小.L。mtDNA的渗入棕色野兔。对此的最可能解释是来自瑞典的渗入褐兔的自然迁移或易位。野兔种群的杂质对保护和种群遗传学有影响。