The spectacled bear (Ursidae: Tremarctos ornatus) is an emblematic umbrella species and one of the top carnivores in the Andean mountains. It is also listed as vulnerable by IUCN and as endangered by CITES. We analyzed the genetic structure of this species in nine geographical regions representing the three Andean Cordilleras in Colombia. We sequenced six mitochondrial genes in 115 spectacled bears; a subset of these specimens (n = 61) were genotyped at seven nuclear microsatellites. We addressed three objectives: 1) determine the genetic diversity and historical demographic changes of the spectacled bear in Colombia; 2) determine phylogeographic patterns of genetic divergence among spectacled bear populations in Colombia; and 3) estimate the levels of gene flow among different regions of Colombia. Our analyses show evidence of high mitochondrial genetic diversity in spectacled bears, both in Colombia as well as in each of the nine regions, most particularly Norte de Santander, Nariño, and Antioquia-Córdoba. In addition, we detected population expansion in Colombia that occurred around 24,000 years ago, followed by a population decrease during the last 7,000 years, and a sudden expansion in the last 300 years. Phylogenetic analyses showed few well-supported clades, with some haplotypes detected in all the departments and Colombian Andean Cordilleras, and other haplotypes restricted to certain geographical areas (Antioquia, Norte de Santander, Cundinamarca, and Nariño). We detected significant genetic heterogeneity among some departments and among the three Colombian Andean Cordilleras for both mitochondrial and nuclear genes. Nevertheless, the moderate levels of gene flow estimated from FST statistics suggest that geographical barriers have not been definitive obstacles to the dispersion of the spectacled bear throughout Colombia. Despite these gene flow estimates, significant spatial autocorrelation was detected for spectacled bear in Colombia, where two kinds of spatial patterns were discovered: genetic patches of 144 km of diameter, and isolation by distance among bears separated from 578 to 800 km. The two most northern spectacled bear populations of Colombia (Norte de Santander and Antioquia) also were the two most differentiated. Their distinctiveness may qualify them as distinct Management Units (MUs) in the context of conservation policies for the spectacled bear in Colombia.

中文翻译：

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通过线粒体和微卫星标记的哥伦比亚眼镜熊（Tremarctos ornatus；熊科，食肉目）的遗传结构

眼镜熊（熊科：Tremarctos ornatus）是一种象征性的伞形物种，也是安第斯山脉的顶级食肉动物之一。它也被 IUCN 列为易危物种，并被 CITES 列为濒危物种。我们分析了该物种在代表哥伦比亚三个安第斯山脉的九个地理区域的遗传结构。我们对 115 只眼镜熊的 6 个线粒体基因进行了测序；这些标本的一个子集（n = 61）在七个核微卫星上进行了基因分型。我们解决了三个目标：1) 确定哥伦比亚眼镜熊的遗传多样性和历史人口变化；2) 确定哥伦比亚眼镜熊种群遗传差异的系统地理学模式；3) 估计哥伦比亚不同地区之间的基因流动水平。我们的分析表明，眼镜熊在哥伦比亚以及九个地区，尤其是北桑坦德、纳里尼奥和安蒂奥基亚-科尔多瓦，都具有高度的线粒体遗传多样性。此外，我们检测到哥伦比亚的人口扩张发生在大约 24,000 年前，随后是过去 7,000 年的人口减少，以及过去 300 年的突然扩张。系统发育分析显示很少有充分支持的进化枝，在所有部门和哥伦比亚安第斯山脉中检测到一些单倍型，而其他单倍型仅限于某些地理区域（安蒂奥基亚、北桑坦德、昆迪纳马卡和纳里尼奥）。我们在某些部门和三个哥伦比亚安第斯山脉之间检测到线粒体和核基因的显着遗传异质性。尽管如此，根据 FST 统计数据估计的中等水平的基因流表明，地理障碍并不是眼镜熊在哥伦比亚扩散的决定性障碍。尽管有这些基因流估计，但哥伦比亚眼镜熊仍检测到显着的空间自相关，在那里发现了两种空间模式：直径为 144 公里的遗传斑块，以及相距 578 至 800 公里的熊之间的距离隔离。哥伦比亚最北部的两个眼镜熊种群（北桑坦德和安蒂奥基亚）也是差异最大的两个种群。在哥伦比亚眼镜熊保护政策的背景下，它们的独特性可能使它们成为独特的管理单位 (MU)。