Wildlife Disease Unit, Fisheries and Wildlife Management Division, Government of Alberta, Edmonton, Alberta, Canada.
Forensic Sci Int Genet. 2011 Jan;5(1):50-6. doi: 10.1016/j.fsigen.2010.02.002. Epub 2010 Mar 5.
Forensic science techniques are an important component of investigations for wildlife-related offences. In particular, DNA analyses can be used to characterize several attributes of biological evidence including sex, individual and species identification. Additionally, genetic assignment testing has enabled forensic biologists to identify the local population from which an individual may have originated. This technique has proved useful in situations where animals have been illegally harvested from areas/populations where hunting is prohibited. For this report, we used individual-based clustering (IBC), in the program Structure 2.2, under both "supervised" and "unsupervised" approaches to assess whether three suspected, illegally harvested moose originated from an endangered population. Atypical circumstances, with Nova Scotia having two moose sub-species in its jurisdiction, enabled strong IBC assignment testing results to determine the source population of the suspected samples. We found differences between the "unsupervised" and "supervised" modeling approaches to define genetic structure among the a priori characterized populations in our data set. Our findings illustrate the fact that individual clustering assignment tests can assist wildlife forensic cases to identify the source population of illegally harvested animals. However, the accuracy of results are highly dependant on the model choice used to define genetic clusters, as well as on the availability of a thorough database of samples throughout the managed area to accurately identify all genetic populations. Further, it is clear from our analyses that political jurisdictions do not accurately reflect isolated populations and we recommend using unsupervised IBC modeling for biological accuracy.
法医科学技术是与野生动物相关犯罪调查的重要组成部分。特别是，DNA 分析可用于描述生物证据的几个特征，包括性别、个体和物种识别。此外，遗传分配测试使法医生物学家能够识别个体可能起源的本地种群。这项技术在从禁止狩猎的地区/种群非法采集动物的情况下非常有用。在本报告中，我们使用了基于个体的聚类（IBC），在程序 Structure 2.2 下，采用“监督”和“无监督”方法，评估三个涉嫌非法采集的驼鹿是否来自濒危种群。新斯科舍省管辖范围内有两个驼鹿亚种，这种特殊情况使强烈的 IBC 分配测试结果能够确定疑似样本的来源种群。我们发现，在我们数据集的先验特征种群中，“无监督”和“监督”建模方法之间存在遗传结构差异。我们的研究结果表明，个体聚类分配测试可以帮助野生动物法医案件确定非法采集动物的来源种群。然而，结果的准确性高度依赖于用于定义遗传聚类的模型选择，以及在整个管理区域内是否有一个全面的样本数据库来准确识别所有遗传种群。此外，从我们的分析中可以清楚地看出，政治管辖范围不能准确反映孤立的种群，我们建议使用无监督的 IBC 建模以提高生物学准确性。
