非洲穿山甲目前正在经历前所未有的收获水平,满足当地需求和非法国际贸易。到目前为止,缺乏对非洲穿山甲种群遗传学的了解,阻碍了评估其人口状况和在当地追踪其贸易的任何尝试。我们对达荷美Gap(DG)中非洲穿山甲贸易的遗传追踪进行了先驱研究。我们使用一个线粒体片段和20个微卫星基因座,对来自18个森林和12个野生动植物市场的189个白腹穿山甲进行了测序和基因分型。
基于树的分配程序表明,穿山甲贸易是DG地区特有的,因为它是由达荷美Gap谱系(DGL)严格喂养的。DGL种群的特征是遗传多样性水平低,总体上缺乏平衡,重要的近亲繁殖水平,缺乏地理结构。我们确定了DGL有效人口规模200-500ya下降了92-98%-伴随着“奴隶海岸”的重大政治变革-导致同期估计低于最低可行人口规模(<500)。遗传追踪表明,来自DG的野生动物市场在整个DGL范围内都采购穿山甲。我们的基因座提供了必要的力量来区分所有基因分型的穿山甲,在市场上和当地社区内追踪同一个人的派遣。我们开发了一种方法,该方法将私有等位基因频率的稀疏分析与观察到的数据的交叉验证相结合,该数据将五种交易的穿山甲追踪到其森林起源,c.距离市场200-300公里。
尽管我们从传统标记物设计的遗传工具包可以证明有助于追踪穿山甲的非法贸易,我们的追踪能力受到DGL内部缺乏人口结构的限制。鉴于遗传的有害组合,人口统计学,以及影响DGL人口的贸易相关因素,DG中白腹穿山甲的保护状况应紧急重新评估。
African pangolins are currently experiencing unprecedented levels of harvesting, feeding both local demands and the illegal international trade. So far, the lack of knowledge on the population genetics of African pangolins has hampered any attempts at assessing their demographic status and tracing their trade at the local scale. We conducted a pioneer study on the genetic tracing of the African pangolin trade in the Dahomey Gap (DG). We sequenced and genotyped 189 white-bellied pangolins from 18 forests and 12 wildlife markets using one mitochondrial fragment and 20 microsatellite loci.
Tree-based assignment procedure showed that the pangolin trade is endemic to the DG region, as it was strictly fed by the the Dahomey Gap lineage (DGL). DGL populations were characterized by low levels of genetic diversity, an overall absence of equilibrium, important inbreeding levels, and lack of geographic structure. We identified a 92-98% decline in DGL effective population size 200-500 ya-concomitant with major political transformations along the \'Slave Coast\'-leading to contemporaneous estimates being inferior to minimum viable population size (< 500). Genetic tracing suggested that wildlife markets from the DG sourced pangolins through the entire DGL range. Our loci provided the necessary power to distinguish among all the genotyped pangolins, tracing the dispatch of a same individual on the markets and within local communities. We developed an approach combining rarefaction analysis of private allele frequencies with cross-validation of observed data that traced five traded pangolins to their forest origin, c. 200-300 km away from the markets.
Although the genetic toolkit that we designed from traditional markers can prove helpful to trace the illegal trade in pangolins, our tracing ability was limited by the lack of population structure within the DGL. Given the deleterious combination of genetic, demographic, and trade-related factors affecting DGL populations, the conservation status of white-bellied pangolins in the DG should be urgently re-evaluated.