Sleeping with the ‘enemy’ - Hybridization of an endangered tree weta

While hybridization is an important part of the evolutionary process, for rare species mating with more common species hybridization can increase the risks of extinction. By mating with heterospecifics rare species waste valuable reproductive resources and as a result population sizes may decline. If introgression occurs, the rare species can become genetically swamped by alleles from the more common species, rendering it effectively extinct. As a consequence of these risks, hybridization with the more common species Hemideina femorata (Canterbury tree weta) may lead to the extinction of the range restricted species H. ricta (Banks Peninsula tree weta) on Banks Peninsula. The current study uses spatial interpolation to model the distribution of each species and the potential sympatric zone to guide sampling efforts. Polymorphic microsatellite markers and mitochondrial sequence data were used to determine the extent of hybridization between H. ricta and H. femorata. The results confirm t...

尽管杂交是演化进程中的关键环节之一，但对于珍稀物种而言，与常见物种杂交会加剧其灭绝风险。通过与异种个体交配，珍稀物种会浪费宝贵的繁殖资源，进而引发种群规模缩减。若发生基因渐渗（introgression），珍稀物种的基因组可被常见物种的等位基因（allele）完全淹没，实质上等同于该物种的功能性灭绝。
鉴于上述风险，与常见物种坎特伯雷树沙螽（Hemideina femorata）的杂交行为，可能导致分布范围受限的班克斯半岛树沙螽（H. ricta）在班克斯半岛走向灭绝。
本研究采用空间插值（spatial interpolation）法对两个物种的分布及潜在同域分布区进行建模，以指导采样工作；同时借助多态微卫星标记（microsatellite marker）与线粒体序列数据，分析H. ricta与H. femorata之间的杂交程度。研究结果证实了……