利用几何形态测量学方法分析外来近似物种形态差异与亲疏关系

Using geometric morphometrics to discuss the shape variation and taxonomical similarities of exotic species separately introduced to different regions

几何形态测量学方法是近年来生物形态学研究的热点方法。利用此方法对分类存疑的法国、比利时和意大利3处外来的丽松鼠属松鼠(Callosciurus sp.)下颌骨形态进行了比较分析,结果表明:1)所有种群均有显著的异速生长效应,个体间形变主要发生在冠状突、隅突、咬肌嵴和颏孔位置,而种群间形变主要发生在隅突部分;2)判别函数分析表明,三地种群具明显形态差异,但法国种群较其他两者距离更远,而比利时与意大利种群则亲缘关系较近,由此推断后两者的外来种群可能来自同一来源或同一分类地位物种,而法国外来种群可能来自与比利时和意大利种群属不同分类地位,三者间的下颌形态变化可能与各自地理生态适应相关。研究定量和图形化了各外来种群间的下颌形变差异与分类亲疏程度,有利于进一步弄清外来物种来源与分类学地位,从而为入侵生物形态学研究提供科学参考。

Geometric morphometrics has been applied as a hot method for biological morphology research in recent years. In this study,geometric morphometrics was used to discuss the taxonomical similarities towards an exotic squirrel species( Callosciurus sp.) introduced separately into France,Belgium and Italy,by analyzing the mandibular shape. The results showed allometry effect can be found with statistical significance throughout all introduced populations,shape variations individually happened at coronoid process,angular process,masseteric ridge,and mental foramen of mandible,while among populations,shape varied largely at angular process;discriminant function analysis indicated the mandibular shapes of three introduced populations significantly differed,in which the French exotic population was more far from the other two,and Belgian and Italian populations were more closer to each other,so,we can deduce the exotic squirrels introduced into Belgium and Italy may belong to same species or origin,and the French introduced squirrel belongs to different one. And,the variations in mandibular shape among them may result from the respective ecological adaptation in different geographic regions. The subtle shape variation and taxonomical differences were investigated and visualized by means of geometric morphormetrics in this paper,which could be useful to taxonomically classify the exotic species and explore the introduced origin,and be referenced for biological morphology of invasive creatures.