Abstract: In this research,we comprehensively compared skulls of Apodemus chevrieri populations in the western Sichuan
Mountains, including the Minshan, Qionglai, Xiangling and Liangshan Mountains, which are isolated from each other by broad rivers or extensive human activities. One-way ANOVA and subsequent multiple comparisons indicated that one or more variables were significantly different among these isolated populations For all samples,the discriminant function analysis had 69.7% correct ratio. Significant differences in skull morphology in these populations implied that significant geographical differentiation had occurred among them. In addition,geographical distance was significantly positively correlated with difference in discriminant scores of skulls. We assumed that besides geographical distance,the difference in skulls among different populations was also related to selective pressures from their local environmental conditions. Our results indicated that future research should pay more attention to potential geographical differentiation in morphological traits when defining
species within the Apodemus genus.

Key words: Apodemus chevrieri, Geographical differentiation, Mountains, Skull

摘要： 本文以我国特有的小型兽类高山姬鼠(Apodemus chevrieri)为例,探讨了其头骨特征在四川西部岷山、邛崃山、相岭及凉山等隔离山系中的异同。单因素方差分析结果表明,不同山系高山姬鼠头骨在多数形态指标上存在显著差异,多重比较结果显示出各山系间至少1 至多个头骨量度存在显著不同。除此之外,多元判别分析进一步将69.7% 的样本正确地判归各来源山系,表明各山系高山姬鼠种群已发生了显著分化。头骨样品地理距离与判断得分距离之间的显著性正相关说明高山姬鼠种群在四川西部不同山系的头骨分化可能与空间距离有密切的联系。本项研究揭示了在根据形态特征进行姬鼠属(Apodemus)内物种阶元的划分时,必须充分考虑性状特征可能存在的地理差异。