Summary: | Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item. Includes bibliographical references: p. 43-50. Analyses of restriction fragment length polymorphisms hics. (RFLP's) and sequence variation in the ND3, ND4L, and ND4 mitochondrion genes were used to determine the identity and distribution of Peromyscus from Yukon Territory, Canada and southeastern Alaska. The RFLP data indicated the presence and occasional sympathy of Peromyscus maniculatus and P. keens in this region. The sequence data, however, indicated the presence of a third mtDNA lineage generally sympatric with P. keens in south central and south western Yukon. This third lineage displayed RFLP haplotypes identical to those of P. maniculatus and thus, was termed the P. maniculatus-RFLP-cryptic lineage. The average genetic distances (Tamura and Nei 1993) between the P. maniculatus-RFLP-cryptic and the P. maniculatus and the P. keens lineages were .043 and .046, respectively, This suggests that the P. maniculatus-RFLP-cryptic lineage is as ancient as are the P. maniculatus and P. keens lineages. Additionally, these values of genetic distance are comparable to those between sister species within the P. maniculatus species group. Genetic differentiation among these populations is proposed to have resulted from isolation in glacial refugia in southwestern Yukon and along the Pacific Northwest coast in the early Pleistocene, predating the Wisconsin. This pattern is concordant with the speciation model in Which P keens and the mice of the P. maniculatus-RFLP-cryptic lineages are recent peripheral isolates from an ancestral P maniculatus central stock.
|