Sponsor
Portland State University. Department of Biology
First Advisor
Richard Forbes
Term of Graduation
Fall 1976
Date of Publication
11-24-1976
Document Type
Thesis
Degree Name
Master of Science (M.S.) in Biology
Department
Biology
Language
English
Subjects
Vagrant shrew -- Genetics, Vagrant shrew -- Morphology, Gene flow
DOI
10.15760/etd.2550
Physical Description
1 online resource (xii, 61 pages)
Abstract
Twenty-one morphological characters were measured in shrews from four islands in the Columbia River and from the adjacent Oregon and Washington shores. Information on the history and characteristics of the river islands was gathered to facilitate interpretation of the shrew’s morphology data. Significant differences between character means of different populations were detected and average taxonomic distances between pairs of populations were calculated. The Columbia River is an incomplete barrier to gene flow, but its influence has been sufficient to allow divergence of island populations. Natural selection on the small gene pools of island populations has probably contributed to the divergence. Shrews most likely reached the islands from the mainlands by rafting on floating vegetation and debris. Morphometric comparison of island populations seems to provide a more sensitive indication of restricted gene flow than similar comparison of opposite mainland populations.
Rights
In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
Persistent Identifier
https://archives.pdx.edu/ds/psu/16167
Recommended Citation
Kirk, James J., "The Columbia River as a Barrier to Gene Flow in the Vagrant Shrew, Sorex vagrans vagrans Baird" (1976). Dissertations and Theses. Paper 2553.
https://doi.org/10.15760/etd.2550
Comments
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