Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Wallace, Lisa

Committee Member

Welch, Mark E.

Committee Member

Ervin, Gary N.

Date of Degree

1-1-2013

Document Type

Graduate Thesis - Open Access

Major

Botany

Degree Name

Master of Science

College

College of Arts and Sciences

Department

Department of Biological Sciences

Abstract

The California Channel Islands present an ideal system in which to study unique biogeographical patterns seen in island systems near a mainland source, where spatial barriers are likely to limit gene flow without disrupting it completely. The islands also harbor a number of endemic taxa, suggesting that isolation from the mainland may be strong for some taxa. For this study, Acmispon argophyllus, a legume species found across five of the eight islands as well as on the mainland was used to test hypotheses at three spatial scales. Northern island populations have diverged into what potentially represents a new species; populations on the younger southern islands descent from populations on the older island of San Clemente; the two taxa on San Clemente show signs of genetic structure, with limited evidence of ongoing gene flow. These results demonstrate isolation over short distances in the Channel Islands leading to evolutionary divergence and speciation.

URI

https://hdl.handle.net/11668/19041

Comments

close islands||conservation||Channel Islands||Acmispon||biogeography||island endemism||genetic structure

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