• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Evolution and Development of Diversity: An Example in Foraging Morphology of Soricid Shrews

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_etd_2690_sip1_m.pdf
    Size:
    2.230Mb
    Format:
    PDF
    Description:
    azu_etd_2690_sip1_m.pdf
    Download
    Author
    Young, Rebecca Lynn
    Issue Date
    2008
    Keywords
    adaptation
    diversification
    morphological evolution
    phenotypic integration
    plasticity
    Advisor
    Badyaev, Alexander V
    Committee Chair
    Badyaev, Alexander V
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    Rights
    Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
    Abstract
    Divergent natural selection for use of locally abundant resources can lead to diversification within and across species. However, the consequences of divergent selection for phenotypic evolution also depend on the development of variation. Because relationships among traits such as shared developmental timing or common involvement in an organismal function can channel variation generated during development, these relationships strongly influence the direction of evolution.During development of the mammalian mandible multiple tissues of distinct developmental origins interact with inputs from the functioning of attached muscles to produce a cohesive and well integrated trait. In soricid shrews, part of the mandible matures late in ontogeny, coinciding with the onset of foraging. In this case, foraging-linked muscle activity should influence the development of the late maturing mandibular region. Here, I show that variation in this late ossifying region reveals the local functional requirements of the jaw and results in an opportunity to decouple internal and external sources of variation (developmental and environmental respectively) in the mandible. Capitalizing on this feature of the Sorex system, I empirically examined the historical persistence of internal and external patterns of variation, the consequences of variation patterning for ecological and morphological diversification across taxa, and differences between early and late ossifying regions in their contribution to local adaptation in mandible morphology.I found that the functional requirements of diet directed mandible development and determined species similarity in both mandible morphology and function. Timing of bone maturation determined the morphological effects of foraging-linked muscle activity, resulting in differential expression of adaptive variation in the late maturing region. Further, I found higher levels of interspecific variation in the late maturing region of the mandible, and showed that interspecific divergence in foraging morphology occurs along the lines delineated by epigenetic inputs of muscle on bone formation during late ontogeny within species. These findings indicate that differences in functional requirements are critical for divergence among taxa in this system. Further, these results suggest that, when external inputs into trait development are indicative of local functional requirements, the same epigenetic mechanism of development can generate diversity both within and among taxa.
    Type
    text
    Electronic Dissertation
    Degree Name
    PhD
    Degree Level
    doctoral
    Degree Program
    Ecology & Evolutionary Biology
    Graduate College
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.