ERA

Download the full-sized PDF of Morphological plasticity of barnacle feeding legs and penisesDownload the full-sized PDF

Analytics

Share

Permanent link (DOI): https://doi.org/10.7939/R30T4N

Download

Export to: EndNote  |  Zotero  |  Mendeley

Communities

This file is in the following communities:

Graduate Studies and Research, Faculty of

Collections

This file is in the following collections:

Theses and Dissertations

Morphological plasticity of barnacle feeding legs and penises Open Access

Descriptions

Other title
Subject/Keyword
Phenotypic Plasticity
Genitalia
Cirrepedia
Barnacle
Type of item
Thesis
Degree grantor
University of Alberta
Author or creator
Neufeld, Chris
Supervisor and department
Palmer, A. Richard (Biological Sciences)
Examining committee member and department
Lewis, Mark (Biological Sciences)
Proctor, Heather (Biological Sciences)
Department
Department of Biological Sciences
Specialization

Date accepted
2011-05-02T20:25:45Z
Graduation date
2011-11
Degree
Doctor of Philosophy
Degree level
Doctoral
Abstract
One important source of phenotypic variation on which natural selection can act is developmental plasticity (the capacity of a single genotype to produce different environment-dependent forms). Therefore, studies of how the environment influences development can facilitate our understanding of how natural selection acts to yield phenotypic evolution. Using the Pacific barnacle (Balanus glandula Darwin), I explored how functionally independent appendages (the legs and unusually long penises of barnacles) respond to widespread spatial and temporal variation in water velocity and conspecific density. Through field surveys, reciprocal transplant experiments, and histological sectioning, I show that barnacle legs and penises appear remarkably well adapted to spatial and temporal variation in water velocity. Building on past work on leg form variation, I show that penises from exposed shores were shorter than, stouter than, and more than twice as massive for their length, as those from nearby protected bays (this effect holds true for artificially inflated penises as well). A transplant experiment confirmed that most of this variation in penis and leg form variation was due to developmental plasticity. Penises and legs of barnacles from an exposed shore also had thicker cuticle, and muscles with greater cross-sectional area (and shorter sarcomeres) compared to those from a protected shore. Form variation was consistent with numerous predictions from engineering theory suggesting that barnacles show dramatic, complex and likely adaptive variation in leg and penis form among sites that differ dramatically in water velocity. Additional experiments showed evidence for and against developmental limits to plasticity in barnacles. A transplant experiment identified an important (and asymmetrical) developmental limit to leg-length response time – likely mediated by food limitation – while a field survey showed that developmental coupling does not restrict adaptive plastic responses of legs and penises to multiple conflicting cues (conspecific density and water velocity). Finally, a two-year survey of natural populations revealed the first evidence that barnacles also change leg form seasonally. Together these results contribute valuable information on the mechanisms of phenotypic change. This research also sheds light on the circumstances that allow decoupling of developmental processes to produce novel combinations of characters on which natural selection can act.
Language
English
DOI
doi:10.7939/R30T4N
Rights
Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
Citation for previous publication

File Details

Date Uploaded
Date Modified
2014-04-24T22:21:07.668+00:00
Audit Status
Audits have not yet been run on this file.
Characterization
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 6530254
Last modified: 2015:10:12 16:26:02-06:00
Filename: Neufeld_Chris_Fall_2011.pdf
Original checksum: e777617900929eb8e1a490db4952d752
Well formed: true
Valid: true
File title: Microsoft Word - Thesis_10.doc
File author: Chris
Page count: 151
Activity of users you follow
User Activity Date