How environments shape ornament morphological evolution: bringing perspective to a century of inconsistent sexual allometry analysis
type: CreativeWork
description: The diversity of complex morphologies species use for social communication is reflected by their wide range of functions. Many operate as part of either threat displays or facilitate mate choice, while others may perform dual roles. Measuring the extent species disproportionately invest in these sexual morphologies is a primary means of assessing their various adaptive functions. However, this analysis (i.e., allometry) often produces inconsistent outcomes that undermine its effectiveness. To this end, I investigated whether different sexual structures always evolve similar allometric patterns, and how the environment might prevent this from happening. The second chapter evaluates how locomotion in different environments cause related species to evolve variable sexual allometries. Among a highly social group of intertidal Blenniid fish, underwater species were found to invest in markedly smaller ornament allometries compared to their terrestrial relatives, demonstrating inconsistent sexual allometries can be caused by biomechanical restrictions unique to a species environment. For my third Chapter I used a meta-analysis to reveal female preference experiments generally failed to present females with male display structure sizes informed by allometric data. This implies questions central to sexual allometry theory – that female preferences drive the evolution of disproportionately larger male sexual structures – are yet to be formally tested in an experimental setting. I designed such an experiment using realistic models of a terrestrial Blenniid fish species from Chapter two. Its findings indicate, in the absence of environmental constraints, female preferences can support the evolution of disproportionate scaling among sexual allometries. Finally, in Chapter four I expand upon my findings in Chapter two and explore additional ways the environment might restrict sexual allometric relationships. Specifically, its influence upon the visual efficacy of these structures…
abstract: The diversity of complex morphologies species use for social communication is reflected by their wide range of functions. Many operate as part of either threat displays or facilitate mate choice, while others may perform dual roles. Measuring the extent species disproportionately invest in these sexual morphologies is a primary means of assessing their various adaptive functions. However, this analysis (i.e., allometry) often produces inconsistent outcomes that undermine its effectiveness. To this end, I investigated whether different sexual structures always evolve similar allometric patterns, and how the environment might prevent this from happening. The second chapter evaluates how locomotion in different environments cause related species to evolve variable sexual allometries. Among a highly social group of intertidal Blenniid fish, underwater species were found to invest in markedly smaller ornament allometries compared to their terrestrial relatives, demonstrating inconsistent sexual allometries can be caused by biomechanical restrictions unique to a species environment. For my third Chapter I used a meta-analysis to reveal female preference experiments generally failed to present females with male display structure sizes informed by allometric data. This implies questions central to sexual allometry theory – that female preferences drive the evolution of disproportionately larger male sexual structures – are yet to be formally tested in an experimental setting. I designed such an experiment using realistic models of a terrestrial Blenniid fish species from Chapter two. Its findings indicate, in the absence of environmental constraints, female preferences can support the evolution of disproportionate scaling among sexual allometries. Finally, in Chapter four I expand upon my findings in Chapter two and explore additional ways the environment might restrict sexual allometric relationships. Specifically, its influence upon the visual efficacy of these structures…
author: Summers, Thomas ; https://orcid.org/0000-0002-8743-1545
language: en
keywords: sexual selection, allometry, mate choice, female assessment, ornaments, animal communication, anzsrc-for: 31 BIOLOGICAL SCIENCES, anzsrc-for: 310405 Evolutionary ecology, anzsrc-for: 310301 Behavioural ecology
license: https://purl.org/coar/access_right/c_abf2
license: https://creativecommons.org/licenses/by/4.0/
date published: 2021
date modified: 2026-07-24T05:32:00Z
provider: University of New South Wales
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: UNSW, Sydney

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1959.4/100225

PropertyValue
property ID: DOI
value: 10.26190/unsworks/23915