Author ORCID Identifier
https://orcid.org/0000-0002-2287-7650
Date of Award
Summer 8-8-2024
Document Type
Thesis (Ph.D.)
Department or Program
Ecology, Evolution, Environment and Society
First Advisor
Ryan Calsbeek
Second Advisor
Hannah ter Hofstede
Abstract
In animal communication, signal phenotypes are shaped by a combination of selective
forces pushing for improved transmission, efficiency, and detection, and limited by
developmental constraints in signal production and reception abilities (Morton 1975; Guilford &
Dawkins 1991; Endler 1992; Davranoglou et al. 2023). These opposing forces have resulted in
communication strategies that are broadly diverse yet similar among closely related species. We
expect to see gradual changes in signal phenotypes across different clades (Harvey & Pagel
1991). Sometimes, though, the communication strategies of closely related taxa are drastically
different (Ligon et al. 2018), indicating that selection must have overcome the strong inertial
forces of both sender signaling capability and receiver sensory physiology. This leads to the
question, how do novel signals emerge and change given the constraints of inherited sensory
systems and signal production mechanisms?
In field crickets (Family Gryllidae), males produce loud, low-frequency calling songs to
attract females. The songs are species specific, and females are attracted to the conspecific signal.
Male field crickets also produce songs in close-range contexts that influence female mating
decisions. Additionally, flying field crickets attend to the high-frequency sounds of approaching
bat predators and can steer away to avoid predation. Although the above behaviors are common to
most species, crickets in the tribe Lebinthini behave differently. Lebinthine males produce highfrequency
songs, females respond with a vibrational reply, and males search for the responding
female. How exactly this communication system evolved from the typical gryllid strategy
requires further inquiry.
In this dissertation, I examine how phylogenetic and morphological constraints affect
signal evolution in lebinthine crickets by addressing the following questions:
1: How have sensory precursors in ancestral crickets influenced the structure of the
lebinthine communication system?
2: How have novel lebinthine signals become informative despite constraints imposed by
evolutionary history?
3: How do the pressures affecting one type of signal in the cricket repertoire affect the
characteristics of other signals within the same animal?
The following work combines investigations of the ancestral origin, extant function, and
contemporary diversity of lebinthine signals to gain a holistic view of novel signal evolution.
Recommended Citation
Phillips, Mia E., "EXPLORING THE ROLES OF PHYSIOLOGY AND PHYLOGENY IN NOVEL SIGNAL EVOLUTION" (2024). Dartmouth College Ph.D Dissertations. 301.
https://digitalcommons.dartmouth.edu/dissertations/301
