Using Genomic and Plumage Data to Understand Contemporary and Historical Relationships among Australian Rosellas (Genus: Platycercus)

View/ Open
Author(s)
Primary Supervisor
Hughes, Jane
Other Supervisors
Schmidt, Daniel
Year published
2017
Metadata
Show full item recordAbstract
It is now widely understood that species boundaries are often semipermeable, and that hybridisation and introgression occur frequently in nature and have the potential to dramatically alter the evolutionary trajectory of the taxa involved. Hybrid zones, regions where genetically distinct populations overlap and produce hybrid offspring, provide a valuable opportunity to gain insight into the speciation process. They can arise without a period of isolation when distributions span environmental gradients or ecotones
(primary hybrid zone), or as a result of secondary contact following allopatric divergence (secondary hybrid ...
View more >It is now widely understood that species boundaries are often semipermeable, and that hybridisation and introgression occur frequently in nature and have the potential to dramatically alter the evolutionary trajectory of the taxa involved. Hybrid zones, regions where genetically distinct populations overlap and produce hybrid offspring, provide a valuable opportunity to gain insight into the speciation process. They can arise without a period of isolation when distributions span environmental gradients or ecotones (primary hybrid zone), or as a result of secondary contact following allopatric divergence (secondary hybrid zone), and their structure and ultimate evolutionary outcome can vary greatly depending on the strength of pre- and post-mating barriers to gene flow, as well as the impact of other evolutionary forces (e.g. selection). The dawn of the age of genomics offers great possibility for the analysis of potentially hybridising taxa. In this thesis, I employ a genomic approach alongside more traditional molecular and non-molecular techniques to examine the presence and influence of hybridisation on two native Australian parrot species, the pale-headed (Platycercus adscitus) and eastern rosellas (P. eximius). Together, these species, which are each composed of readily identifiable subspecies, span the eastern seaboard of Australia, with species and subspecies reportedly hybridising where their ranges overlap.
View less >
View more >It is now widely understood that species boundaries are often semipermeable, and that hybridisation and introgression occur frequently in nature and have the potential to dramatically alter the evolutionary trajectory of the taxa involved. Hybrid zones, regions where genetically distinct populations overlap and produce hybrid offspring, provide a valuable opportunity to gain insight into the speciation process. They can arise without a period of isolation when distributions span environmental gradients or ecotones (primary hybrid zone), or as a result of secondary contact following allopatric divergence (secondary hybrid zone), and their structure and ultimate evolutionary outcome can vary greatly depending on the strength of pre- and post-mating barriers to gene flow, as well as the impact of other evolutionary forces (e.g. selection). The dawn of the age of genomics offers great possibility for the analysis of potentially hybridising taxa. In this thesis, I employ a genomic approach alongside more traditional molecular and non-molecular techniques to examine the presence and influence of hybridisation on two native Australian parrot species, the pale-headed (Platycercus adscitus) and eastern rosellas (P. eximius). Together, these species, which are each composed of readily identifiable subspecies, span the eastern seaboard of Australia, with species and subspecies reportedly hybridising where their ranges overlap.
View less >
Thesis Type
Thesis (PhD Doctorate)
Degree Program
Doctor of Philosophy (PhD)
School
Griffith School of Environment
Copyright Statement
The author owns the copyright in this thesis, unless stated otherwise.
Subject
Pale-headed parrot (Platycercus adscitus)
Eastern rosellas (P. eximius)
Species boundaries
Hybridisation
Introgression of species
Plumage data, Parrots
Genomic data, Parrots