The order Fucales (i.e., fucoids) contains many of the dominant habitat-forming seaweeds of Australian coastal ecosystems, including species of Sargassum, Cystophora, Scytothalia, and Platythalia. These species form extensive underwater forests that support biodiversity, productivity and ecosystem functioning across tropical and temperate Australia. Despite their ecological importance, the evolutionary history of Australian fucoids remains poorly understood, particularly within the highly diverse family Sargassaceae, which contains several lineages largely restricted to Australasia.
Recent advances in long-read sequencing now provide unprecedented opportunities to reconstruct evolutionary relationships using complete nuclear and organellar genomes. Supported by a major national genomics initiative, this PhD project will generate and analyse genomic datasets to resolve the evolutionary history of Australian fucoids, investigate the origins of endemic Australasian lineages, and examine how habitat-forming species may respond to ongoing environmental change. The project will combine comparative genomics, phylogenomics, historical biogeography and population genomics to address fundamental questions about the evolution and future resilience of one of Australia’s most important groups of marine foundation species.
Aim
The overall aim of the project is to understand the evolutionary origins, diversification and adaptive capacity of Australia’s habitat-forming fucoid seaweeds using genome-scale datasets.
Objectives
- The first objective is to resolve the phylogenetic relationships between Australian fucoid seaweeds. The project will generate and analyse nuclear, mitochondrial and plastid genomic datasets to reconstruct evolutionary relationships among Australia’s major fucoid lineages. Moreover, the project will integrate newly generated Australian genomes with publicly available global datasets to develop the most comprehensive phylogenomic framework to date for the order Fucales.
- Using genome-scale phylogenies, this project will test hypotheses regarding the origins and diversification of endemic Australasian lineages, including Cystophora, Scytothalia and Platythalia. The project will examine whether Australasia acted as an evolutionary centre of origin for these groups and investigate how major geological and climatic events have shaped contemporary diversity patterns. Comparative analyses will be used to reconstruct the evolution of key morphological and ecological traits across the Fucales.
- Third, this project will asses genomic diversity and adaptive potential in species experiencing range shifts. Applying whole-genome resequencing and/or reduced-representation approaches (e.g., DArTSeq), the student will investigate population structure, connectivity and environmental adaptation in selected habitat-forming species. Particular emphasis will be places on species undergoing climate-driven changes in distribution or abundance, providing insights into the evolutionary processes that may facilitate persistence under future ocean warming.
Significance
Australia supports one of the world’s most distinctive and diverse assemblages of fucoid seaweeds, yet many aspects of their evolutionary history remain unresolved. In particular, the origins and diversification of endemic Australasian Sargassaceae represent one of the major outstanding questions in seaweed evolution and biogeography. This project will generate a transformative genomic resource for Australian marine biodiversity while addressing fundamental questions regarding speciation, dispersal, trait evolution and adaptation. By integrating phylogenomics with population genomics, the project will provide both deep-time and contemporary perspectives on the processes shaping biodiversity in marine foundation species.
The research is also highly relevant to conservation and climate adaptation. Many fucoid seaweeds are experiencing shifts in distribution associated with ocean warming, yet little is known about their capacity for adaptation or the evolutionary significance of populations across their ranges. Outcomes will help inform conservation priorities, restoration planning and biodiversity monitoring while establishing a genomic framework that will support future research on marine forests throughout Australasia.
Ideal Candidate
We seek a highly motivated PhD applicant with a background in marine biology, evolutionary biology, genetics, bioinformatics or a related discipline. An interest in evolution, biodiversity and genomic approaches to understanding ecological and evolutionary processes is essential. Experience with molecular biology, phylogenetics, bioinformatics, population genetics, R programming or Linux-based computing would be advantageous but is not required, as training will be provided. The successful applicant should be enthusiastic about developing quantitative and computational skills, working within a collaborative national research network, and applying genomic approaches to address questions in evolution, biogeography and climate change biology. Additionally, the applicants should meet the eligibility criteria for entry into a PhD program at Curtin University.
This project is open to International and Domestic applicants.
Scholarship
If you are identified as the preferred candidate for this project, you may be considered for an RTP scholarship.
Enquires and How to Apply
For enquires about this opportunity contact Dr Sam Starko at Sam.Starko@curtin.edu.au
To formally apply submit an Expression of Interest to Dr Sam Starko during the Central Scholarship round (July 1st – July 31st 2026)