Phylogenetics and Biogeography of Australian Biodiversity

Australia’s biota presents a complex tapestry woven from ancient Gondwanan roots, Miocene aridification and repeated climatic oscillations. Phylogenetic analyses, increasingly informed by high-throughput sequencing, reveal deep divergence among lineages that pre-date many continental radiations. Biogeographic studies identify key barriers such as the Bassian Isthmus and the Burdekin Gap, as well as mesic refugia in upland and rainforest zones, which have acted as sanctuaries during arid or glacial intervals. The interplay of vicariance and dispersal has driven both cryptic speciation and repeated biome shifts between monsoonal tropics, savannahs and arid interior. Recent advances in coalescent modelling and multilocus data have refined divergence-time estimates, while integrative approaches combining morphology, genomics and ecological niche modelling are reshaping species delimitations. These insights underpin conservation priorities, guiding the protection of evolutionary hotspots and informing predictions of biotic responses to ongoing climate change.

Research from Nature Portfolio

Recent studies have recovered archival DNA from museum specimens to resolve the true affinities of the largest known gecko, demonstrating unexpected links to New Caledonian clades rather than New Zealand, and revealing repeated convergence in toe-pad morphology across Pacific diplodactylids. Complementary phylogenomic work on Triodiinae, a dominant C4 grass lineage, has used relaxed molecular clocks to date diversification to the mid-Miocene aridification, showing that subsequent niche shifts into savannah accompanied convergent changes in leaf anatomy rather than key innovations driving initial colonisation.

Phylogenetics and Biogeography of Australian Biodiversity publication trend

The graph below shows the total number of articles in phylogenetics and biogeography of australian biodiversity across all publications each year (not limited to Nature Index journals).

Technical terms

Phylogenetics: Reconstruction of evolutionary relationships among species or populations using genetic or morphological data.

Biogeography: Study of the spatial distribution of species and ecosystems across geological timescales.

Phylogeography: Investigation of the geographical distribution of genetic lineages to infer historical demographic and dispersal events.

Molecular clock: Technique that estimates divergence times by correlating genetic mutations with elapsed time.

Refugium: Locale that provides environmental stability, allowing the persistence of lineages during adverse climatic periods.

ddRAD-seq: Genomic method sampling thousands of loci via double-digest restriction enzymes for population and phylogenetic analyses.

References

1. Reappraising the evolutionary history of the largest known gecko, the presumably extinct Hoplodactylus delcourti, via high-throughput sequencing of archival DNA. Scientific Reports (2023).
2. Key innovation or adaptive change? A test of leaf traits using Triodiinae in Australia. Scientific Reports (2015).
3. Long-term climatic stability drives accumulation and maintenance of divergent freshwater fish lineages in a temperate biodiversity hotspot. Heredity (2024).
4. Independent Transitions between Monsoonal and Arid Biomes Revealed by Systematic Revison of a Complex of Australian Geckos (Diplodactylus; Diplodactylidae). PLOS ONE (2014).