Evolutionary drivers of biological invasion: insights from economically and environmentally important insect groups (Coleoptera: Bostrichidae and Ptinidae)
Phylogenomics of Australian darkling beetles
Darkling beetles (Coleoptera: Tenebrionidae) are hyper-diverse. With over 20,000 species worldwide, they rank the seventh largest beetle family with enormous morphological diversity. Despite of this, dedicated molecular phylogenies of darkling beetles are scarce and most deep relationships in the family remain unresolved. The uniqueness of Australian tenebrionid fauna has been well documented at different evolutionary depths. It was thought to comprise a mix of relict lineages, which have been present on the continent since it was part of Gondwana in the Mesozoic, and ‘invasive’ elements, which were derived from Asian lineages in the last 20 Myr by successive waves of colonization. In this study, I will generate anchored hybrid enrichment datasets to establish a backbone phylogeny for Australian darkling beetles. By reconstructing their evolutionary histories, I will explore macroevolutionary trends across space and through time, and test which processes have driven their diversification.
Adaptive radiation across the continent
With over 500 species, the Gondwanan lineage of darkling beetles, Heleini, was considered by Eric Matthews as a potential example of adaptive radiation. They are hypothesized to have radiated on the Australian continent during the time that it was isolated, evolved into diverse body forms and filled into a variety of ecological niches. This project aims to test the adaptive radiation hypothesis of Heleine darkling beetles with robust phylogenetic and ecomorphological datasets and within a statistical framework. Specifically, I will test a number of characteristics regarding the tempo and mode of adaptive radiation by (i) examining diversification rates through time and across biomes (ii) investigating rates of morphological diversification to determine ecological opportunities that have contributed diversification rate shift and (iii) assessing the strength of convergence in body shape/leg morphology between distantly related lineages that occupy the same habitat.
Diversification in the Wet Tropics
On a regional scale, I will look at the Wet Tropics of Queensland, the largest remnant of Gondwanan rainforest in Australia. These isolated mountain blocks of rainforests, with high species richness and endemicity, provide an excellent template to study diversification, coexistence and persistence of lineages at multiple levels of divergence. I will focus on the flightless darkling beetle genus Apterotheca, with about 50 species restricted on mountain peaks in this region. These beetles are geographically restricted and rich in species diversity, thus have the potential to yield a fine-scale record of deep-time processes in the Wet Tropics. Species limits and the first phylogenetic hypothesis were established by Bouchard (2002) based on morphology. Also, analyses of multiple clades of flightless insects supported the ‘taxon pulse’ model as the main process that shaped regional species pools (Bouchard et al. 2005). By combining distribution and morphology with molecular phylogenies, I’ll revisit these questions and generalize these results with published vertebrate data.