Populating a Continent: Phylogenomics Reveal the Timing of Australian Frog Diversification

Abstract

The Australian continent’s size and isolation make it an ideal place for studying the accumulation and evolution of biodiversity. Long separated from the ancient supercontinent Gondwana, most of Australia’s plants and animals are unique and endemic, including the continent’s frogs. Australian frogs comprise a remarkable ecological and morphological diversity categorized into a small number of distantly related radiations. We present a phylogenomic hypothesis based on an exon-capture dataset that spans the main clades of Australian myobatrachoid, pelodryadid hyloid, and microhylid frogs. Our time-calibrated phylogenomic-scale phylogeny identifies great disparity in the relative ages of these groups which vary from Gondwanan relics to recent immigrants from Asia and include arguably the continent’s oldest living vertebrate radiation. This age stratification provides insight into the colonization of⁠, and diversification on, the Australian continent through deep time, during periods of dramatic climatic and community changes. Contemporary Australian frog diversity highlights the adaptive capacity of anurans, particularly in response to heat and aridity, and explains why they are one of the continent’s most visible faunas.

Multi-omics resources for the Australian southern stuttering frog (Mixophyes australis) reveal assorted antimicrobial peptides

“…Additionally, they are the first ‘omics level resources in the Mixophyes genus. As the Myobatrachidae family is one of the oldest, most diverse frog families in Australia 40 , these resources add to our understanding of Australian fauna.…”

“…The number of known cathelicidins and β-defensins across the Anuran order is limited, with only one cathelicidin characterised in a European frog, and no known cathelicidins or β-defensins from South American frog species. As the Myobatrachidae family shares a distant common ancestor with South American frogs 40 , evolutionary relationships within AMP families across these geographical regions are likely not captured. As more frog cathelicidins and β-defensins are characterised, in particular from Australia and South America, future investigations may better identify the evolutionary patterns of AMP diversity across Mixophyes and other frogs.…”

“…A genomics-driven approach has been applied to discover novel AMPs from a range of non-model species 35 , 37 – 39 . However, despite the evolutionary divergence of Australian frog families (Limnodynastidae and Myobatrachidae diverged from South American frogs an estimated 80–100 million years ago) 40 , 41 , none have yet been investigated for AMPs using a bioinformatic approach.…”

Multi-omics resources for the Australian southern stuttering frog (Mixophyes australis) reveal assorted antimicrobial peptides

“…Additionally, they are the first ‘omics level resources in the Mixophyes genus. As the Myobatrachidae family is one of the oldest, most diverse frog families in Australia (Brennan et al 2023), these resources add to our understanding of Australian fauna.…”

There and back again: when and how the world's richest snake family (Dipsadidae) dispersed and speciated across the Neotropical region

“…We furthermore compared the above models with the added +j parameter, which allows founder-event speciation and was added due to its potential importance in reconstructing insular historical biogeography (Klaus & Matzke, 2020;Matzke, 2022;but see Ree & Sanmartín, 2018). To each model we also added a time-stratified matrix with dispersal probabilities (Data S2) between pairs of areas specified based on geological events occurring in each period (Figure 1b), varying between 0.1 (unlikely), 0.5 (probable) and 1 (likely), similarly to other studies on the historical biogeography of large clades (e.g., Australian frogs; Brennan et al, 2023). For this matrix, we considered potentially relevant events (Figure 1b (Matzke, 2013).…”