Data and code from: Tempo and mode of morphological evolution in Australian and New Guinea diving beetles from underground waters to alpine peat swamps
Data files
Sep 30, 2026 version files 2.33 MB
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all_merged_Adrian_and_triplets.TPS
684.61 KB
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Combined_matrix_pruned_withHPD.nexus
634.80 KB
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Modified-Combined_matrix_100best_all_GTR_lognormal.tre
851.78 KB
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README.md
2.14 KB
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TempoMode.R
107.23 KB
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Triplets_and_AdrianSpecies-George_naming_system.csv
47.32 KB
Abstract
Transitions into novel environments expose species to altered biotic and abiotic selection pressures, promoting phenotypic diversification and the emergence of distinct ecological niches. While adaptive selection often drives phenotypic change, non-adaptive processes, including relaxed selection and genetic drift, may also contribute to morphological evolution. Over the past c.10 million years, Australian and New Guinea diving beetles (Limbodessus, Dytiscidae) have repeatedly diversified across three contrasting environments: above-ground in lowland-montane waters and high-elevation habitats, and below-ground in groundwater aquifers. These recurrent habitat transitions serve as natural "evolutionary experiments" for investigating different selection pressures. Using a phylogenetic comparative approach, we examined the tempo and mode of Limbodessus body-shape evolution to distinguish between adaptive and relaxed selection across ecotypes. Lowland-montane dytiscids exhibit convergent evolution and slow morphological rates of evolution, consistent with stabilising selection maintaining streamlined forms. Subterranean species present high morphological disparity and diffuse morphospace occupation, suggesting relaxed or neutral evolution. High-elevation species show rapid morphological evolution into novel morphospace regions, suggesting strong selection pressures distinct from those in lowland environments. Together, our findings emphasise the importance of relaxed selection and neutral processes in shaping phenotypic variability during ecological transitions.
Dataset DOI: 10.5061/dryad.nvx0k6f5j
Data and code for Limbodessus body shape evolution
This dataset accompanies the paper “Tempo and mode of morphological evolution in Australian and New Guinea Diving Beetles from underground waters to high elevation peat swamps” in Evolution. It contains 2D body-outline landmarks data, phylogenetic trees, labelling metadata, and R codes.
- all_merged_Adrian_and_triplets.TPS — Two-dimensional body-outline landmark coordinates obtained using tpsDIG2. The landmark scheme includes 10 fixed landmarks and 61 semi-landmarks per specimen.
- Triplets_and_AdrianSpecies-George_naming_system.csv — Metadata of the labelling system for specimens and species.
- Combined_matrix_pruned_withHPD.nexus — Pruned phylogenetic tree in NEXUS format, with highest posterior density (HPD) information.
- Modified-Combined_matrix_100best_all_GTR_lognormal.tre — Phylogenetic tree in .tre format. This is a Bayesian time-calibrated phylogeny of 105 diving beetle taxa.
- TempoMode.R — R script for the geometric morphometrics and phylogenetic comparative analyses used in the manuscript.
Columns in the CSV metadata file
Each row represents a specimen record.
Column Size was not used in this study. The habitat includes epi (epigean or surface dwelling), sub (subterranean), int (interstitial), and alp (alpine or high elevation). specimen_source records the source used in the label (SAMA = South Australian Museum, Adrian = Co-author Adrian Villastrigo's specimen/image series, and DRAW = landmark data digitised from drawings in published taxonomy papers). locality and GPS contains the locality data.
Empty cells and non-data columns
Empty cells in the named columns mean that the relevant information was not entered or was unavailable in this metadata table. For instance, some specimens have no locality info.