The evolution of cheaper workers facilitated larger societies and accelerated diversification in ants
Authors/Creators
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1.
University of Cambridge
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2.
Okinawa Institute of Science and Technology Graduate University
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3.
University of Hong Kong
- 4. Museum für Naturkunde
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5.
Karlsruhe Institute of Technology
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6.
University of Maryland
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7.
Okinawa Institute of Science and Technology
Description
Supplementary material related to the manuscript: "The evolution of cheaper workers facilitated larger societies and accelerated diversification in ants".
Python scripts. Automated segmentation and data extraction scripts for processing 3D µ-CT scans.
R scripts. Statistical and phylogenetic comparative analysis scripts used in this study.
Dataset S1. Extracted cuticle and body volume measurements for all scanned specimens.
Dataset S2. Manually segmented cuticle and body volume measurements for validation of the automated segmentation method.
Dataset S3. Colony size data.
Dataset S4. Presence of cuticular spines on the mesosoma at the genus level.
Dataset S5. Climatic data, including mean annual temperature and precipitation from species distribution records.
Dataset S6. Dietary classification of species and genus into four ecological categories: predator, omnivore, herbivore, and fungivore.
Dataset S7. Foraging strata classification including hypogeic, arboreal and epigeic strategies at the genus level.
Segmentation results. Segmented images generated by our program for automatic segmentation.
Abstract (English)
Trade-offs between quantity and quality are common in the organization and evolution of biological, technological, and economic systems. In social insects, shifts from solitary organisms to complex societies bring this dilemma to the colony scale: producing fewer robust units or many cheaper ones. We investigate how cuticle investment—a major nutritional cost—shaped the evolution of ant societies and diversification. Using a computer vision approach on 3D X-ray microtomography scans of 880 specimens from 507 species, we show that larger colonies were facilitated by reducing exoskeleton investment rather than miniaturizing workers. Reduced cuticle investment was associated with accelerated diversification rates in ants, whereas other candidates—colony size and worker size—didn’t correlate with diversification. Diet and climate had measurable but secondary effects on cuticle investment. Our results support a hypothesis whereby evolving cheaper but more numerous units through reduced investment in structural tissues was a strategic trend in the evolution and diversification of complex insect societies.