Data from: Metabolism and the rise of fungus cultivation by ants

Most ant colonies are comprised of workers that cooperate to harvest
resources and feed developing larvae. Around 50 million years ago (MYA),
ants of the attine lineage adopted an alternative strategy, harvesting
resources used as compost to produce fungal gardens. While fungus
cultivation is considered a major breakthrough in ant evolution, the
associated ecological consequences remain poorly understood. Here, we
compare the energetics of attine colony-farms and ancestral
hunter-gatherer colonies using metabolic scaling principles within a
phylogenetic context. We find two major energetic transitions. First, the
earliest lower-attine farmers transitioned to lower mass-specific
metabolic rates while shifting significant fractions of biomass from ant
tissue to fungus gardens. Second, a transition 20 MYA to specialized
cultivars in the higher-attine clade was associated with increased colony
metabolism (without changes in garden fungal content) and with metabolic
scaling nearly identical to hypometry observed in hunter-gatherer ants,
although only the hunter-gatherer slope was distinguishable from isometry.
Based on these evolutionary transitions, we propose that shifting
living-tissue storage from ants to fungal mutualists provided energetic
storage advantages contributing to attine diversification and outline
critical assumptions that, when tested, will help link metabolism, farming
efficiency, and colony fitness.