Global distribution of polymorphism in ants

Biologists have long been fascinated by the processes that give rise to the phenotypic complexity of organisms, yet whether there exist geographic hotspots of phenotypic complexity remains poorly explored. Phenotypic complexity can be readily observed in ant colonies, which are superorganisms with morphologically differentiated queen and worker castes analogous to the germline and soma of multicellular organisms. Several ant species have evolved ‘worker polymorphism’, where workers in a single colony show quantifiable differences in size and head-to-body scaling. Here, we use 256,754 occurrence points from 8,990 ant species to investigate the geography of worker polymorphism. We show that arid regions of the world are the hotspots of superorganism complexity. Tropical savannas and deserts, which are typically species-poor relative to tropical or even temperate forests, harbor the highest densities of polymorphic ants. We discuss the possible adaptive advant..., We reviewed the literature and classified 15,518 species of ants as either 'polymorphic’ according to a broad definition of worker polymorphism or as ‘monomorphic’ (Table S1, S2). Species lacking significant size or allometric variation in the worker caste were classified as monomorphic whereas all others were classified as polymorphic (see Fig. S1 for more details). To classify ant species as polymorphic or monomorphic, we first systematically searched AntWiki [34] and AntWeb [35], two open-access repositories curated by myrmecologists that collate information and list studies on each ant species, for relevant literature. These databases were chosen because resources are easily accessible and the taxonomic upkeep of the species pages is consistent [34, 35]. Using the primary literature cited on these pages, we searched for explicit mention of the terms monomorphic, polymorphic, or any of the categories of polymorphism defined by Wilson [21]. When multiple sources were available for a g..., , , # Global distribution of polymorphism in ants

Dataset DOI: [10.5061/dryad.nk98sf7v3](https://doi.org/10.5061/dryad.nk98sf7v3)

## Description of the data and file structure

# **Warm and arid regions of the world are hotspots of superorganism complexity**

## Description

This dataset contains georeferenced occurrence records for the global ant species derived from the GABI (Global Ant Biodiversity Informatics) database and enriched with spatial, biogeographic, and climatic covariates. Each row represents a unique occurrence record, including geographic coordinates, taxonomic classification, spatial aggregation identifiers, point density metrics, and climate variables extracted at the occurrence location.

The dataset is intended for use in biodiversity analyses, species distribution modeling, macroecology, and biogeographic synthesis.

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#### File: polymorphism_data_final.csv

## Data structure

Each row corresponds to a point occurrence record. Columns are described below.

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