A groundbreaking discovery has unveiled a remarkable reproductive strategy in Iberian harvester ants (Messor ibericus), challenging our understanding of basic biology. Researchers have found that these queens can produce eggs that develop into two distinct ant species: their own and a hybrid with the closely related Messor structor. This astonishing revelation emerged from an investigation into the unexpected presence of Messor ibericus ants on the Italian island of Sicily, thousands of kilometers from the nearest known Messor structor populations.
Initially, scientists suspected hybridization. However, five years of extensive research, involving genomic sequencing of hundreds of ants across Europe and laboratory experiments, revealed a far more extraordinary truth. Iberian harvester queens can manipulate their reproduction, producing eggs that develop into either pure Messor ibericus or hybrid worker ants, primarily Messor structor, which constitute 99% of the colony.
This unusual reproductive method, termed xenoparity, involves the queen cloning the genetic material of Messor structor males from stored sperm, effectively deleting her own nuclear DNA in the process. The resulting offspring are nearly identical to their Messor structor fathers, a process described as sexual domestication, never before witnessed in the animal kingdom. This evolutionary adaptation likely arose from an earlier reliance on Messor structor males for reproduction, a strategy now superseded by complete genomic control by the queen.
The study highlights a unique evolutionary path. Millions of years ago, Messor ibericus and Messor structor diverged, but despite geographical separation, Messor ibericus queens maintained the ability to reproduce with Messor structor males, initially through mating and later through cloning their sperm. This cloning eliminates the need for geographical proximity and has enabled the establishment of widespread invasive hybrid colonies throughout the Mediterranean.
The implications of this discovery are profound. The Iberian harvester ant represents a novel mode of reproduction, shedding light on the potential for cross-species cloning. The detailed understanding of this natural cloning process could inspire new approaches to artificial cloning in other species. While further research is needed to fully comprehend the precise mechanisms involved, this exceptional finding transforms our understanding of ant reproductive strategies and the remarkable adaptability of life in the face of evolutionary pressures. The unique competitive advantage of producing fitter hybrid workers allowed Messor ibericus to thrive, despite its unusual reproductive dependence, underscoring the powerful forces of natural selection.
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Originally published at: https://edition.cnn.com/2025/09/13/science/iberian-harvester-ants-two-species
