Scientists at Rockefeller University have detailed a surprising discovery about clonal ants, revealing lines of mutation that alter behavior and physiology within colonies. In the species Ooceraea biroi, researchers observed ants that do not contribute to work because of genetic changes, yet still parasitize their peers in the same colony or in nearby colonies. The study adds to a growing body of evidence about how genetic variation can shape social roles in colonies that reproduce without a queen. The findings were published in Current Biology, highlighting how mutation-driven differences can ripple through colony dynamics and individual life histories.
A notable observation is the emergence of a uterus-like trait in a subset of ants within this clonal population. Ooceraea biroi typically reproduces asexually, producing successive generations without a queen’s oversight. This reproductive mode makes the colony highly uniform, but the new mutation appears to disrupt this uniformity by modifying reproductive and developmental pathways. The observed changes trace back to a large-scale genetic region often referred to as a super gene, which coordinates the activity of more than 200 genes involved in hormone metabolism and signaling. When this region mutates, it can give rise to insects with wings, enlarged eyes, and functional ovaries, effectively altering their developmental trajectory and social role within the colony.
The consequence of such a mutation is a shift in reproductive strategy. These mutants tend to reproduce at a higher rate than their non-mutant counterparts, effectively doubling their reproductive pace. Despite this increased fecundity, the colony maintains control over population size. If there are insufficient workers to fulfill the roles expected of queens, some of the mutant individuals may die during the pupal stage, serving as a natural counterbalance to prevent overpopulation and maintain colony stability. This dynamic shows how natural selection can operate at both the level of the individual and the group, especially in colonies that rely on asexual reproduction and tightly coordinated social organization.
Researchers note that such mutations are not limited to J narrow genetic lines within a single species. Similar genetic and developmental shifts could arise in other ant species under natural conditions, suggesting that these traits might appear repeatedly in different lineages. The researchers propose that, over time, some of these winged, ovary-bearing mutants could become distinct enough to form a separate species, given enough genetic divergence and ecological separation. This possibility underscores how rapid genetic change can influence taxonomy and evolution in social insects, particularly in species where colony structure is highly plastic and driven by genetic and environmental interactions.
The study emphasizes that ant colonies are more genetically diverse than previously thought, even when colonies appear uniform due to clonal reproduction. The presence of hybridized dynamics—mutants parasitizing normal workers, varying rates of reproduction, and the potential emergence of new species—illustrates the complex interplay between genetics, development, and behavior in social insects. Researchers expect that further work will map the precise genetic pathways that connect the super gene region to hormonal changes, wing development, and reproductive capacity. Such work could illuminate how identical genomes can give rise to different life histories within the same colony and reveal the triggers that prompt transitions from normal worker roles to mutant, reproductive phenotypes. In the broader picture, these findings point to a remarkable flexibility in ant social systems and suggest that evolution can operate swiftly when a single genetic shift affects multiple physiological and behavioral traits. (Attribution: Rockefeller University, current research published in Current Biology.)