Researchers have made a fascinating discovery about Iberian harvester ants. These ants have a unique way of reproducing that challenges what we thought we knew about biology: Their queens can lay eggs that become two different species of ants.
The research began when scientists were puzzled by the disappearance of a certain ant species. They looked closely at the Iberian harvester ants, or Messor ibericus, especially a population found in Sicily. This group was producing hybrid worker ants from a distant relative, Messor structor, found over 600 miles away.
Jonathan Romiguier, a researcher at the University of Montpellier in France, explained the surprise in their findings. “We had a strong suspicion something was off, but we never imagined it was this unusual,” he said.
After examining over 120 ant populations across Europe for five years, the team found a truly bizarre reproductive method. One queen could produce both hairy and virtually hairless ants from her eggs, depending on the colony’s needs. If more queens were needed, eggs would develop into Messor ibericus; if more workers were required, they would become hybrids.
This discovery is reshaping our understanding of ant reproduction. Instead of being limited to their species, these ants can now create offspring from another species within their life cycle.
Jessica Purcell, an assistant professor of entomology at UC Riverside, has studied these ants in Italy. She noted that harvester ants forage for seeds and return them to their nests, often creating clearings around their homes.
Interestingly, both Messor ibericus and Messor structor were once one species before splitting approximately 5 million years ago. Researchers suspect that hats off to evolution, Messor ibericus queens have lost the ability to create their own worker ants. They’ve adapted by mating with Messor structor and producing hybrid workers.
Romiguier suggests that an evolutionary conflict led to this change. A genetic element might be pushing larvae to develop into queens to ensure its continued transmission to future generations. This means that to survive, Messor ibericus now relies on Messor structor for reproductive success.
This leads to another critical discovery: rather than simply using sperm from Messor structor, Iberian harvester ants have learned to clone these males. This phenomenon, called sexual domestication, has never been observed in any other animal.
Romiguier explains, “They gained control over the males they once exploited, much like how humans domesticate livestock.” As a result, Messor ibericus can maintain a lineage of cloned males without needing to be close to another species. This has allowed them to spread across the Mediterranean, leading to millions of hybrid worker ants.
The process involves what scientists are now calling xenoparity, which means these ants can propagate another species’ genes using their own eggs. This is groundbreaking and shows new evolutionary paths not previously accounted for.
By sequencing ant genomes, researchers identified that only the queens and males are pure Messor ibericus. Other fertilized eggs result in hybrid workers. The queens can even manipulate the genetic material they carry, extracting just the male genetic information needed.
Still, there’s a lot more to learn. What exactly causes the queens to clone their males? How do they manage to delete their own DNA? Understanding this could provide insights into cloning processes in other species.
Experts like Dr. Jacobus J. Boomsma from the University of Copenhagen, who wasn’t involved in the study, emphasize that these adaptations are likely driven by natural selection. The ability to create robust hybrid workers gives Messor ibericus a competitive edge in expanding their habitat.
In conclusion, this groundbreaking research is reshaping the field of entomology. As scientists delve deeper, the Iberian harvester ant may hold more mysterious strategies waiting to be uncovered.
For more about this study, you can read the full research published in Nature.
