The rosy/communist* image of ants sacrificing personal success for the good of the colony has been dealt a hefty blow by a paper in this week’s PNAS. It seems it is not just human populations who are subsidising their queens…

Researchers have discovered that some ants appear to cheat the system by making their offspring more likely to become breeding queens, rather than have to endure the drudgery of a worker’s life.

“The accepted theory was that queens were produced solely by nurture: certain larvae were fed certain foods to prompt their development into queens and all larvae could have that opportunity,” says Bill Hughes of the University of Leeds (press release).

“But we carried out DNA fingerprinting on five colonies of leaf-cutting ants and discovered that the offspring of some fathers are more likely to become queens than others. These ants have a ‘royal’ gene or genes, giving them an unfair advantage and enabling them to cheat many of their altruistic sisters out of their chance to become a queen themselves.”

In fact fully 20% of leaf-cutting ant appeared to be cheating their nest-mates by making their offspring more likely to become queens. This is done in two ways: producing a generally larger adult and tweaking the switch that controls queen-worker development.

This ‘royal genotype’ is actually quite rare in the ant population, according to the paper (which should appear here shortly). “The rarity of the royal lines is actually an evolutionary strategy by the cheats to escape suppression by the altruistic masses that they exploit,” explains Hughes.

Hughes says most societies show conflict and cheating. “It was thought that ants were an exception,” he notes, “but our genetic analysis has shown that their society is also rife with corruption – and royal corruption at that!”

It seems a bit unfair to label this ‘cheating’. It’s not as if the ants are doing it consciously.

*(delete according to political viewpoint)

Image: Ant queen and worker / D.R. Nash