Only a tiny difference separates docile workers from those that can dethrone a queen.
Each new bee is a perfect clone of herself. When they hatch, the rapidly reproducing clones can take wing and raven through the countryside in search of other subspecies’ hives, where they invade hapless victims’ nests, lay their own eggs, and act as parasites until the host colony collapses. But by then, other copies of the insubordinate worker have been born and flown over the horizon in search of new queens to dethrone.
In a bee, this is monstrously strange. Generally, colonies of bees and other social insects function like a single superorganism, with the many supporting the reproduction of the few. They are all so closely related that this amounts to helping themselves. When a Cape honeybee transforms from a placid social insect into a parasite, it’s doing something that appears outside the natural order. Ever since people discovered parasitic Cape honeybees inside collapsing colonies in South Africa, about a hundred years ago, beekeepers and biologists have considered: How does this happen? In a new paper out in Molecular Biology and Evolution, biologists provide the beginnings of an explanation, revealing that a single blip in the genetic code is the only difference between these bees and their peaceful siblings.
Perhaps this ability, odd as it seems, has been beneficial for Cape honeybees in the evolutionary past. The researchers observed that the bees’ natural habitat is quite windy, and the ability of a worker to transform herself into a kind of queen might save colonies when their queens are blown off course and lost during mating flights. That single genetic change and the hormonal storm it must unleash might have meant the difference between total obliteration and bouncing back from a loss. Rather than a perversion, it might represent a kind of awe-inspiring, if slightly terrifying, flexibility in the face of disaster.