Within recent decades, several species of ants from around the world have developed a radical expression of social organization that is unparalleled by any other known biological association, and defies simple scientific explanation. These organizations are known as supercolonies, and they can consist of millions of genetically unrelated ant colonies which function as a single, massive co-operative unit. The largest of these supercolonies spans over six thousand kilometers and is located in Europe, along the Mediterranean coast. Billions of individual ants inhabit coastal areas from Northern Italy to Portugal, and collectively they form the largest biological organization ever known on Earth.
Modern paleontologists speculate that colonial behavior in ants and bees appeared about 40 to 60 million years ago. Since that time, colonial insects have functioned as extended families working as single hives, defending against enemies which often included rival colonies of the same species. Why this behavior evolved is still a mystery, but even greater is the enigma of supercolonial emergence.
Originally, the ants from the European supercolony lived in Argentina, and fought fiercely among rival colonies. It was first thought that supercolonial behavior resulted from the introduction of a single queen to an environment with little or no competitive organisms. When the supercolonial ants were studied, it was revealed that there was great diversity among the co-operating ants; the supercolony consisted of many unrelated families that acted as though they had lost their ability to recognize enemy colonies. Then scientists discovered a second supercolony in the Catalonia region of Spain, and these ants would fight to the death with members of the main European supercolony. It seemed that the ability to fight was not forgotten after all. In fact, the supercolony had eliminated 90% of competitive species in the areas it occupied. This meant that a simple genetic explanation for supercolonial behavior did not exist. What caused this dramatic change in modality?
Supercolonial behavior has now been expressed by at least three ant species from around the world. Argentine ants have supercolonies in Europe, Australia, and in the United States of America. On the Japanese island of Hokkaido, red wood ant have been supercolonially active for over thirty years, and on Christmas Island in the Pacific, yellow crazy ants have destroyed almost half of the sensitive jungle environment that is home to the red land crab, now a threatened species.
The ants that established the largest supercolony were believed to have arrived in container ships carrying plants from Argentina to Europe. The ants quickly adapted to the favorable Mediterranean environment, reproducing rapidly and unchecked by typical ant predators. Could conditions in the Lower Mainland allow for the establishment of an ant supercolony? Ample shipping and a suitable environment point to this being a very real possibility.
Trilobites at False Creek
6 years ago