ANT MENACE DOES NOT STOP!!

Evolution of supercolonies: the Argentine ants of southern Europe. 

Giraud T, Pedersen JS, Keller L.

Abstract

Some ants have an extraordinary social organization, called unicoloniality, whereby individuals mix freely among physically separated nests. This type of social organization is not only a key attribute responsible for the ecological domination of these ants, but also an evolutionary paradox and a potential problem for kin selection theory because relatedness between nest mates is effectively zero. The introduction of the Argentine ant in Europe was apparently accompanied by a dramatic loss of inter-nest aggression and the formation of two immense supercolonies (which effectively are two unicolonial populations). Introduced populations experienced only limited loss of genetic diversity at neutral markers, indicating that the breakdown of recognition ability is unlikely to be merely due to a genetic bottleneck. Rather, we suggest that a "genetic cleansing" of recognition cues occurred after introduction. Indeed workers of the same supercolony are never aggressive to each other despite the large geographical distance and considerable genetic differentiation between sampling sites. By contrast, aggression is invariably extremely high between the two supercolonies, indicating that they have become fixed for different recognition alleles. The main supercolony, which ranges over 6,000 km from Italy to the Spanish Atlantic coast, effectively forms the largest cooperative unit ever recorded.

Proc Natl Acad Sci U S A. 2002 Apr 30;99(9):6075-9. Epub 2002 Apr 16.

Why is this cool?

 Have you ever seen the Outer Limits Sand Kings episode? It is about space insects and their CONQUEST OF EARTH!! Whenever I think about colony/hive/herds/friendship I instinctively imagine a battle for global dominance. Ants really put the scare on me, because once or twice I have mindlessly stood on an ant pile, only to find them crawling up my legs! I would swat and jump and shriek like a little girl...a European girl, but there would always be one that finds its way behind my ear to bite me.

 Today's paper is about the major victory that Antdom has had over mankind on the European front. I have not read the paper, but it seems that the researchers compared parts of the ant genome that had previously been shown to be important in recognition. They found that within supercolonies, the sequences they were looking at were the same across the area of the supercolony! Rival supercolonies most likely have different recognition sequences and this leads to battle.
 If each supercolony learned how to trade and manage an economy, they might be able to band together to obliterate the vineyards of Europe and really crush the human stain!
Something interesting that I noticed from abstract is that the supercolony that stretches from Italy to Spain is described as being the largest cooperative unit, but what about humans? Don't our civilizations span many thousands of miles and don't we cooperate to a large degree?