Scientists discover ‘supergene’ alters social structure of red fire ant colonies | Science and technology news
Scientists have identified a new “social supergene” that is spreading between different species of fire ants and is reorganizing their societies.
Researchers at Queen Mary University of London were “incredibly surprised” to see the new form of social organization taking over colonies in the wild.
Notorious for their painful stings and aggressive colony tactics, red fire ants have been known to attack and kill small animals.
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It is native to South America but is considered an invasive pest in the US, Australia and Taiwan – where it has proven incredibly difficult to eradicate, earning the species its Latin name Solenopsis invicta, meaning “the invincible one”.
Originally, red fire ant colonies had just one queen, but researchers uncovered genetic changes that occurred nearly a million years ago where colonies could have dozens of queens.
New research, published in the journal Nature Communications, analyzed the entire genomes of 365 male fire ants to examine the evolution of this gene – and found that it spreads across multiple fire ant species.
Species are usually defined as independent because they cannot breed and exchange genetic information, but there are rare instances where fertile hybrids can be created. In this case, researchers believe that the benefits to the colonies of having multiple queens have overridden any genetic incompatibilities, meaning “the genetic material is replicated from the one source species in which this new social form evolved, in other ways.”
dr Yannick Wurm of Queen Mary University said: “This research shows how evolutionary innovations can spread across species. It also shows how evolution works at the level of DNA and chromosomes.
“It was incredibly surprising to discover that other species could acquire a new form of social organization through hybridization.
“The supergene region that gives rise to multi-queen colonies is a large piece of chromosome containing hundreds of genes. The many parts of a genome evolve to work together in finely tuned ways, and so all of a sudden you get a mix of different versions of many genes—another species is complicated and quite rare.”
dr Wurm added: “Rather than executing extra queens like a single-queen colony would, the new version of the supergene causes workers to accept multiple queens.
“Having extensively studied the history of the supergene and the new social form, we next want to find out which genes or parts of the supergene region lead to these behavioral changes. This will also help fill further gaps in our understanding of evolutionary processes.”
Rodrigo Pracana, a lead author on the study, also at QMU, said: “Our study shows how detailed analysis of a large number of wild animals can provide surprising new insights into how evolution works.”