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There's more than one explanation for how colony-living animals like bees evolve their unique social structure, according to a detailed genome analysis conducted by Karen Kapheim and colleagues. Bees are eusocial, meaning that some of their workers forego reproduction to care for their siblings. In some cases, this can lead to an elaborate and sophisticated "superorganism" of thousands of individuals. Kapheim and colleagues took a detailed look at the genomes of ten bee species to determine if the evolution of eusociality always follows the same genetic road map. The answer, according to the researchers, is no: different genes and different gene networks have been involved each time that eusociality evolved independently among the bees. However, the bee species share some general trends related to this unique type of social evolution, including increases in the capacity for gene regulation and expression, and a higher complexity of gene networks. The researchers also found evidence that natural selection of certain key genes is relaxed after a species develops the most complex forms of eusociality, as is the case with honeybees.
Article #16: "Genomic signatures of evolutionary transitions from solitary to group living," by K.M. Kapheim at University of Illinois at Urbana-Champaign in Urbana, IL, and colleagues. For a complete list of authors, see the manuscript.