Closeup of the head to Solenopsis geminata (fire ant)

Joint Evolution of Asexuality and Queen Number in an Ant

A recent paper in Current Biology by DeWayne Shoemaker and colleagues from the University of Georgia describes a socially polymorphic population of the tropical fire ant, Solenopsis geminata, in which multi-queen colonies produce queens asexually but produce workers sexually via matings with males from the sexually reproducing single-queen social form. Two distinct asexual lineages from multi-queen colonies likely originated from the same sexual single-queen population. Multiple asexual/polygyne genomes are transmitted undiluted in this system, but sterile workers produced with sperm from a sexually-reproducing/monogyne population are necessary for the persistence of these lineages. The intersection of social polymorphism, facultative asexuality, and genetic caste determination marks this population of S. geminata as an embodiment of the diversity of ant reproductive systems and suggests previously…