Male and female fire ants keep their gene pools separate by cloning themselves -- an unheard of genetic isolation of the sexes that may revise evolutionary rules, scientists reported this week in the journal Nature.
In an accompanying commentary, David Queller, a biologist at Rice University in Houston, wrote that male and female fire ants might represent two distinct species, rather than one.
Biologists analyzed DNA from the stinging insect Wasmannia auropunctata, commonly called the little fire ant. The ants were collected from nests found rolled up in leaves among the rain forests and coffee plantations of French Guiana on South America's Caribbean coast.
Some of the queens' eggs developed without male fertilization. These produced only females that shared identical genes with queens.
In the cutthroat world of evolutionary survival, this allows queens to promote 100% of their DNA to the next generation, rather than having half combined with male DNA.