"An Amazonian ant has dispensed with sex and developed into an all-female species, researchers have found.
The ants reproduce via cloning - the queen ants copy themselves to produce genetically identical daughters.
This species - the first ever to be shown to reproduce entirely without sex - cultivates a garden of fungus, which also reproduces asexually.
The finding of the ants' "world without sex" is published in the journal Proceedings of the Royal Society B.
Anna Himler, the biologist from the University of Arizona who led the research, told BBC News that the team used a battery of tests to verify their findings.
Unusual evolution
By "fingerprinting" DNA of the ant species - Mycocepurus smithii - they found them all to be clones of the colony's queen.
And when they dissected the female insects, they found them to be physically incapable of mating, as an essential part of their reproductive system known as the "mussel organ" had degenerated.
This species has evolved its own unusual mode of reproduction
Anna Himler
University of Arizona
Asexual reproduction of males from unfertilised eggs is a normal part of some insect reproduction, but asexual reproduction of females is "exceedingly rare in ants", wrote the researchers.
"In social insects, there are a number of different types of reproduction," explained Dr Himler. "But this species has evolved its own unusual mode."
She and her colleagues do not know exactly why this particular species has become fully asexual, and how long ago the phenomenon evolved."
http://news.bbc.co.uk/1/hi/sci/tech/7998931.stm
