An ant species native to the South American region has completely eliminated males from its population. Mycocepurus smithii, a fungus-gardening ant, reproduces without any males whatsoever, and has been doing it for millions of years.
Science Daily reports:
"Animals that are completely asexual are relatively rare, which makes this is a very interesting ant," says [Christian] Rabeling, an ecology, evolution and behavior graduate student at The University of Texas at Austin. "Asexual species don't mix their genes through recombination, so you expect harmful mutations to accumulate over time and for the species to go extinct more quickly than others. They don't generally persist for very long over evolutionary time."
This species appears to have been around for 2 million years, which is relatively short compared to the 50 million years its fellow fungus-farming ant species have been around. Rabeling also dissected the Mycocepurus smithii queens, and discovered their sperm storage vessels are empty, so it isn't as if they've produced a few males, gotten inseminated, and then killed them off quickly.
Technically these ants reproduce asexually, not through some kind of Nicola Griffith-style lesbian parthenogenesis. They are, however, one of the only known all-female animal species. Who is to say whether it wasn't some lesbian urge that caused them to diverge from other ant species and give up sperm altogether?
Rabeling says that more research is needed to determine exactly how these ants are maintaining genetic diversity, and when they diverged from similar species.
via Science Daily
(Thanks for the tip, Roklimber!)