The expression “Men need women more than women need men” may hold even truer for a species of ants, which have no male counterparts, discovered by ecologists from Brazil and the University of Texas.
Biology professor Ulrich Mueller and Christian Rabeling, an ecology, evolution and behavior graduate student, discovered Mycocepurus smithii, which is the first known species of ant that has no males and reproduces asexually. Species that reproduce asexually are very rare, making this an incredible find, Rabeling said.
For the most part, social insects, including bees, ants and termites, don’t rely on males but instead have a dominant egg-laying queen that presides over large numbers of infertile females who carry on the daily tasks of the colony. But even these insects produce male counterparts to continue the fertilization and reproduction of their species.
“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,” Rabeling said.
Mueller said this particular ant differs from that norm.
“This ant species, however, has had no trouble reproducing and is able to grow successfully in lab conditions,” Mueller said.
The ants, which reside in Northern Mexico, Central America and Brazil, underwent several tests, including changing their fungal food source — which also happened to be asexual — to see if there was any change in the reproduction of the ants. Researchers also dissected the reproductive organs to see if there were any trace amounts of sperm.
Both tests support the idea that the ants are purely asexual.
Even though there are few species of insects that reproduce asexually, there are some advantages to reproducing this way, said lead researcher Anna Himler, who works at the University of Arizona. Reproducing “asexually avoids the energetic cost of producing males, and thus doubles the number of reproductive females produced each generation from 50 percent to 100 percent of offspring,” she said
“By reproducing this way, this species of ants doesn’t rely on a mating season and queens can produce fertile offspring to go and form their own colonies as they please,” Rabeling said.
Scientists predict that these ants evolved not too long ago, and further tests are being conducted by Rabeling and his peers to deduce the time period that these ants appeared.
Currently, the focus is on determining whether the ants use meiosis or not. By finding this, scientists will know whether all the ants produced are exact clones or some recombination took place and small differences exist within the population.