Polygamous mice 'have more fertile offspring'

Washington, Feb 04 (ANI): A new study in mice has suggested that multiple partners may be the key to agile sperm that get the job done.

Researchers Renee Firman and Leigh Simmons at the University of Western Australia found that after only 12 generations, mice brought up in a polygamous mating group developed stronger and faster sperm and had better mating success than their monogamous counterparts, reports Live Science.

When looking at sperm competition in mice, "males evolving with sperm competition (polygamy) had a significant paternity bias over males evolving without sperm competition (monogamy)," the researchers said.

So those mice with multiple mates, over several generations, were more likely to father children than the monogamous males, the first time this has been seen in vertebrates.

Researchers created the mice by preferentially breeding them in either polygamous relationships or monogamous relationships for several generations.

After eight generations they noticed that the sperm of the polygamous mice were stronger and faster than the sperm from monogamous mice.

"In the eighth generation, we observed genetic divergence in ejaculate quality; males evolving under sperm competition had higher sperm numbers and better sperm motility compared to males with a selection history of monogamy," the researchers write.

The study has been published in the journal BMC Evolutionary Biology. (ANI)