Female Fruit Flies 'Get Busy' Staying Alive

Thank those swinging lady fruit flies for keeping the male fruit fly population alive. 

Researchers from the University of Liverpool found that when female flies mate with several partners, it helps them reduce the occurrence of an X chromosome that can lead to the production of only female offspring.

In fact, researchers discovered that what's known as selfish genetic element (SGE) works to replicate itself by killing sperm that carry the Y chromosome. Of course, a detrimental side effect to this element is that males carrying the gene may produce fewer sperm. Yet when female fruit flies work to mate with several partners in order to increase the probability of reproducing SGE-free males with higher sperm counts, it solves the problem.

As previous studies have shown that southern populations of this insect carry a higher prevalence of the gene compared to northern counterparts, it's hypothesized that northern flies are just more experimental.

Unfortunately, findings were grim when more-chaste options were concerned. In fact, research showed that when females were only allowed to mate once, this SGE gene spread rapidly and increased the extinction of populations in as little as nine generations.

"If this particular SGE was to spread to every male in a population, then no more males would be born, and the population, or even the whole species, would become extinct," said evolutionary biologist Dr. Tom Price from the University of Liverpool's Institute of Integrative Biology, via a press release.

Price concludes with the importance of frequent mating for the safety of the species.

"There are a large number of these SGE genes in many organisms, which selfishly increase their own success while damaging the health of individuals and the species as a whole, but in this case the flies have developed mechanisms to limit their impact," he said, via the release. "Females with a high sex drive and males with a high sperm count are keeping this species going."

More information regarding the findings can be seen via the Proceedings of the Royal Society.