Fruit flies prioritize sex over survival | biodiversity

You know those little flies that live on top of bananas in the kitchen? A study published this Wednesday (11) showed that fruit flies (Drosophila melanogaster) have a risky behavior when it comes to sex: they continue to have sex even when the partner, whether male or female, is infected with some deadly pathogen.

According to study author Carolina Rezaval of the University of Birmingham, the research was motivated by an interest in finding out how animals prioritize and balance their investment in species-perpetuating activities such as immune defense and reproduction, as “animals have limited energy resources that need to be distributed among different activities, such as fighting an infection or mating.”

The species studied has been used for more than a century for genetics and behavior research, including the courtship ritual that is “composed of complex innate behaviors that culminate in copulation”, the researchers tell the Daily Mail.

The experiment worked like this: in the laboratory, the flies were infected with bacteria such as Serratia marcescens e Staphylococcus aureus. After this step, males and females were placed in a ‘courtship chamber’ to see if they would mate. Scientists thought that infections could reduce the amount of energy available for activities such as mating, but courtship and copulation behaviors were similar in infected and uninfected flies.

And this happened despite the flies knowing they were sick, as previous studies have shown that infected fruit flies can exhibit abnormal locomotion, sleeping and eating behaviors.

The research also observed that, in addition to Drosophila melanogasters As sick people prioritize sex over conserving energy to fight infections, uninfected flies mated with both infected and healthy partners, suggesting that they do not shy away from choosing sick partners who can contaminate them.

The new study, published in the Proceedings of the Royal Society B, suggests that mating prioritization may be related to the fact that when faced with a potential threat to life, some animals respond by investing more in reproduction, likely in an attempt to pass the genes on to the next generation, a theory that should be further investigated in further research.