How do brain chemicals influence who wins a fight?
Researchers tested the effects of serotonin on aggression in stalk-eyed flies, predicting that increasing the brain serotonin in a stalkeyed fly would make it more likely to use aggressive behaviors, and flies that used more aggressive behaviors would be more likely to win.
How to escape a predator
Natural selection may select against the stalk-eyed flies' long eyestalks, causing males with more elaborate traits to be predated more. Perhaps the behavior of the fly is more important than the length of the eyestalk when faced with a predator. Researchers tested whether differences in eye span and/or antipredator behavior were important for survival in stalk-eyed flies.
The flight of the stalk-eyed fly
Male stalk-eyed flies have longer eyestalks than females, and this plays an important role in the flies’ mating patterns. However, natural selection likely acts against the exagerration of these ornaments. Scientists measured the effect of eyestalk length on the moment of inertia of the body and measured differences in turning performance during flight.
