Soru

For decades, evolutionary biologists hypothesized that the primary function of zebra stripes was to provide camouflage against large predators in the African savannah. However, recent experimental studies have challenged this traditional view. To test alternative hypotheses, researchers set up several life-sized model horses in an open field, painting some with realistic black-and-white stripes and others with uniform dark or light colors. Over several weeks, they monitored the activity of biting flies, which carry lethal blood-borne diseases common in the region. The researchers observed that these flies landed on the striped models far less frequently than on the solid-colored models. A detailed analysis of fly flight paths revealed that the high-contrast stripes disrupt the flies' visual systems during their final approach, causing them to fail to decelerate properly or abort their landing attempts entirely. Consequently, the study concludes that zebra stripes evolved primarily as a physical defense mechanism against parasitic insects rather than as visual camouflage against apex predators.

Which of the following findings from the experiment described in the passage best supports the researchers' conclusion that zebra stripes evolved primarily as a defense against parasitic insects?