Text 1
Some biologists argue that the primary evolutionary benefit of a zebra’s stripes is thermoregulation. According to this model, the alternate absorption of heat by dark stripes and reflection by light stripes creates micro-convective air currents across the zebra's body. These currents supposedly cool the animal, allowing it to forage in intense equatorial heat where non-striped equids might suffer heat stress. Proponents of this view point to variations in stripe definition across different geographical regions, noting that stripe patterns are often most distinct in the hottest areas of a zebra's range.
Text 2
Experimental studies by Tim Caro and colleagues suggest that zebra stripes serve primarily to deter biting insects. By placing striped blankets on horses, researchers observed that tabanid flies approached striped surfaces at normal speeds but failed to decelerate properly, often bumping into the animals or veering away without landing. Caro argues that because biting flies transmit fatal diseases, the selective pressure to avoid them is far more critical to survival than thermoregulatory efficiency. Furthermore, he notes that several non-striped equid species thrive in equally hot African environments without experiencing significant heat stress.
Based on the passages, how would the author of Text 2 most likely respond to the geographic evidence cited by the proponents of the thermoregulation hypothesis in Text 1?
- ABy proposing that zebras in cooler regions do not face significant threats from disease-carrying biting insects.
- BBy demonstrating that the micro-convective air currents generated by stripes are insufficient to deter biting flies.
- By arguing that the successful adaptation of non-striped equids in the same hot regions indicates that temperature variations do not necessitate stripes for survival.Answer
- DBy claiming that stripe patterns are uniform across all zebra populations regardless of local temperature variations.