For decades, marine biologists have maintained that unihemispheric sleep—resting one half of the brain at a time—is an absolute requirement for all cetaceans to avoid drowning. It is true that this unique sleep pattern allows species like dolphins to continuously maintain the motor control needed to surface for air. The necessity of unihemispheric sleep for marine mammal survival has, nevertheless, been fundamentally overstated. Recent field observations of sperm whales demonstrate that they regularly engage in periods of profound, bihemispheric sleep. The ability of these whales to safely suspend respiration and motor function during deep, total rest proves that other physiological adaptations can adequately compensate for the absence of constant conscious awareness.
Which one of the following most accurately expresses the main conclusion of the argument?
- ACetaceans possess alternative physiological adaptations that can compensate for the temporary loss of conscious awareness during rest.
- The claim that marine mammals absolutely require unihemispheric sleep to survive is significantly exaggerated.Cevap
- CThe unique sleep pattern of resting one hemisphere of the brain at a time is an essential mechanism for cetaceans to avoid drowning.
- DField observations indicate that certain large whales are capable of engaging in profound, total-brain sleep.
- EMarine mammal species that currently rely on unihemispheric sleep will gradually develop the ability to safely suspend respiration during total rest.