Complex sentence: This hypothesis does not explain the muscle paralysis of REM sleep; however, a logical analysis might suggest that the muscle paralysis exists to prevent the animal from fully waking up unnecessarily, and allowing it to return easily to deeper sleep.
Split into simpler sentences: This hypothesis does not explain the muscle paralysis of REM sleep. Although a logical analysis might suggest that the muscle paralysis exists to prevent the "awakening" animal for waking up unnecessarily and allowing it to return easily to deeper sleep.