|Bearded dragon image modified from Morguefile / cooee|
Dragons sleep, and they probably even dream. Though this could likely be said of Smaug the Magnificent sleeping for centuries atop his golden hoard in Tolkien’s Lonely Mountain of Hobbit fame, scientists have now shown that the Australian bearded dragon, popular as a pet worldwide, has sleep cycles analogous to those in cats, birds, and everyone reading this article. And since dreams happen during our REM sleep, it is not unreasonable to imagine that lizards truly embark on their own dream quests while their eyes twitch.You can finish reading by clicking on "Have Evolutionists Found the Root of REM Sleep?"
To Sleep, Perchance to Dream
All sorts of animals sleep, even the lowly roundworm. And sleep is important. A fruit fly has a tough time learning and remembering simple lessons—like how to avoid bitter smells and nasty shocks—when deprived of sleep. But not all animals have sleep like ours, characterized by alternating cycles of distinctive electrical activity in the brain. Until now, it was thought that only mammals and birds experienced REM and non-REM sleep. The discovery of these alternating sleep patterns in lizards suggests, according to the authors of “Slow Waves, Sharp Waves, Ripples, and REM in Sleeping Dragons,” that these complex sleep cycles evolved at least 320 million years ago in animals distantly ancestral to all mammals, reptiles, and birds.
Human beings spend a lot of time sleeping, and disturbance of our normal sleep cycles is associated with many problems from poor productivity to psychological issues. Each phase of sleep is characterized by particular electrical patterns produced by the neurons in the brain. REM sleep is associated with high frequency electrical activity. Non-REM sleep is also called slow wave sleep because it is associated with slower, low frequency electrical activity.