Did you know that lizards share similar sleep patterns with humans? Researchers with Germany’s Max Planck Institute for Brain Research have published a study in the journal Science that shows reptiles sharing similar sleep stages as us humans.
The researchers placed electrodes on the brain surfaces of five Bearded Dragons (one of the most popular lizards in the reptile hobby), and recorded evidence that the reptiles went through similar sleep patterns as that of humans, including slow wave sleep, sharp waves, ripples and rapid eye movement, or REM, according to CNN.
Until recently, CNN reports, scientists had only studied the sleep patterns of mammals and birds. Researchers used the Bearded Dragon in the study because it is the most distantly related reptile to birds. The study states that sleeping may have evolved from a common ancestor earlier than previously thought, dispelling the argument that REM and slow wave sleep cycles were the domain of more highly evolved animals.
One distinctive difference the researchers found was the way lizards sleep, specifically the location in the brain in which sleep stages took place. With the Bearded Dragon, the sleep stages occurred in a different part of the brain, the dorsal ventricular ridge, than where human sleep stages occur, in the hippocampus.
Gilles Laurent, the principal author of the study thinks that the area of the Bearded Dragon’s brain that triggers sleep could be more ancient and the origins of sleep may be traced earlier on the evolutionary tree, according to CNN.
While lizards share similar sleep patterns as humans, and go through rapid eye movement (REM) when sleeping, do lizards dream? Laurent told CNN that he is skeptical that lizards can dream in the same complex manner as humans, even though they share similar neural experiences. But he said “If you are ready to accept that bits of ‘neuronal playback’ in certain brain areas during sleep can be called dreams, then… I’ll bet that lizards dream.”