Who Dreams

We still do not know the exact evolutionary purpose to dreaming- if there even is one. Yet, it never fails to baffle me that somehow, dreaming is such a big part of humans and most other animals. I don't have a pet -apparently my plant does not count- but most pets can be seen dreaming. I would pay millions of nonexistent money to understand the cause or even contents of these dreams.

You might think that animals dream differently than us because their brains function differently. However, MIT research Wilson proved that rats dream exactly like us- in stages and about their experiences. Like us, rats go through multiple stages of sleep, to REM sleep. About half of the dreams repeated the unique signature of brain activity that was created as the rat ran, leading to the conclusion that they dreamed of running. Sure the content of the dream might be simpler, but the function and the process is exactly the same.

Similarly, dogs, cats, ducks, platypuses, even sloths dream. Think about how many dreams sloths have, sleeping 2/3 of their lives away. Almost all animals and birds dream. Even ants experience REM stage, where their antennas move rapidly, suggesting the occurrence of a dream. It might be more beneficial to look at what animals don't dream, perhaps then it will be clearer as to why almost all mammals have the function of dreaming.

Only some insects and fish don't experience the REM stage. Why is that the case, though? Perhaps, it's because fish sleep with their eyes open and the entire action is a trance-like daydream. When fish sleep, they never completely lose consciousness; this is most likely due to the fact that they are never truly safe enough to completely sleep. Their brains sleep in shifts, resting different systems at different times. Shutting down nonessential bodily functions for periods of time- like day dreaming. So it can be easy to realize that it was to their evolutionary advantage that fish do no dream. Then how is dreaming an advantage to the success of most mammals?