Argumentative Essay: The Need For Sleep

The Need for Sleep

Though many may not often think about why we sleep, most of us know that sleep makes us feel better, it refreshes the body and makes it better able to function following a good night of sleep. However, the fact that sleep makes us feel better and that going without sleep makes us feel worse only begins to explain why we need sleep.

Another way to think about the need for sleep is to compare it to another of our needs, eating. Hunger is a protective alarm that has evolved to ensure that we consume the proteins, fats carbohydrates and calories our bodies require to grow, repair, and function correctly. And while it is easy to understand the role that eating serves, eating and sleeping aren’t as different as they may seem.

Both eating and sleeping are controlled by strong urges or sensations that we feel when they are required. Sleepiness obviously for sleep, and hunger for eating. And just as eating removes hunger and makes sure that we obtain the proteins, vitamins, fats and carbohydrates we need, sleeping removes the feeling of tiredness and gives the rest we feel we require. But the question is, why do

we require this sleep? Is there a primary function, or does sleep serve multiple functions?
Scientists have studied the question of why we sleep from many different angles. They have looked at what happens when humans or other animals are deprived of sleep. In other studies, they have looked at sleep patterns in a variety of organisms to see if similarities or differences among animals might reveal something about sleep's different functions. Yet, despite decades of research and many discoveries about sleep, the question of why we sleep still has yet to be clearly answered.
The lack of a clear answer to this question does not mean that this research has been a waste of time, we now know considerably more about the function of sleep, and scientists have made several good theories to explain why we sleep. But also, due to how promising many of these theories are, scientists are beginning to believe that the answer will involve many of these theories and not just one.
One of the earliest theories of sleep, sometimes called the adaptive or evolutionary theory, explains that inactivity at night is an adaptation that served as a survival function by keeping animals out of harm’s way at times when they would be particularly in danger. The theory suggests that animals that were able to stay still and quiet during these periods of vulnerability had an advantage over other animals that remained active. This has inspired some evolutionary theories of sleep. One theory is that animals who are lower in the food chain sleep less - because they are more vulnerable to attack. However, a conflicting theory suggests that sleep protects us from predators, since we are curled up in a quiet place out of harm's way. These animals did not have accidents during activities in the dark, for example, and were not killed by predators. Through natural selection, this strategy may have evolved to become what we now know as sleep “Sleep, then, is an evolutionary "escape" mechanism and not a "recuperative" one. David Marshall Mooney (2007-08-09)
A good argument to this theory is that it is always safer to remain awake in order to be able to react to and emergency, like a predator, where there really isn’t a known advantage in being unconscious and can easily be seen as a disadvantage.

Another theory for why we sleep is based on the belief that sleep in some way serves to restore what is lost in the body while we are awake. Sleep provides an opportunity for the body to repair itself. In recent years, these ideas have gained support from evidence collected in human and animal studies. One of these studies have shown that animals deprived entirely of sleep lose all immune function and die in just a matter of weeks. This is further supported by findings that many of the major restorative functions in the body like muscle growth and repair, as well as bone growth mostly happen during

sleep.
One of the most recent and well-founded explanations for why we sleep is based on findings that sleep is connected to changes in the structure and organization of the brain. This phenomenon, known as brain plasticity (Hebb, D. Konorski, J (1949 book The Organization of Behavior), is not entirely understood, but its connection to sleep has several critical implications. It is becoming clear, for example, that sleep plays a critical role in brain development in infants and young children. Infants spend about 13 to 14 hours per day sleeping, and about half of that time is spent in REM sleep, the stage in which most dreams occur. A link between sleep and brain plasticity is becoming clear in adults as well. This is seen in the effect that sleep and sleep deprivation have on people's ability to learn and perform a variety of tasks.
Another theory, the Energy Conservation Theory, suggests that the primary function of sleep is to reduce an animal’s energy demand and use during part of the day or night, especially at times when it is least effective in finding food, like at night.
Research has shown that energy metabolism is significantly reduced during sleep by as much as 10 percent in humans and even more in other species. For example, both body temperature and calories demanded decrease during sleep, as compared to wakefulness. Evidence supports the idea that one of the primary functions of sleep is to help animals reserve their energy resources. Many scientists consider this theory to be related to, and part of, the inactivity theory.
Although these theories remain unproven, science has made tremendous strides in finding out what happens during sleep and what urges and sensations in the body control the cycles of sleep and wakefulness that help define our lives. While this research does not directly answer the question, "Why do we sleep?" it does set the stage for putting that question in a new context and generating new knowledge about this essential part of life.