Zombies, the plague and pestilence of mankind. If there was one creature with the ability to steal our rightful place at the top of the food chain it would be zombies. No other creature throughout all of recorded history has had the ability to capture our imagination and cause as much raw terror as zombies. From biblical times to now, zombies have loomed an ever growing and horrid shadow over our heads.

Throughout the ages zombies have appeared in many different forms from the mummies of Egypt to the viral outbreaks in such famous present day titles as 28 Days Later, zombies have always played an important role in culture. No matter what form they appear in the threat is still the same. Their infection is spread from person to person claiming countless souls turning man against himself and turning brother against brother.

Zombies are defined simply as the “living dead”, a seemingly dead body that by some means has been reanimated. The term has also been used as a way to describe someone who seems to drone on and is seemingly lifeless in their activities, for example, “Are you going to sit in front of the TV like a zombie all day?”

Below we will discus a zombie’s physiology. It is important to note that these are generalizations based on currently accessible data, and educated guesses. The information contained in this article is subject to change at any moment as more zombie research becomes available.

	A Zombie Biting

The life cycle of a zombie is fairly simple and easy to understand. First the initial infection agent (i.e. virus, bacteria, toxin, etc.) finds a host. Once infected, the host will fall ill, and eventually lapse into a coma. The duration of the coma can last anywhere from just a few minutes to several hours. The entire metamorphosis from time of infection to becoming a zombie typically does not last more than 24 hours.

Zombies can not reproduce by traditional means. Zombies are completely sterile. Since the human reproduction system is not essential to the functioning of the brain, it is shut off and rendered useless instantly. Zombies, instead, reproduce by infecting other healthy human beings with their “zombie causing agent” via direct fluid transfer typically through a bite to the flesh.

Once a human turns into a zombie, the body begins to decay instantly with the immune system. The lifespan of a zombie is estimated to be as long as 4 years, but is often much shorter. This varies greatly, depending on a number of factors including relative climate, physical damage sustained, age, size, weight, etc.

Zombies do not require any nourishment to survive. It is still not known why they feed on human flesh. They also do not require air, and have no use for any organs with the exception of the brain.

Zombies can only be “killed” by direct trauma to the brain as this is their only vital organ. Once a limb is severed from the body, the limb will cease to function. A decapitated zombie’s body will as well cease to function. However, the head with brain intact will still attempt to attack passersby.

Once a zombie is terminated, it still poses a threat to non-infected humans, as tissue and bodily fluids still contain infectious material. Thus, corpses should be properly disposed of.

	Human Muscle Structure

Zombies are not superhuman. They are bound to all the same earthly laws and physical traits that define the person they once were. For example, a blind man who becomes infected will produce a blind zombie; a particularly weak person will result in a particularly weak zombie. The thing that sets us apart from zombies is their inability to feel. This refers to both feeling in mental form (i.e., emotions), and physical form (i.e. pain). Because zombies are without feeling, they are able to push themselves much harder than the average person, far beyond what we would consider to be “the breaking point”.

If you were trying to move a heavy object obstructing your path, you would begin to exert force on that object in the hopes of moving it. If the object were too heavy, you would be forced to stop due to fatigue or physical injury. These feeling of fatigue and injury are not felt by zombies however. If a zombie were to attempt to move the same heavy object out of its way, it would continue to due so until either the object was moved, or it was rendered physically incapable of moving the object. Very often zombies are seen with injuries such as dislocated joints, broken bones, and severe muscle or tissue damage. This is usually the result of the zombie attempting to perform feats beyond what its’s body is capable of. Without the benefit of a working immune system, or regeneration of any kind, the injuries that a zombie sustains (both self-inflicted or otherwise) are permanent, and will last until the zombie expires. So, a zombie’s greatest advantage over us may possibly be their biggest disadvantage.

Zombies possess the same physical abilities we all possess as human beings. One tends to wonder why they are so incapable of running, or dodging and block incoming attacks. The correct answer is that they possess the ABILITY to perform these tasks, but lack the coordination required to PROPERLY execute those tasks. We take walking for granted. A lot goes into each step we take. From your foot to your head there are literally hundreds of subtle muscle movements. Balance and terrain are also taken into account, along with dozens of other factors. All this information is calculated instantaneously by our brains, and we take a step. This information is poorly calculated by a zombie’s vastly more simple brain, thus rendering them unable to properly balance or take steps in rapid succession (e.g., running) giving them a more “shuffle” like appearance to their movement. For these same reasons, zombies are completely incapable or jumping or balancing on a narrow surface. They also tend to be poor at side stepping, and backing up, which typically ends with them falling to the ground. Zombies are also unable to swim, and can only float for a short period of time before becoming water logged and sinking to the bottom, they can however remain intact at the bottom of a body of water for a fairly long period of time before ceasing to function.