In order to decide if a given system is living, it must be compared to a basic definition of life. If a system passes all of the criteria defined, it can be called a biotic system. Three basic systems, the Rainbow Grasshopper, Avian Influenza A (H5N1) Virus, and the Internet, will be examined to determine if they are biotic or abiotic.
To decide if these systems are living, they will be compared to a definition of life as given by Capra. Capra’s definition states that in order for a system to be alive it must exhibit the following properties, it must be continually reproducing or self-making, it must take in foods for energy and expel waste, and it must have the ability to sense and respond to its environment. If a system displays all of these properties it is considered to be a living, biotic organism. (Bird, lecture 1)
The Rainbow Grasshopper is a biotic organism based off of Capra’s definition of life. During fall, female grasshoppers lay eggs destined to hatch in the following spring. (GC, par. 2) It also takes in food in the form of plant debris and insect material and expels wastes after digestion. (GC, par. 19) Lastly, the grasshopper is capable of sensing its environment and responding, according to Grasshoppers of Colorado, “grasshopper flights terminate when temperature decreases or the sun is obscured by clouds.” (GC, par. 17) Because the grasshopper satisfies these conditions, it can be concluded they are living organisms.
The next system to be investigated is the Avian Influenza A Virus. By definition this virus is not a living organism because it fails to meet the last two conditions of the definition. The virus is composed of RNA strands wrapped in a protective protein coating and therefore does not require food for energy. (Bird, lecture 3) It is fully capable of reproducing after it enters a host cell and sheds its protein shell. Because it is composed mainly of RNA, it contains no nervous system or any other means of sensing its environment. The virus is not a living system because it only meets one of the three conditions set by Capra’s definition of life.
The Internet will be the last system examined to determine if it is a living system. The Internet is a system of wiring that allows multiple computers to communicate throughout the world. The internet is not capable of reproducing by itself; it may only expand as other computers are connected to it. Second, the internet requires no direct form of food to survive, only computers are required. Lastly, the internet is not capable of sensing its environment. It has been setup to work a specific way regardless of environment.
By comparing these organisms to the definition of life, it can be concluded that only the Rainbow Grasshopper satisfies all three conditions and therefore is the only biotic system. The Avian Influenza A Virus and the Internet are abiotic because they failed one or more of the conditions in the definition. Any system can be compared to this definition to decide if it is a living organism.
Grasshoppers of Colorado. “Grasshopper Biology.” Sept. 6, 2005
Bird, George. ENT205 Class Lectures, Michigan State University 07