Chapter 5, Problem 1TYC

To determine

The type of feedback loop that is more common in nature, and that results from human action. Also describe the way in which the emergence of a positive feedback loop affects a system in homeostasis.

Answer to Problem 1TYC

The most common type of loop in nature is negative feedback loop and is the results of human action while the positive feedback loop only sometimes results from human action. Negative loop is able to resist the changes in system as it enhances its stability to the outer condition. In positive feedback loops the system takes away itself to the extreme condition. It leads to destabilization of the system.

Explanation of Solution

A system includes all the elements and compounds that are interlinked with each other. They all affect one another through the interchange of energy, matter and information. Environment is just like a system which takes energy, matter and other sources as an input, and process that to generate output.

Feedback loop includes a circular pathway in which system output act as input for the same system. There are two types of feedback loop: positive feedback loop and negative feedback loop.

Positive feedback loop is more common in nature, and are results of human action. This loop drives extra output from a system, which leads to increase in input demand, leading to further enhanced output, and so on.

Exponential growth of a population is the best illustration of this feedback loop. The more is the individual, the more offspring produced. Positive feedback loops that are generated due to human impact can destabilize the natural system.

For example, in the Chesapeake Bay, water is cleaned by oysters through trickling phytoplankton, sediments, and nutrients from the column. When oyster population is declined due to overharvesting, water filtration also diminishes. This causes elevation in the levels of phytoplankton. When phytoplankton die they accumulated in the bay bottom and are decomposed by bacteria. As a results the oxygen in the water get depleted and this condition is known as hypoxia. This results in death of the oysters which are remaining.

Homeostasis refers to a system which is able to maintain its internal condition at a constant and stable way. Homeostatic system experiences the change itself slowly over time. Positive feedback facilitates destabilizing effect that decreases the stability of the system to resist a change. It forces the organisms to adapt to the system normal conditions and often harms them.