What Is Exponential Growth Biology?

Exponential growth is a biological principle that follows a format in which a population of life forms grows at a faster rate when the population is larger. Exponential growth assumes birth and death rates are constant, and factors such as migration are non-existent. The graph of an exponential growth system follows a continuous curve upward over time.

A simple example of exponential growth revolves around paramecia. Each of these one-celled creatures divides into two separate organism by simple mitosis. Assume that on "Day Zero" of the graph, there is a single paramecium, and the organisms multiply once per day. On "Day One," there are two paramecia. On "Day Two," there are four. On "Day Three," there are eight and so on.

The function of paramecium population growth is squared, or with the exponent of two. One squared is two. Two squared is four. Four squared is eight and upward until the graph appears to trend almost vertically. The paramecium population doubles every day in this simple example. The rate of population increase is faster as time moves forward. There are fewer organisms on "Day One" than on "Day 10," which means more organisms are created on "Day 11" than on "Day Two."

The journal "Nature" explains several formulas that describe exponential growth on a given day. Exponential formulas offer models for predicting population explosions, determining the economic limits of populations and figuring population density.