Final answer:
Logistic growth, also known as the S-shaped curve, is a realistic model of population growth. It starts with exponential growth, followed by a decrease in growth rate, and finally levels off at the carrying capacity. Examples of logistic growth include yeast, sheep, and harbor seals.
Step-by-step explanation:
Logistic growth, also known as the S-shaped curve, is a more realistic model of population growth compared to exponential growth. Initially, growth is exponential when resources are abundant. However, as resources become limited, the growth rate gradually decreases. Eventually, the population reaches its carrying capacity, resulting in little to no change in population size over time.
Examples of logistic growth include yeast in a test tube and wild populations such as sheep and harbor seals. These populations sometimes exceed the carrying capacity temporarily, causing fluctuations in population size around the equilibrium. Overall, the logistic model accurately describes population growth patterns.
The S-shaped curve is a graphical representation of logistic growth and can be seen in Figure 19.5b. It shows the three sections of the curve: exponential growth, decreasing growth rate, and a plateau at the carrying capacity.