Describe what logistic growth is and how it relates to carrying capacity.
The correct answer and explanation is:
Correct Answer:
Logistic growth is a model of population growth that starts with a slow increase, followed by a rapid exponential growth phase, and finally slows down as the population approaches a maximum limit called the carrying capacity. Carrying capacity is the maximum number of individuals that an environment can sustainably support due to limitations such as resources, space, and other environmental factors.
Explanation:
Logistic growth describes how populations grow in natural environments where resources are limited. Initially, when the population size is small, growth occurs rapidly because there are abundant resources and little competition. This phase is similar to exponential growth where the population increases at a constant rate over time.
As the population size increases, resources such as food, water, and living space become scarcer. Increased competition and other environmental pressures slow down the growth rate. This deceleration continues until the population size stabilizes around a certain limit known as the carrying capacity.
The carrying capacity represents the maximum population size that an environment can support indefinitely without degrading the resources. If the population exceeds this limit, resource depletion, disease, and other stress factors typically cause the population to decline back toward the carrying capacity level.
The logistic growth curve typically forms an S-shaped or sigmoid curve when population size is plotted against time. The initial phase is slow growth, the middle phase is rapid growth, and the final phase is a plateau as the population nears carrying capacity.
This model is important for understanding real-world population dynamics because it incorporates environmental limits, unlike simple exponential growth models that assume unlimited resources. Logistic growth applies to many biological populations and helps ecologists and resource managers predict how populations will respond to changing conditions and resource availability.