S-shaped curve

Definition

An S-shaped curve, or sigmoid curve, represents logistic growth where a population's size stabilizes after a period of exponential growth. This pattern occurs when environmental limits, such as resources and space, eventually restrict further growth.

5 Must Know Facts For Your Next Test

1. The S-shaped curve depicts three phases: lag phase, exponential growth phase, and stationary phase.
2. During the exponential growth phase, the population grows rapidly due to abundant resources.
3. In the stationary phase, population growth slows and stabilizes due to limiting factors like food scarcity or space constraints.
4. The carrying capacity is the maximum population size that an environment can support sustainably, represented by the plateau of the S-shaped curve.
5. This model contrasts with the J-shaped curve, which represents unchecked exponential growth without environmental limits.

Review Questions

Related terms

Carrying Capacity:

The maximum number of individuals that an environment can sustain indefinitely without degrading.

Exponential Growth:

A pattern of population increase where the number of individuals grows at a constant rate per time period.

Limiting Factors:

Environmental conditions that limit the growth, abundance, or distribution of a population within an ecosystem.