12 Biology - Unit 3.1

Exponential Growth Pattern:

An exponential growth pattern (J curve) occurs in an ideal, unlimited environment.

• Under ideal conditions with unlimited resources, a population will growth exponentially.

• Exponential growth does not happen in natural populations for very long because the resources get used up.

• Population growth slows down when food and space become more difficult to find (competition).

J curves are most commonly seen with r-strategist species.

Logistic Growth Pattern (S Curve)

• A logistic growth pattern (S curve) occurs when environmental pressures slow the rate of growth.

• When populations grow exponentially but begin to slow when resources are used up.

• As the growth curve slows down and flattens out, it is said that the population has reached its carrying capacity