1. Population Growth Chapter 11
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2. Geometric Growth Nt = Noλt
When generations do not overlap, growth can be modeled geometrically.
Nt = Noλt
Nt =
No =
λ (lambda) =
t =

3. Exponential Growth dN / dt = rmax N
Continuous population growth in an unlimited environment can be modeled exponentially.
dN / dt = rmax N
dN =
dt =
rmax =
N =
______________________

4. Exponential Growth dN / dt = rmax N
Appropriate for populations with overlapping generations.
As population size (N) increases, rate of population increase (dN/dt) gets larger.
Which variable above would best represent the “Intrinsic rate of increase”?

5. Exponential Growth Nt = Noermaxt
For an exponentially growing population, size at any time can be calculated as:
Nt = Noermaxt
Nt =
N0 =
e = Base of natural logarithms.
rmax = Per capita rate of increase.
t = Number of time intervals.

6. Exponential Population Growth

7. Logistic Population Growth

8. Logistic Population Growth
As resources are depleted, population growth rate slows and eventually stops:
Sigmoid (S-shaped) _______________________
___________________ is the number of individuals of a population the environment can support.
Finite amount of resources can only support a finite number of individuals.

9. Logistic Population Growth

10. Limits to Population Growth
Environment limits population growth by altering …
Density-dependent factors?!?
Density-independent factors?!?