1. 7.6 Reproductive Strategies and Population Fluctuations
Species can be divided into two broad categories based on their reproductive strategies:
K-strategists: Organisms that typically reach a stable population as the population reaches the carrying capacity.
r-strategists: Typically, these are small organisms that have a short life, produce many offspring, exploit unstable environments, and do not reach a carrying capacity.

2. 7.6 Reproductive Strategies and Population Fluctuations
K-strategist characteristics include:
Usually occupy relatively stable environments
Large organisms
Long-lived
Produce few offspring
Provide substantial parental care
Reproductive strategy is to invest a great deal of energy in producing a few offspring that have a good chance of living to reproduce.

3. 7.6 Reproductive Strategies and Population Fluctuations
r-strategist characteristics include:
Small, short-lived organisms
Produce many offspring
Little if any parental care
Exploit unstable environments
Usually do not reach carrying capacity (boom-bust cycles)
Reproductive strategy is to produce large numbers of offspring to overcome high mortality.

4. 7.7 Human Population Growth
The human population growth curve has a long lag phase followed by a sharply rising exponential growth phase
Still rapidly increasing
A major reason for the increasing human population growth rate is an increase in medical care
Leads to decrease in death rates

5. 7.7 Human Population Growth
Historical human population growth

6. 7.7 Human Population Growth
The doubling time for the human population is calculated by:
70 / annual rate of increase (%)
( 70 / 2.0% = 35 years )

7. 7.7 Human Population Growth
Doubling time for the human population