1. Population Curves and Diversity

2. 3 Phases of Population ► Growth ► Stability ► Decline

3. Growth of Population ► Population growth occurs when available resources exceed the number of individuals able to exploit them  As a result, reproduction is rapid and death rates are low causing a net increase in the population size

4. Population Stability ► Population stability is often preceded by a crash  Caused by the growing populations to outstrip its available resources  Stability is usually the longest phase of a population’s life cycle

5. Population Decline ► Caused by a decrease number of individuals in a population ► May eventually lead to population extinction

6. Exponential Growth ► Nearly all populations will tend to grow exponentially as long as resources are avaiable ► Exponential rate happens due to reproduction being a multiplicative process

7. 2 Factors Affecting Population Growth ► Natality: birth rate ► Mortality: death rate ► Population growth rate can be determined by subtracting death rate from birth rate

8. 2 Modes of Population Growth ► Exponential mode: J curve, happens when there is no limit to population size ► Logistic mode: “S” curve, depicts the effect of a limiting factor Reference: http://www.emc.maricopa.edu/faculty/farabee/biobk/expgrowth.gifhttp://www.emc.maricopa.edu/faculty/farabee/biobk/expgrowth.gif