1. Populations
How much is too much?

2. What defines a population?
A group of individuals
- within the same species
- living within the same area
- during a specific time
Levels of Organization review: organisms -> populations -> communities -> ecosystems -> biome -> biosphere

3. Population characteristics
Sex ratio (males:females)
Age distribution
Population density
Spatial distribution
Size

4. What changes the size of a population?
Natality (birth rate)
Immigration
Mortality (death rate)
Emigration

5. Factors that influence population growth rates
Density-independent/extrinsic limiting factors
- Chance
Density-dependent/intrinsic limiting factors
- Availability of raw materials
- Availability of energy
- Accumulation of waste products
- Interactions among organisms

6. Population Growth Models

7. Reproductive Strategies
Populations of K-strategists
- long lifespan
- few offspring
- care for offspring
- reaches carrying capacity
Populations of r-strategists
- short lifespan
- many offspring
- little to no care for offspring
- does not reach carrying capacity