Populations

What is a population?• Group of organisms that belong to the same species and live

in a particular place at a particular time

Population Density

Dispersion

Survivorship Curve

Type III Survivorship = R selected• Because they live in an unstable environment with many

densitry independent limiting factors they…1. Remain small2. Use little energy to make each individual3. Produce many offspring4. Mature early5. Die early6. Individuals reproduce only once

Type I or II survivorship = K selected• Because they live in a stable environment with many density

dependent limiting factors they…1. Are large2. Use a lot of energy to make each individual3. Produce few offspring4. Mature slowly5. Have long life expectancy6. Reproduce more than once

Immigration vs. Emigration

Calculate the growth rate if…• There is a population of 1500 people• 50 people die in one year• 75 people are born in the same year

• Growth rate = birth rate – death rate

• Birth rate = # of births/total population• Death rate = # of deaths/total population

• When will population size increase? Decrease?

Exponential Model

In order for this to occur, the population requires _____________resources.

Logistic Model

What is K?

Density Independent Factors

What are some examples?

Density Dependent Factors

What are some examples?

Human Population

Developed vs. Developing Countries