Population Dynamics

1. Population Dynamics May 4, 2012 Kyle Jager

2. Populations • A population is all the members of one species that live in a defined area • Populations fluctuate based on environmental factors • Predators • Food Supply • Water • Natural Disasters • Shelter

3. Dispersion • The distribution of species in an area can very greatly • Clumped – sections of population group together • Even – population spread evenly across area • Random – population randomly exists in the area

4. Communities • Predators and prey populations positively correlate to the population one another • As prey populations increase, there is more food available to the predators so their populations rise. • Community- all the members of all species that live in a defined area

5. Population Pyramids • Population distributions can be displayed through graphs by both sex and age. • Expanding – birth rate > mortality rate • Stationary – birth rate = mortality rate • Contracting – birth rate < mortality rate

6. Influences on populations • Immigration and emigration • Birth and death • Why do populations stop growing? • Exponential growth cannot be maintained with limited resources. Instead populations have a logistic curve and reach a limit called the carrying capacity.

7. Human Population Growth • Human population growth appears to be growing very rapidly. Does this make our species except to the carrying capacity rule? • To determine how human populations have changed over time, you will analyze the population of US age groups between 1980 and 2010. • Please review some population pyramids of countries around the world to gain a better understanding of how societies differ over time. Links can be found in the “Interactive” blog post.