Population Dynamics

Population Growth  All organisms are members of populations  Populations die and grow at steady rate based on the amount of resources available

Exponential Growth  Populations experience exponential growth  Initial increase in organisms is slow (small number of reproducing organisms)  Population then sharply increases due to high amount of reproduction

Exponential Growth  In exponential growth a populations rate of production grows  Limitations:  Availability of food  Disease  Predators  Lack of space  A populations carrying capacity is the number of organisms than an environment can support  Births exceed deaths until resources run out

Density  Density Dependent Factor-Factors that have a stronger effect with increasing population  Disease  Predators  Parasites  Competition for food  Density Independent Factor-Affects the population regardless of density:  Volcanic Eruptions  Storms  Temperatures  Drought

Human Population  Demography-Study of human population size, density and distribution  United States Census is taken every 10 years

Human Population  Human growth is different from other organisms because humans have the ability to change their environment  Found cures for diseases  Found methods to produce food  Been able to provide clean water

Age Structure  Age Structure-Proportions of the population that are in different age groups  Age structure graph shows how many males and females there are in each age group