Limiting factor – any condition of environment that limits size of population.

The number of owls have decreased because their habitat has been destroyed by logging.

Exponential growth – occurs when rate of growth in each new generation is a multiple of previous generation.

Immigration – movement of organisms into area occupied by an existing population.

Emigration – movement of organisms out of an area where population is located.

Growth rate = Change in number of individuals / time period.

Darwin observed populations remaining at a stable size even when large numbers of offspring are produced yearly.

Carrying capacity - # of organisms that can be supported by environmental resources in a given ecosystem.

Competition – occurs when organisms try to make use of same resources.

A large population of prey animals can lead to increase in predator population.

Parasitism – relationship in which one organism feeds on tissue or body fluids of another organism.

Parasitism is density-dependent limiting factor because parasites can spread easily in a crowed host population.

Human population is growing at an exponential rate.

During poor sanitation and inadequate medical care, infant death rate and women dying during childbirth was high.

During the 200-year period of Industrial Revolution, the population doubled.