14.4 Population and Growth Patterns Warm-Up 14.4 List 3 open-ended and 2 close-ended questions. Place an asterisk to the left of your most important one.
14.4 Population and Growth Patterns KEY CONCEPT Populations grow in predictable patterns.
14.4 Population and Growth Patterns Changes in a population’s size are determined by immigration, births, emigration, and deaths. • The size of a population is always changing. • Four factors affect the size of a population. – immigration – births – emigration – deaths
14.4 Population and Growth Patterns – Immigration: new members of a species coming into an area. – Births: newborns added to a population. – Emigration: members of a species leaving the area. – Deaths: members of a species that died.
14.4 Population and Growth Patterns Population growth is based on available resources. • Exponential growth is a rapid population increase due to an abundance of resources. (memorize the curve shape)
14.4 Population and Growth Patterns • Logistic growth is due to a population facing limited resources.
14.4 Population and Growth Patterns • Carrying capacity is the maximum number of individuals in a population that the environment can support. 1. List three things that would limit a population of coyotes living in the wild. 2. Is there a carrying capacity for humans?
14.4 Population and Growth Patterns • A population crash is a dramatic decline in the size of a population over a short period of time.
14.4 Population and Growth Patterns Ecological factors limit population growth. • A limiting factor is something that keeps the size of a population down. 3. List three limiting factors that would keep caribou populations down.
14.4 Population and Growth Patterns• Density-dependent limiting factors are affected by the number of individuals in a given area. – predation – competition – parasitism and disease
14.4 Population and Growth Patterns • Density-independent limiting factors limit a population’s growth regardless of the density. – unusual weather – natural disasters – human activities
14.4 Population and Growth Facts/Page HW: 14.5 Pgs. 445-447 5 Patterns• Study Guide 14.4 Stop whining1. Movement from one population into another one and get to is called ______. work!2. What are the four factors that affect a population size?3. How does the availability of resources affect population growth?4. Sketch the two different popn. growth curves. Write a brief description next to each one.5. What type of popn. growth curve shows a carrying capacity?6. List three examples of density dependent limiting factors.7. List three examples of density independent limiting factors.