Chapter 5 - Populations Photo Credit: http://www.flickr.com/photos/solidether/1084349065/

5-1 How Populations Grow Geographic distribution – the area a pop lives(range)

Population Density – the number of individuals in an area

Population Growth Number of births Number of deaths Emigration (out) & Immigration (in)

In Springfield, 45 babies are born in the year 2008 In Springfield, 45 babies are born in the year 2008. 15 people died that same year. What is the growth rate for the city? Positive Growth rate = increase Negative Growth rate = decrease

Exponential Growth –reproduction at a constant rate. - occurs under ideal conditions (no limits) - J-shape curve

Logistic Growth – resources become less available, growth slows or stops - S-shaped curve Carrying Capacity – the number an environment can support

5-2 Limits to Growth Limiting Factor – causes population growth to decrease Density- Dependent Factors – population size --competition --predation --disease

Density-Independent Factors – does not depend on population size -Unusual weather -Natural disasters -Some human activities

Predator - Prey Relationship - predators control populations - as the prey numbers increase, so do predators Prey will always outnumber predators!

1. The area where a population live is called: Quick check. 1. The area where a population live is called: a) population density b) geographic distribution c) carrying capacity 2. The graph shows why type of curve? a) exponential b) logistic 3. The arrow indicates the: a) limiting factor b) density dependent c) carrying capacity 4. What is the number of deer that can be supported by the island? a) 90-96 b) 75-80 c) 10 -30

5. What information is needed to determine the population growth rate? a) birth rate b) death rate c) number of immigrants d) all of these 6. A flood causes a 30% reduction in the population of crocodiles. This is considered a: a) density independent factor b) density dependent factor c) logistic growth factor 7) If an area is a negative rate of population growth, then the population is: a) increasing b) declining c) extinct 8) Population density refers to: a) the number of individuals in an area b) the total number of individuals in a species

DEMOGRAPHY

- the study of human population growth - explains how populations change over time. Detroit

Demographic Transition – a dramatic change in birth and death rates -U.S., Japan, and Europe population growth has stopped ZERO POPULATION GROWTH

In order to achieve ZPG, each couple has only 2 children.

AGE STRUCTURE DIAGRAMS Show percentage of people alive at each age group

Which diagram above is: 1. A country where the king orders the deaths of all the baby boys 2. A country at war, many young men die in that war 3. A country with poor health care for women, many die in childbirth 4. A country where AIDS kills people in their 30s

Issues in Biology Animals are classified as ENDANGERED when their numbers are low This means that they may become extinct.

Congress passed the Endangered Species Act (ESA) in 1973 The ESA protects endangered and threatened species and their habitats by prohibiting the “take” of listed animals. Take means “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect or attempt to engage in any such conduct.” Only applies to animals in the U.S. International laws protect animals in other countries Black Footed Ferret