1. Extinction
BrainPOP movie:

2. Extinction (write) when a species of an organism no longer exists
Main causes:
Over hunting
Predator
Lack of resources
Habitat destruction
Natural disaster
deforestation

3. Population growth BrainPOP video

4. Population Density (write)
Population density is the number of individuals in a specific area.

5. Population Density = # of Individuals Unit area
3 meters
5 meters

6. Pop. Density = 16 butterflies
5 m x 3 m
Pop. Density = 16/15 m2
Pop. Density = per sq. meter

7. Population density (write)
Number of individuals divided by the size of the area
Ex. 16 spiders in an area that measures 2 meters x 2 meters
Area = length x width
16 spiders / 4 meters ²
Simplify: 4 spiders / meter ²

8. Relationships Among Living Things2
Population Density
Ecologists determine population density (DEN suh tee) by comparing the size of a population with its area.
For instance, if 100 dandelions are growing in a field that is one square kilometer in size, then the population density is 100 dandelions per square kilometer.

9. Carrying capacity (write)
Maximum number of organisms that are able to live in a certain area
An area can only support so many organisms

10. Populations can change in size when new members enter the population or when members leave the population.
Immigration means moving into a population.
Emigration means leaving a population.

11. Birth and Deaths
Birth Rate is the number of births in a certain time period.
Death Rate is the number of deaths in a population in a certain amount of time.

12. Population Equation
If birth rate > death rate, population size increases.
If death rate > birth rate, population size decreases

13. Characteristics of Populations
Relationships Among Living Things 2
Characteristics of Populations
Ecologists ask questions to describe populations.
They want to know the size of the population, where it members live, and how it is able to stay alive.

14. Relationships Among Living Things2
Studying Populations
To study migrating monarchs, a "monarch watcher"—often a school student like yourself—carefully catches a monarch and attaches a tag to one of its wings.
Later, someone else who catches the same butterfly can use the tag to figure out how far the butterfly has flown.