1. Leyda

2. 1. Geographic distribution: the area inhabited by a population.

3. 2. Population density: the number of individuals per unit area.

4. a. high density: lots of individuals per unit area

5. 2. Population density: the number of individuals per unit area. a. high density: lots of individuals per unit area b. low density: few individuals per unit area

6. 3. Growth Rate: how quickly a population changes in size. Fast Growth Rate:Slow Growth Rate: 55 Minutes! 55 Years!

7. 1. ________ rate 2. ________ rate a. birth rate = death rate  population size _________________ b. birth rate > death rate  population size _________________ c. birth rate < death rate  population size _________________ Birth Death stays the same increases decreases

8. 3. immigration: _________________________________ a. example: ___________________________________________ movement of individuals into an area bison immigrates to a meadow full of grass

9. 4. emigration: _________________________________ a. example: ___________________________________________ movement of individuals out of an area bison emigrates out of a meadow without grass

10. 1. ______________ growth: _________________________________ Exponential Individuals reproduce at a constant rate

11. 1. ____________ growth: ________________________________ a. Conditions necessary for exponential growth 1. Unlimited resources 2. Absence of disease and predators b. Example: Bacteria will double their population in 20 mins Exponential Individuals reproduce at a constant rate Staphylococcus aureus

12. c. Shape of graph: J-shaped d. Graph example: Notice: as time goes on, population increases exponentially.

13. 2. ________ growth: ______________________________________ _____________ a. When does population growth slow or stop? 1. Birthrate – Down 2. Immigration – Down 3. Death rate – Up 4. Emigration – Up b. Example: Any animal population in nature. LogisticPopulation grows rapidly until some factor limits growth

14. c. Shape of graph: S-shaped d. Graph example: Notice: as time goes on, population increases then hits a limit and levels off. This limit is the carrying capacity for that population.

15. e. Carrying capacity: Maximum number of individuals that an area can support.

16. Limiting factor: something that causes population growth to decrease. VS

17. A. Density-dependent limiting factors: When population is high these take effect. 1. Competition: Organisms compete for food, water, space, sunlight, and other essentials. Example: Birds and mice both eat seeds. Effect on Evolution: Both species are put under pressure to change in ways that decrease competition. Remember Competitive Exclusion Principle!

18. 2. Predation: One organism eats another. Example: Lynx eats rabbit. Predator: LynxPrey: Rabbit Effect on Evolution: Prey species (rabbit) evolves defenses (speed, camouflage), predators evolve counter-defenses (eyesight).

19. Parasitism/disease: Organisms live in and on a host organism. Examples: Ticks, fleas, leeches, tapeworms, bacteria

20. B. Density-independent limiting factors: Not related to population size. 1. random events: Unusual weather, natural disasters: volcanoes, hurricanes, floods, ice age

21.  Density-independent limiting factors: Not related to population size.  2. human disturbances – such as damming rivers and clear-cutting forests.

22.  Lava Flow  Number of predators  Spread of disease  Especially cold winter  Toxic chemical spill into a stream  Another species competing for same resource  Diverting river for irrigation  Beetles that attack trees