1. #26 Population dynamics

2. Warm-up: Trophic Level Autotroph or heterotroph
Producer, primary consumer, secondary consumer, tertiary consumer
Human
Snake
Giraffe
Deer
Algae
Owl

3. No population can grow forever
No population can grow forever. Every population has a limit to its growth based off the number of available resources.
*A limiting factor prevents the continuing growth of a population within an ecosystem.
There are several things that can limit a population, we will learn the terminology in the following slides

4. *Population limiting factors
Population growth rate is how fast a given population grows
Factors that influence this are:
Natality ( _________ rate)
Mortality ( _________ rate)
Emigration (the number of individuals moving _____________ a population)
Immigration (the number of individuals moving ____________ a population)
birth
death
away from to

5. *Population Characteristics
Population Density:
The number of organisms per unit area
Spatial Distribution:
Dispersion: The pattern of spacing a population has within an area
3 main types of dispersion
Clumped
Uniform
Random
The primary cause of dispersion is resource availability

6. *Population Limiting Factors
Density-independent factors
Factors that limit population size, regardless of population density.
These are usually abiotic factors
They include natural phenomena, such as weather events
Drought, flooding, extreme heat or cold, tornadoes, hurricanes, fires, etc.

7. *Population Limiting Factors
Density-dependent factors
Any factor in the environment that depends on the number of members in a population per unit area
Usually biotic factors
These include
Predation
Disease
Parasites
Competition

8. Clarifying classification
shows organisms that share a common ancestor. These organisms are closely related
shows similarities between evolved organisms

9. The world population continues to grow due to the average life expectancy increasing from 68 year old in 1950 to 80 years old in In addition to people living longer, people are continuing to reproduce and have offspring.

10. What is density? How would you calculate the population density of…
Total Area:
Washington D.C
Population:
Washington D.C. 646,449
Which states do you predict will have the 20 largest densities?

11. Population Density assignment questions

12. Label all the states
Create a legend and color the top 20 states with the highest population density one color
Color the 20 lowest density states another color and add to your legend
Which states surprised you about their population density? Why?
The square mileage listed accounts for land and water miles, do you think any of the rankings would change if you just calculated land mass only? If so which states? If you say no explain why
If you had to calculate the population density of the entire United States, where do you think it will fall in your rankings from largest to smallest? Around what number? (This is a prediction)
Do you think it will be larger or smaller then the pop Density of NC? Explain why?
Find the 2012 population of USA (use BYOT) and the total square miles and find the pop density
How correct were your #6 and #7? Explain mistakes you made and why those new numbers you found are logical?
This week’s theme of reading across the board is “Main Idea,” why do you think it’s important to understand population density? What does it tell us about people, location, and resources?

13. extra

14. What population do you think this is?

15. Understanding Exponentials
Put your pens down for a minute & think about this:
An employer offers you two equal jobs for one hour each day for fourteen days.
The first pays $10 an hour.
The second pays only 1 cent a day, but the rate doubles each day.
Which job will you accept? 15

16. Understanding Exponentials
Population Ecology: Population Growth Rate
Understanding Exponentials
Now, how much would your employer owe you if you stayed at this job for another 2 weeks?
Job 2 lags for a long time before exponential growth kicks in!
What would happen if this type of growth took place within a population?

17. Creative Writing
Each group will work together to develop the beginning of a story.
Introduce your characters, setting, problem (limiting factor), and size of population in that characters community
Pass your story to the next group
2. Each group will read the introduction of the their new story, and:
Explain how the characters are being affected by the problem introduced in Part 1 (what fears/concerns does this organism have for his/herself and his population
3. Each group will read their new story, and write its ending:
Explain what happened to the character and his/her population as a result of the problem; will they be doing anything to re-build their population?
Explain the impact this problem had on the overall population size?

18. The most straightforward chain of argument goes…
As the # of organisms increase
Resources Become more limited
Competition Among Individuals for Resources increases
Competition has Effects on Birth and Death Rates
SO…
Does this “regulate” or just limit population size?