For Kim Woods

Module 5 LASA Template

How to use this Template:

Please do not delete any of the instructions/grey text boxes below.

Simply place your work and answers where shown below. Then, save THIS document as your file with your name, and submit to the dropbox in class.

Please submit THIS document AND your Excel sheet.

Please submit BOTH FILES. This will help me to see your complete work.

Creating the Graph:

Click on the M5A1 tab in class and then click on the link called here that will download the Excel worksheet for you. Perform the steps noted below and attached your Excel spreadsheet containing your graph and all of your numbers inputted. Screenshot below of where to find the spreadsheet:

In the spreadsheet, perform the following operations:

1. Input a population value into the box next to Initial Population on the spreadsheet. This population should be anything such as the people, animals, microorganisms, or plants.

2. Input a rate of growth for your population into the box next to Rate 1. Since we are interested in a positive annual percent growth rate per year, this number should be greater than zero percent. Be sure to input this number in the form of a decimal.

3. Repeat the above procedure for Rate 2 and Rate 3. Make sure that the values you select differ by two percent. For example, the values 0.01, 0.03, and 0.05 would be good choices.

4. Under the Time (years) column, input three different year values. Make sure that your values increase by a minimum of ten years. For example, 10, 20, 30 years would be good choices. If you want to see a more dramatic change, select a longer time frame such as 10, 50, and 100 years.

5. When you input all of your data, you’ll see that the spreadsheet has performed the calculations for the future size of each population, rate of growth, and time interval. Additionally, this information will be presented graphically in the chart. To draw an exponential curve for each series, do the following:

a. Right click on the middle point for one of the series.

b. Click on add trendline.

c. Under Trendline Options, select Exponential.

d. Click Close

e. Repeat these steps for the other series.

Attach your Excel file containing the work and graph.

Parts 1 - 3. Calculate what the future size of the population will be, given a specific initial population, rate of growth, and time interval.

Use the exponential equation: Future value = Present value * exp(rt)

exp is the base "e"

r = annual rate of growth expressed as a percent

t = years

In essence, you are REPEATING the calculations that Excel created for you, by manually calculating them using a scientific calculator. You can use google as a scientific calculator. Just input your formula and hit enter. The goal here is to show your set up of the equation and all of your Future Populations Values. Please fill out the below table. Use the Excel spreadsheet to double check your work (your final answers will be the same).

t value	r value (remember this is a decimal)	Formula set up	Final Answer Future Value

See the below example (this was part of the tutorial file, and I am placing it here to remind you what it should look like).

t value	r value (remember this is a decimal)	Formula set up	Final Answer Future Value
5	.05	FV = 50000 * e^(.05*5)	64201
15	.05	FV = 50000 * e^(.05*15)	105850
30	.05	FV = 50000 * e^(.05*30)	224084
5	.07	FV = 50000 * e^(.07*5)	70953
15	.07	FV = 50000 * e^(.07*15)	142882
30	.07	FV = 50000 * e^(.07*30)	408308
5	.09	FV = 50000 * e^(.09*5)	78415
15	.09	FV = 50000 * e^(.09*15)	192871
30	.09	FV = 50000 * e^(.09*30)	743986

Part 4. Examine the graph that your spreadsheet produced based upon the calculations. Did this graph consist of straight lines or curved lines? Describe the shape of these lines for each growth rate. How did they differ? Why?

Place your answer here (minimum 100 words). Please address ALL of the questions above.

HINT: consider: what shape does an “exponential graph” have as opposed to a linear graph. If the graph curves up very quickly, what does it mean? If the graph curves up very slowly, what does it mean?

Part 5. Explain the implications of growth rate for your population. What do you think will happen over a long period of time if a given population of organisms is allowed to increase without limits? Are there environmental factors that keep populations from growing exponentially unchecked? What would be the impact on environmental resources?

Place your answer here (minimum 100 words). Please address ALL of the questions above.

Part 6. Explain the likelihood of your results. Would it be expected that the percent growth rate would stay constant over long periods? Is exponential growth an appropriate assumption for long periods? If not, what other changes in population size might be expected?

Place your answer here (minimum 100 words). Please address ALL of the questions above.

Here is a great resource to get you started:

http://www.nature.com/scitable/knowledge/library/population-limiting-factors-17059572

GRADING RUBRIC:

Assignment 1 Grading Criteria	Maximum Points
Select a population size (population could consist of people, animals, microorganisms, or plants).	20
Select a positive annual percent growth rate per year, which should be greater than 0%.	20
Calculate what the future size of the population will be, given the below assumptions. Use the exponential equation: · Future value = Present value *exp(rt) · Where exp is the base “e” of exponential, · r = annual rate of growth, expressed as a percent · t = years	20
Repeat the calculation for SECOND value of t (make sure they are at least two years apart from one another).	20
Repeat the calculation for THIRD value of t (make sure they are at least two years apart from one another).	20
Graph the results for population growth by % growth rate, vs. time in years for all FIRST calculations of t.	40
Graph the results for population growth by % growth rate, vs. time in years for all SECOND calculations of t.	40
Graph the results for population growth by % growth rate, vs. time in years for all THIRD calculations of t.	40
Explain the implications of this growth rate for the population’s resource use and the environment.	40
Explain the likelihood of your above results. Would it be expected that the % growth rate would stay constant over long periods?	40
Total:	300