Running Head: ASSIGNMENT 2 1

Assignment 2

Student’s Name

Institutional Affiliation

Date
 Population Ecology Activity

Part I: Constructing a Survivorship Curve

Activity

In the United States, the current average life span of a human female is about 83 years of age,

and the average life span of a human male is about 77 years. For this activity, we will assume

that the average life span is 80 years of age. For Table 2a below, age brackets in five-year

increments were created. Age data was collected randomly from 100 newspaper obituaries from

around the United States and entered into the age bracket Table 2a. Using this data, you will

complete the survivorship information in Table 2b and construct a survivorship curve using an

Excel spreadsheet table. You will create a graph from the data and import it later in this

assignment.

Completing the Survivorship Data Table Procedure (Table 2b) (10 points)

1. Enter the data from “Number of Deaths” column for each age bracket in Table 2a into the

“Number of Deaths” column in Table 2b.

2. To calculate the data for the “Number of Survivors” column in Table 2b, start by subtracting

the number of deaths in age bracket 1-5 from the number of survivors in age bracket 0. This

number will be 100, of course. Continue subtracting the number of deaths in each age bracket

from the number of survivors in the preceding age bracket. (Hint: The number of survivors will

be 100 until you get to age bracket 21-25, where you will subtract 2, making the number for that

bracket 98. Continue the process through the last age bracket. The number of survivors in age

bracket 91-100 should be 0).

3. Create a line graph using Microsoft Excel and the data from Table 2b. The X-axis should

reflect the Percent Life Span (%) and the Y-axis data should reflect the number of survivors data

that you calculated.

 Table 2a

Age Bracket Number of Deaths

0 0
1-5 0
6-10 0
11-15 0
16-20 0
21-25 2
26-30 0
31-35 6
36-40 4
41-45 0
46-50 2
51-55 2
56-60 8
61-65 2
66-70 8
71-75 10
76-80 16
81-85 8
86-90 22
91-100 10
Total 100
 Table 2b

Age Bracket (Age of Percent of Life Span Number of Deaths (from Table Number of

Death) (%) 2a) Survivors

0 0 0 100
5-Jan 3.1 0 100
10-Jun 9.4 0 100
15-Nov 16 0 100
16-20 22 0 100
21-25 28 2 98
26-30 34 0 98
31-35 41 6 92
36-40 47 4 88
41-45 53 0 88
46-50 59 2 86
51-55 66 2 84
56-60 72 8 76
61-65 78 2 74
66-70 84 8 66
71-75 91 10 56
76-80 97 16 40
81-85 100 8 32
86-90 100 22 10
91-100 100 10 0

Complete The Graph (12 points)

 Number of Survivors
120

100
Number of Survivors

80

60

40

20

0
0 3.1 9.4 16 22 28 34 41 47 53 59 66 72 78 84 91 97 100 100 100

% of Life Span

(Questions: 6pts each)

1. What type of survivorship curve do modern humans possess?

Type I curve; here many of these organisms tend not to die at an early age but they do go up
to the late stages of their life before they can die. This kind of curve is major here as death is
mainly witnessed in the elderly ones.

2. Would you expect that there is a difference in the survivorship of men and women? Explain

why, or why not?

In numerous corners of the globe, the female gender have been termed by many researcher
that they are likely to live longer than the female gender. However, in the early century of
19th, females were not characterized by the long life which has greatly changed today. This
favoritisms in the women’s favor has been observed to row over the time. However, there has
not yet been any concrete proves put forward to ascertain the assertions made by those
scholars. But just to mention; behavioral, environmental effects, as well as biological factors
could have contributed to this.

3. Why do humans exhibit this type of survivorship curve? What factors are involved?

They have very large age span to survive, their young ones are well taken care of and thus
able to live to maturity.

4. Why might obituaries be a poor source of data for determining a human survivorship curve?

It’s reported that only just but a limited number of the obituaries in the newspapers though
does not stand for the actual number of casualties in an area.
5. The data for this exercise was collected from the United States. Would you expect to see the

same curve from data collected in a developing (i.e., under-developed) country? What might the

differences be, if any?

The curve, for a very much developed economy state is deemed to be very gradual as
compared to the growing economy. Growing country displays numerous death rates thus a
much shortened life span.

Part II:

China

Instruction: Go to “Country,” and select “China: 1.36 B.” The gray “Vital Rates” box will show

the birth rate (1.52 per woman) and death rate (1.05% per year) for the year 2015.

(Questions: 6pts each)

6. Based on what you know about the different shapes of the age structure diagrams, what kind

of growth is China’s population is experiencing?

From the statistics of the 2019 close to the 70.6% of the china population was noted to be in
the working bracket of 15-64. And those that have retired or left the job make up the 12%.
The county’s population is still coming up , albeit at a very slow rate. This is since

7. In 2015, which two age brackets have the highest number of individuals?
 Grown-ups of 25 to 29 years this is as per the observation on the population distribution
graph visuals.
Other bracket is 45-49 the males are close to 60 million while females are over 60millions

Instruction: Now click the green “Run” button, and watch the changes that happen through the

year 2050 (the simulator will stop at 2050 automatically).

8. In 1979, China implemented the well-known One Child Policy in an effort to slow an

exploding population. Looking at the population curve and the changes in the age structure

diagram through 2050, what were the results of the policy? Did it work? How do you know?

The policy did work properly as it’s reported that almost 400 million births were averted as a
result of this policy. The birth rate has gone down as we see the number of child born has
greatly decreased.

Instruction: Click the green “Run” button again, and watch the changes that happen through the

year 2100 (the simulator will stop at 2100 automatically).

9. If the One Child Policy is kept in place through 2100 and birth and death rates stay the same,

how does the age structure of the population change? Why might this become a problem in an

industrialized society?
The projected population will for sure go high but then by the year 2040 it starts to decline.
The simulated figures however having 2020 as the pick figures, it starts to go down all the
way through the entire period. The population for those who are over 65+ also declines but
with a very small margin. This variance in the population especially on the working bracket is
likely to affect the economy of the country in terms of the GDP.

Instruction: Click ”Reset” and then click the “Birth” tab, and click the “up 5%” button seven

times to where the birth rate is about 2.12-2.15 per woman. Click apply, and run the simulator

through the year 2200.

10. All other parameters being consistent what does the age structure diagram’s pattern tell us

about China’s population if birth rates are raised to 2.15 per woman through the year 2200?

The projected population still declines but will a very small margin. However the population
aged 65+ seems to increase throughout until it reaches some point where the curve flattens.
Simulated population on the other hand indicates that the population will co tine growing
until after 2030 when it starts to decline.

USA

Instruction: Let’s change countries now. Go to “Country” at the top of the page, and click

“USA: 321 M.” Click “Run” twice to cycle forward to the year 2100.

The population generally is growing in numbers for all the ages until the age bracket f 55+
which seems to start decreasing. The population for the age bracket of 65+ continues growing
until close to the year 204 where it starts to go down but at some point it gets flat and
maintains the level for the entire period. The population is very stable as a trend or pattern
can easily be deduced where the young population is growing constantly while the elderly
population is declining momentarily.
11. Given the current birth rate of 1.98 per woman in the U.S. and a 1.36% per year death rate,

what kind of pattern do we see in the age structure diagram through the year 2100? Is our

population declining or increasing? Is it generally stable?

Instruction: Click “Reset” and increase the birth rate by 5% to 2.08 per woman (Do not forget

to click “Apply”). Run the simulator through 2100.

12. What does this slight change do to the U.S. population? Is it generally stable or unstable by

2100?

The change in birth rate to 2.08 does not cause much variance in the pattern of the population.
The population seems to maintain its structure as before. And hence it’s also stable.

Instruction: Lastly, click on each country in the drop-down menu at the top of the page, and

look at the 2015 default age structure diagram for each.

13. Which two countries’ default diagrams for 2015 best represent rapid population growth?

Iraq and India they both have very high birth rates. And the curve on the graph of the
population indicates a very ballooning population with each passing period.