BIO / GES 344 - Ecology
Human Survivorship / Ecological Informatics Lab Exercise
Last week, you conducted a field survey of a local cemetery to
determine the birth and death dates of individuals buried there.
As you recall, you subsequently entered the data into a
spreadsheet. Following that session, the data from each student
were compiled into a single database that was subsequently
formatted into HTML and posted to the Internet.
The purpose of today’s session is two-fold. The first is to teach
you how to access that dataset from the Internet and convert it
back into a spreadsheet format. The second is to have you
manipulate that dataset to answer general questions about
human survivorship. Appended to these instructions is a set of
questions that you are to address. You are to detach that sheet
and submit it as part of a report that will be worth 20 lab points.
A. Obtaining data from the Internet
Image from
www.sojournertruth.com
The Internet is fast becoming a vast repository of raw data covering virtually all fields of
science. Much of those data are presented as matrices of rows and columns suitable for
downloading and further analysis. The ability to identify, access, and manipulate on-line
information will be a critical skill that scientists will need to master in the coming decade.
Methods for identifying appropriate datasets are quickly evolving. In many instances,
data will be identified by separate files containing metadata, which describe the
parameters contained in the individual datasets. Searches can be conducted for
appropriate parameters in the metadata, thus enabling appropriate data to be identified.
For this investigation, the posted data from your cemetery investigation have been linked
to a page that provides links to a variety of ecological databases. Housed at Wilkes, the
linking page is sponsored by the Education Section of the Ecological Society of America,
and is available to faculty and students worldwide.
Open your web-browser and go to the dataset as directed by your instructor. Once you
have opened the page, save it to your computer as a text file. The file name should be
automatically given.
Next, open the Microsoft Excel application. Then open the saved file. You should be
presented with a series of dialog boxes that will help you appropriately format the data
into columns within the spreadsheet. Pay careful attention to getting the name code into a
single column. In all, you should have five active columns, representing name, gender,
year of birth, year of death, and age.
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Once you have the data formatted by the dialog boxes, click “OK” which should open the
appropriately formatted spreadsheet. Save the spreadsheet under a suitable name. You
might want to copy that file to a floppy, zip, or thumbdrive for subsequent analysis.
B. Analyzing the data
Once you have the data in an appropriate format, you are then asked to organize it into a
way that provides survivorship information. The easiest way to do this is to perform a
sort according to age. By doing so, it will be relatively easy for you to determine the
number of individuals dying at a given age. Then, you can calculate survivorship by
cumulatively tallying the number of deaths at each age to give the number alive at each
age. That information should be recorded on a separate page of your spreadsheet. You
can then create a graph of the relationship between the number of survivors (y axis) as a
function of age (x axis). To obtain a survivorship curve, perform a log transformation of
the number of individuals, and then plot that column as a function of age.
Further analyses are possible by sorting on specific columns in the original spreadsheet
and then cutting and pasting blocks of data. For example, you can determine differences
in survival between males and females by sorting for gender (column B), cutting the rows
containing males from those of the females, and pasting into a separate worksheet. Sort
each according to age, and then tally according to number dying as you did before for the
whole dataset. The tally table should have three columns: age, number of females alive
at each age, and the number of males alive at each age. A figure showing the number of
males and females alive as a function of age can then be created. Survivorship curves
can be similarly created by applying the necessary log transformation.
Similarly, determining survivorship of cohorts being born at different times can be done
by sorting the whole dataset according to age at birth, and then cutting and pasting blocks
of individuals based on how you define each cohort.
C. Your report
The minimal report for this exercise will consist of the following:
1. A completed question sheet (see next page)
2. A graph that shows survivorship for the entire dataset
3. A graph that shows survivorship of males as opposed to females
4. A graph that shows survivorship of individuals born at fifty year intervals
Additional analyses are welcome.
BIO / GES 344 Cemetery Demography / Ecological Informatics Lab
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BIO/GES 344 - Ecology
Human Survivorship Lab Exercise
Name_____________________________
Given the data on human survival collected last week, calculate lx and plot survivorship
according to the instructions provided. Then answer the following questions:
1. Did human survivorship approximate a Type I, Type II or Type III function? Explain
any deviation from the idealized norms.
2. Was there a difference in survivorship between males and females? If so, explain.
3. Did survivorship at all change for people born at different times over the past 200
years? Explain.
4. How effective were the methods used in assessing human survivorship? What
changes or improvements in this exercise would you suggest?