Syllabus: BIOL 6301-046
Advanced Topics in Biology - Statistical Analysis
of Ecological Communities
Spring 2021
Tuesday – an asynchronous lecture will be posted
on YouTube; corresponding notes and assignment will be posted on this
website
Thursday, 1:00-2:20 p.m. – Iroro and I will be available
live via Zoom to answer questions
Dr. Nancy McIntyre
806-834-7977
nancy.mcintyre@ttu.edu
Teaching Assistant: Iroro Tanshi (iroro.tanshi@ttu.edu)
Office hours: Will be
done virtually (via Zoom) by appointment; email either me or Iroro to set up a time.
Course overview: This course is designed to
familiarize you with the analysis of ecological community data, and to teach
you how to do so using the R software environment (powerful freeware that is
now perhaps the most commonly used package for statistical analysis in
ecology). We will use example data typical of community ecology studies
(i.e., abundance and/or occurrence data for multiple species at multiple
sites that differ in environmental characteristics). In each case, there
will be observations of multiple species and observations of multiple
attributes of the environment at each sampling area. Data analysis will be
followed by interpretation and communication of findings via written
assignments.
This course will be entirely online. Students must
therefore have the following required technology and skills needed
for this course: You will need access to a PC or Mac desktop, laptop, or
tablet computer; a smartphone will be insufficient. We will be using
R/RStudio to conduct all analyses; prior experience with R will be helpful
but not necessary. Students will be expected to load the computer they will
be using with a copy of R, RStudio, and all necessary materials. You will be
accessing links to the internet and using
YouTube to access video lectures. For internet access, the Chrome
browser is recommended. Finally, I will send out announcements and
assignments via email; please make sure that I have your current TTU
email address on file, and check to ensure that emails from me are not going
to your Junk folder. You will also use email to turn in your assignments.
Expected learning outcomes: This is a
practical, hands-on course on the statistical analysis of ecological
community data; we will cover main types of multivariate analyses currently
used by community ecologists, including use of diversity indices, various
forms of ordination, cluster analysis, and others. We will be using the R
computer environment (chiefly RStudio) to conduct all analyses. Students
will be expected to load their personal computers with a copy of the R
package, RStudio, and all necessary materials. No prior experience with R is
necessary.
Methods for assessing expected learning outcomes:
Your grades will be based on weekly homework assignments; there are no
exams. Although these assignments will require you to successfully conduct
statistical analyses of ecological community data in R, the primary
assessment will be on your ability to interpret the output from your
analyses and draw appropriate ecological conclusions from them.
Grading: All assessment will be via weekly assignments in RMarkdown (no tests). Your weekly assignments should be turned in as Word documents via email to iroro.tanshi@ttu.edu no later than 8:00 a.m. on Monday of the following week. In your email, please include the following as the Subject line: Assignment on ____ (you will fill in the blank with the week’s topic; for example: Assignment on PCA)
Potential for course modality change: As per TTU: “If Texas Tech University campus operations are required to change because of health concerns related to the COVID-19 pandemic, it is possible that this course will move to a fully online delivery format. Should that be necessary, students will likely need a webcam and microphone and will be advised of additional technical and/or equipment requirements, including remote proctoring software.” Since this course is already online, we’re covered.
Illness-based absence policy: If at any time during this semester you feel ill, in the interest of your own health and safety as well as the health and safety of your instructors and classmates, you are encouraged not to attend face-to-face class meetings or events. Please review the steps outlined below that you should follow to ensure your absence for illness will be excused. These steps also apply to not participating in synchronous online class meetings if you feel too ill to do so and missing specified assignment due dates in asynchronous online classes because of illness.
1. If you are ill and think the symptoms might be
COVID-19-related:
a. Call Student Health Services at (806) 743-2848 or
your health care provider.
b. Self-report as soon as possible using the
ttucovid19.ttu.edu
management system. This website has specific directions about how to
upload documentation from a medical provider and what will happen if your
illness renders you unable to participate in classes for more than one week.
c. If your illness is determined to be
COVID-19-related, all remaining documentation and communication will be
handled through the Office of the Dean of Students, including notification
of your instructors.
d. If your illness is determined not to be
COVID-19-related, please follow steps 2a through 2d below.
2. If you are ill and can attribute your symptoms to
something other than COVID-19:
a. If your illness renders you unable to attend
face-to-face classes, participate in synchronous online classes, or miss
specified assignment due dates in asynchronous online classes, you are
encouraged to visit with Student Health Services at (806) 743-2848 or your
health care provider. Note that Student Health Services and your own and
other health care providers may arrange virtual visits.
b. During the health provider visit, request a
“return to school” note.
c. E-mail the instructor a picture of that note.
d. Return to class by the next class period after the
date indicated on your note.
Following the steps outlined
above helps to keep your instructors informed about your absences and
ensures your absence or missing an assignment due date because of illness
will be marked excused. You will still be responsible to complete within a
week of returning to class any assignments, quizzes, or exams you miss
because of illness. Links for additional info:
Student Health
Students with disabilities: Any student who,
because of a disability, may require special arrangements in order to meet
the course requirements should contact me as soon as possible to make any
necessary arrangements. Students should present appropriate verification
from Student Disability Services. Please note that instructors are not
allowed to provide classroom accommodations to a student until appropriate
verification from Student Disability Services has been provided. For
additional information, please contact the Student Disability Services
office at 335 West Hall or (806) 742-2405.
Religious holy day statement: "Religious holy
day" means a holy day observed by a religion whose places of worship are
exempt from property taxation under Texas Tax Code §11.20. A student who
intends to observe a religious holy day should make that intention known in
writing to the instructor prior to the absence. A student who is absent from
classes for the observance of a religious holy day shall be allowed to take
an examination or complete an assignment scheduled for that day within a
reasonable time after the absence. A student who is excused under section 2
may not be penalized for the absence; however, the instructor may respond
appropriately if the student fails to complete the assignment
satisfactorily.
Academic integrity: Academic integrity is
taking responsibility for one’s own class and/or course work, being
individually accountable, and demonstrating intellectual honesty and ethical
behavior. Academic integrity is a personal choice to abide by the standards
of intellectual honesty and responsibility. Because education is a shared
effort to achieve learning through the exchange of ideas, students, faculty,
and staff have the collective responsibility to build mutual trust and
respect. Ethical behavior and independent thought are essential for the
highest level of academic achievement, which then must be measured. Academic
achievement includes scholarship, teaching, and learning, all of which are
shared endeavors. Grades are a device used to quantify the successful
accumulation of knowledge through learning. Adhering to the standards of
academic integrity ensures grades are earned honestly. Academic integrity is
the foundation upon which students, faculty, and staff build their
educational and professional careers. [Texas Tech University (“University”)
Quality Enhancement Plan, Academic Integrity Task Force, 2010]
Academic dishonesty: Academic dishonesty
includes, but is not limited to, cheating, plagiarism, collusion, falsifying
academic records, misrepresenting facts, and any act designed to give unfair
academic advantage to the student (such as, but not limited to, submission
of essentially the same assignment for two courses without the prior
permission of the instructor) or the attempt to commit such an act. If a
student is involved in any form of academic misconduct and is proven that
the action took place, the instructor may initiate a disciplinary action.
The penalties for academic dishonesty can include but are not limited to a
zero or a grade of "F" on the work in question, a grade of "F" in the
course, or suspension. Please make sure that you review the university’s
Academic Integrity Policy (https://www.depts.ttu.edu/opmanual/OP34.12.php).
Recommended references on community
ecology analyses:
Multivariate Statistics for Wildlife and Ecology Research
(McGarigal
et al., 2000) – although this book is somewhat dated now, it provides a
clear explanation for many multivariate stats tests that are used in
wildlife biology and ecology; this book would be most useful if you have
already had a basic statistics class
Community Ecology: Analytical Methods using R and Excel
(Gardener,
2014) – this book covers how to perform some basic analyses on
biodiversity data in both R and Microsoft Excel
Recommended references for learning and using R:
Getting Started with R: An Introduction for Biologists, 2nd
ed. (Beckerman et al., 2017) – this is a very good and short book that
will teach you how to load data, do some simple stats tests (t-test, ANOVA),
and make some simple plots/graphs
The R Book, 2nd ed.
(Crawley, 2012) – this is the
comprehensive reference for R
Important notes: This is a new course, and it
is the first time that I will have taught a course entirely online. I will
be teaching out of my home from my old laptop (because my work desktop does
not have a camera). I will be working from a PC platform but anticipate that
several of you will be using Macs. Finally, I developed and maintain this
website, which is not part of TTU’s Blackboard platform. Not using
Blackboard has pros and cons. I do not use it primarily because I make my
teaching materials available to everyone worldwide and not just enrolled TTU
students (Blackboard materials require a TTU login whereas my website and
YouTube channel do not). For all of these reasons, I expect there to be
quite a few technological glitches. Please inform me of any problems right
away!
Moreover, there is a very large
disparity in students in terms of previous experience with R and with data
analysis. (That is, some of you will already be experienced with
these things whereas other students will have had no experience with them.)
This disparity may make live video sessions uncomfortable for those students
who don’t understand something; such a student may be reluctant to speak up
if he/she thinks (based on questions/discussion in the live sessions, etc.)
that he/she is the only one to not “get it.” Please do not hesitate to ask
questions. You can also contact me or the T.A. to set up an individual
appointment on Zoom.
1. First, read the week's online notes and
work through the R scripts.
2. Then watch the
lecture video.
3. Then do the assignment.
List of topics to be covered:
2. Introduction to R
R – see primers at
https://rstudio.cloud/learn/primers
RStudio
RMarkdown – see primers at
https://rmarkdown.rstudio.com/
Loading and manipulating site x species and site x environment data
Simple graphical summaries and basic statistical analyses of data
3. How do I describe the structure of a community?
Richness + evenness = diversity
Abundance
4. How do I
measure other dimensions of biodiversity?
Phylogenetic and
functional diversity
5. How do I summarize complex relationships and
identify the most important patterns from a near-infinite number of possible
arrangements of multivariate data ?
Ordination
6.
How do I identify the most important variables driving patterns in a large
dataset of correlated variables (and then use those variables in other
analyses)?
Principal Components Analysis (PCA)
Redundancy Analysis (RDA)
7. How can I determine which environmental variables
are associated with species occurrences at different sites?
Nonmetric Multi-Dimensional Scaling (NMDS)
Canonical Correspondence Analysis (CCA)
8. How do I determine whether my data are grouped?
Cluster Analysis
9. If I have communities with a priori
groupings, how do I determine whether those groups are valid?
Discriminant Function Analysis (DFA) via CART (Classification and Regression Trees)
Day |
Date |
Topic |
Links to Materials |
Th |
21 Jan. |
No live session: Install R and RStudio on your home computer and
work through primers on your own (if you are unfamiliar with R) |
R primers:
https://rstudio.cloud/learn/primers |
Tu |
26 Jan. |
Introduction to the course and to ecological communities |
Click on this link for notes YouTube URL: https://youtu.be/a2io3F5JZI8 |
Th |
28 Jan. |
Introduction to live session structure |
1:00-2:20; Zoom link will be emailed |
M |
1 Feb |
No assignment this week |
- |
Tu |
2 Feb. |
Introduction to R, R Studio, and RMarkdown |
Click on
this link
for notes YouTube URL: https://youtu.be/sZp-2NQtFqA |
Th |
4 Feb. |
R, RStudio, RMarkdown |
1:00-2:20; Zoom link will be emailed |
M |
8 Feb. |
Assignment due |
- |
Tu |
9 Feb. |
Working with site x species data |
Click on
this link for notes YouTube URL: https://youtu.be/fftppBYyexE |
Th |
11 Feb. |
Working with site x species data |
1:00-2:20; Zoom link will be emailed |
M |
15 Feb. |
Assignment due |
- |
Tu |
16 Feb. |
Working with site x environment data |
Click on
this link for notes YouTube URL: https://youtu.be/sCmXMKHAE9s |
Th |
18 Feb. |
Working with site x environment data |
1:00-2:20; Zoom link will be emailed |
M |
22 Feb. |
Assignment due |
- |
Tu |
23 Feb. |
Patterns in community data |
Click on this link for notes YouTube URL: https://youtu.be/oZsaNU-YXCw |
Th |
25 Feb. |
Patterns of species occurrence and abundance |
1:00-2:20; Zoom link will be emailed |
M |
1Mar. |
Assignment due |
- |
Tu |
2 Mar. |
How do I describe the structure of a community? (part 1 of 2) |
Click on this link for notes YouTube URL: https://youtu.be/7eXgEwbERVs |
Th |
4 Mar. |
Diversity indices
|
1:00-2:20; Zoom link will be emailed |
M |
8 Mar. |
Assignment due |
- |
Tu |
9 Mar. |
How do I describe the structure of a community? (part 2 of 2) |
Click on this link for notes YouTube URL: https://youtu.be/awN2ks75AP0 |
Th |
11 Mar. |
Abundance |
1:00-2:20; Zoom link will be emailed |
M |
15 Mar. |
Assignment due |
- |
Tu |
16 Mar. |
How do I measure other dimensions of biodiversity? |
Click on this link for notes YouTube URL: https://youtu.be/qmGAG4ToJVY |
Th |
18 Mar. |
Phylogenetic and functional diversity |
1:00-2:20; Zoom link will be emailed |
M |
22 Mar. |
Assignment due |
- |
Tu |
23 Mar. |
How do I summarize complex relationships and identify the most
important patterns from a near-infinite number of possible
arrangements of multivariate data? |
Click on this link for notes YouTube URL: https://youtu.be/LAv_2j0eK6I |
Th |
25 Mar. |
Ordination |
1:00-2:20; Zoom link will be emailed |
M |
29 Mar. |
Assignment due |
- |
Tu |
30 Mar. |
How do I identify the most important variables driving patterns in a large dataset of correlated variables (and then use those variables in other analyses)? |
Click on this link for notes YouTube URL: https://youtu.be/Wqa7_18jf5A |
Th |
1 Apr. |
PCA, RDA |
1:00-2:20; Zoom link will be emailed |
M |
5 Apr. |
Assignment due |
- |
Tu |
6 Apr. |
How can I determine which environmental variables are associated
with species occurrences at different sites? (part 1 of 2) |
Click on this link for notes YouTube URL: https://youtu.be/l3Rp3uiqFqw |
Th |
8 Apr. |
NMDS |
1:00-2:20; Zoom link will be emailed |
M |
12 Apr. |
Assignment due |
- |
Tu |
13 Apr. |
How can I determine which environmental variables are associated
with species occurrences at different sites? (part 2 of 2) |
Click on this link for notes YouTube URL: https://youtu.be/raPTZtjyNos |
Th |
15 Apr. |
CCA |
1:00-2:20; Zoom link will be emailed |
M |
19 Apr. |
Assignment due |
- |
Tu |
20 Apr. |
How do I determine whether my data are grouped? |
Click on this link for notes YouTube URL: https://youtu.be/Y-ZGHA2GZ3g |
Th |
22 Apr. |
Cluster analyses |
1:00-2:20; Zoom link will be emailed |
M |
26 Apr. |
Assignment due |
- |
Tu |
27 Apr. |
If I have communities with a priori groupings, how do I
determine whether those groups are valid? |
Click on this link for notes YouTube URL: https://youtu.be/y7e8FJPjKe4 |
Th |
29 Apr. |
DFA via CART |
1:00-2:20; Zoom link will be emailed |
M |
3 May |
Assignment due |
- |
Tu |
4 May |
No class |
No class |