PPEM 454: Virus Ecology (Fall 2017)

In this course students will learn about the interplay among viruses, hosts and the environment. The diversity of viruses, which infect all known life forms, will be explored.


  • Plant Pathology and Environmental Microbiology


PPEM 454 Virus Ecology will provide a perspective about virology that is different from the paradigm of viruses only as agents of disease. All living entities are hosts for viruses; the presence of viruses can be detrimental, neutral, or beneficial, depending on the ecological context. Students will gain a basic understanding of the ecology of viruses: how viruses interact with their hosts and how those interactions modulate the hosts' interactions with their environment.

Course Logistics

Instructor: Dr. Marilyn J. Roossinck
Professor, Plant Pathology and Environmental Microbiology | Biology
Office: W229A Millennium Science Building
Office Hours: By appointment on Tuesdays, 1-4 p.m.

Class Meeting Times: Tues/Thurs | 10:35-11:50 a.m.
Class Location: 201 Buckhout Lab
Prerequisites: Basic course in biology (e.g., BIOL 110)

Course Goals

By the conclusion of the course, students will:

  1. Appreciate the role viruses play in the biosphere;
  2. Understand how viruses interact with their hosts in the context of host ecology and evolution;
  3. Be able to critically assess scientific literature.

Course Resources

Textbook: The OPTIONAL textbook for this course is Studies in Viral Ecology, vols. 1-2, 2011, edited by Christon J. Hurst. Two copies of these books are available on reserve for this course in the Albert C. Hildebrandt Plant Pathology Library.

Supplemental reading will be assigned with some lectures. These will be posted on the class CANVAS site.

Course Methods

The students will participate in an interactive lecture series, a virus ecology class project, class quizzes with discussion, and interpretation of scientific literature.

Participation 90
Quizzes 50
Presentation 100
Midterm exam 100
Virus Ecology Class Project 60
Final exam 100

Course Grading

Grades will be assessed on class participation, work on the virus ecology class project, quiz scores, a midterm exam, a paper presentation, and a final exam.

GradePoints Earned
A 451–500
B 401–450
C 351–400
D 301–350

Course Policies

Electronics: You may use a laptop or electronic notebook for taking notes. Please keep your cell phone turned OFF and do not text, read email, or surf the web during the class. These activities will reduce your class participation points for the day.

The class begins at 10:35 a.m. It does not begin at 10:40 or 10:45. Please be courteous to your professor and your fellow classmates and come on time. Tardiness will result in a deduction of your participation points.

Makeup exams and quizzes will be offered to students who have a legitimate excuse according to university attendance policies and must be arranged with the instructor. You must notify the professor by email, no later than 10:00 a.m. the day of the class if you have an illness/emergency that prevents you from attending any class.

Right and wrong answers: For all exams and quizzes, please answer to the best of your knowledge, but do not guess. Questions left blank will receive zero points, but questions answered wrong may receive negative points.

Course Schedule

8/22 Introductions and prior knowledge Prior knowledge assessment
8/24 1 Basics of virology and ecology 1.1 Basics of virology I Guest lecturer: R. Serge Ouédraogo
1.2 Basics of virology II Tips on reading scientific papers
8/29 1.3 Basics of ecology I
8/31 1.4 Basics of evolution I Intro to class STORY CORE PROJECT
9/5 2 Viruses and symbiosis 2.1 Viruses as symbionts Discussion
9/7 2.2 Mutualistic viruses Paper discussion
9/12 3 Virus biodiversity 3.1 Viruses in the sea - phage studies
9/14 3.2 Plant virus biodiversity Discussion
9/19 3.3 Viruses in other eukaryotes Discussion
9/21 3.4 Phage and phage ecology
9/26 3.5 Giant viruses DEADLINE FOR STORY CORE
9/28 4 Complex interactions 4.1 Adaptation to extreme environments Discussion
10/3 4.2 Plants, viruses, and insects DEADLINE FOR PRESENTATION
10/5 5 Host species invasions 5.1 Killer viruses Field trip preparation
5.2 Viruses as bioweapons
10/12 Field trip results Student presentations (2)
10/17 Continued 5.3 Viruses as regulators of host populations Student presentation
10/19 6 Fitness effects 6.1 Measuring fitness Guest lecturer Edelio Bazán
10/24 6.2 Rapid adaptation Student presentation
10/26 MIDTERM EXAM Units 1-5
10/31 7 Host ecology changes 7.1 Human viral diseases and changes in human lifestyles Student presentation
11/2 7.2 Viruses affecting other disease states Student presentation
11/7 8 Zoonotic viruses 8.1 Influenza Student presentation
11/9 8.2 Emerging viruses
11/14 9 Viruses changing hosts 9.1 Symbiogenesis Student presentation
11/16 9.2 Viruses and host evolution
11/21 HOLIDAY-no classes

11/28 10 Virus-like entities 10.1 Viroids, prions, and satellites Discussion
11/30 END-OF-TERM EXAM Units 6-10
12/5 Class project presentations
12/7 Class project presentations

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