Communication and Defense

Problems/Case Studies

"My Brother’s Keeper: A Case Study in Evolutionary Biology and Animal Behavior" Kari Benson, Lynchburg College. State University of New York at Buffalo’s National Center for Case Study Teaching
In this interrupted case, students work in teams to interpret behavioral data with respect to evolutionary biology, specifically the behavior of alarm calling in a certain type of ground squirrel, which was first reported by Paul Sherman in Science in 1977.
The case is appropriate for use in animal behavior, ecology, evolutionary biology, or introductory biology courses.

"Conversations with Fireflies: A Case Study of Mimicry and Defense". Lisa Carloye, Elon University. State University of New York at Buffalo’s National Center for Case Study Teaching
This case explores the aggressive mimicry behavior of the femme fatale firefly - female fireflies in the genus Photuris that mimic the flash pattern of females in the genus Photinus in order to lure Photinus males to their death. The case consists of a story featuring entries in an old field notebook that are based on the research of J.E. Lloyd, originally published in Science in 1965, as well as a series of handouts that the instructor presents to the students for analysis and discussion in class in a progressive disclosure format.
This case is appropriate for use in high school and undergraduate general biology, ecology, and zoology courses.

"A Birdsong Trilogy".   DE Allen.  Thinking Toward Solutions:  Problem-Based Learning Activities for General Biology.  Allen, D. E. and Duch, B. J. (1998).   New York:  Saunders College Publishing, pp 140-148. 

The narrative discusses the process of formulating scientific hypotheses and why birds sing.  Students have two opportunities to practice making hypotheses and decisions.

"What’s the attraction here?"- Cattle egret became plentiful in North America by 1972.  Egrets are small white birds that associate with much larger animals such as cattle, or buffalo and elephants in African egrets.  Students make predictions and accumulate evidence for the egret behavior.

"How does a turkey vulture find road-kill?"  Two hypotheses are presented, following scent or using vision.  Students create new hypotheses and must test a hypothesis setting up the experiment including the observations one would make and how data would be recorded. Students then evaluate the research as to whether taxpayers should fund biological experiments.  This summarizes the skills needed for scientific process.

CNN Video Clips


Topic: "Dolphin Sixth Sense": Biology 8th Ed. CNN Ed 2004 (1:04)
Researchers are studying the ability of dolphins to use echolocation. The animals emit sound waves and derive information about their environment by analyzing the sound that bounces back. Captive dolphins can be trained to use echolocation to identify objects hidden behind a screen. Using this method, scientists demonstrated that dolphins can discriminate between two otherwise identical cylinders that differ by a millimeter in their wall thickness. The study is described in the 7 August 2003 issue of Nature. (Student worksheet provided on CD)

Topic: "Slithery stowaways":  Biology 7th Ed. CNN Ed 2003 (2:52)<>
Brown tree snakes now number in the millions on Guam.  DNA studies show all are descended from a single female snake that probably arrived via a ship.  The venomous snakes, which can reach ten feet in length, are an economic nuisance, a minor threat to humans, and a major disaster for Guam's wildlife.  Ten species of birds have been driven to extinction, and fruit bat populations are being decimated.  Efforts are underway to contain the snake to Guam; some snakes have already been intercepted at airports in Hawaii, Texas, and elsewhere.  

Topic:  "Deadly animals":  Biology 7th Ed. CNN Ed 2003 (1:48)
Animals that many consider dangerous to humans actually cause remarkably few deaths.  In the United States, there are no records of human deaths resulting from wolf attacks, although domestic dogs kill 10–20 people per year.  Sharks and alligators are a negligible threat.  Car accidents resulting from hitting deer or other large herbivores kill about 80 people per year.  Between 40 and 60 people die of allergic reactions to bee and wasp stings.  The truly deadly animals are disease-carrying insects.  Worldwide, the tsetse fly kills 66,000 per year.  The mosquito exacts the greatest toll, killing two million per year.

Topic:  "Sexy singers":  Biology 7th Ed. CNN Ed 2003 (1:56)
Male sparrows are highly territorial.  Bruce Nowicki of Duke University describes how males compete by singing.  The females seem to respond purely to a male's song.  Nowicki plays video of a female sparrow who—in response to playback of a particularly appealing recorded song—lifts her tail as if to mate.  The males must learn their song from adults.  The worksheet includes the URL for the Nowicki Lab Web site.


Topic:  "Stressed salamanders":  Biology 7th Ed. CNN Ed 2003 (3:23)

Something is affecting the salamanders that live near Cornell University's golf course.  Other populations as well as specimens gathered from the area before the golf course existed have spots that line up on either side of the body.  The population near Cornell’s golf course has asymmetrical spots.  One theory is that the salamanders are being affected by runoff of chemicals from the golf course.  The manager of another golf course defends the course and says that it promotes the health of wildlife.  He suggests that other factors, such as drought, may be causing the change in spotting.

Articles

“Our Common Senses”  Maya Pines. Seeing, Hearing, and Smelling The World:  New Findings Help Scientists Make Sense of Our Senses Howard Hughes Medical Institute, 1995.
Scientists recognize more than 5 senses:  vision, hearing, touch, smell, taste, pain, pressure, temperature, join position, muscle sense, movement.  Our attention is captured by change. The history of sensation in scientific research is discussed.  Simple diagrams of receptor cells for each of the senses are featured.   <>

“A Language that the Brain can Understand” Maya Pines. Seeing, Hearing, and Smelling The World:  New Findings Help Scientists Make Sense of Our Senses Howard Hughes Medical Institute,1995.
The receptor cell converts the stimulus into an electrical signal, which is the way the brain communicates.  A helpful diagram illustrates this point. A physiological explanation of sight is given. 

“Breaking the Code of Color” Geoffrey Montgomery.Seeing, Hearing, and Smelling The World:  New Findings Help Scientists Make Sense of Our Senses Howard Hughes Medical Institute,1995.
Neurons have a parallel processing structure because they are relatively slow at computing input stimulation.  A descriptive passage about rhodopsin and components of sight is given.  Descriptions of sight dysfunction are also given, as in colorblindness.  

“A Narrow Tunnel of Light”.  Montgomery, Geoffrey.  Seeing, Hearing, and Smelling The World:  New Findings Help Scientists Make Sense of Our Senses Howard Hughes Medical Institute, 1995.
Retinitis pigmentosa (RP) is a genetic disorder that causes degeneration the retina and affects sight, leaving many blind by age 40.  There is no therapy for the disease.  Errors in the rhodopsin gene cause proteins to be unstable.  A possible saving grace would be a drug that reduces energy consumption of the rod cells to save the patient’s cones.   

“How We See Things that Move”.  Montgomery, Geoffrey.  Seeing, Hearing, and Smelling The World:  New Findings Help Scientists Make Sense of Our Senses Howard Hughes Medical Institute, 1995.
An anecdote of a patient who could not see motion is given.  The motion-processing system of the brain automatically fuses images, as in the frames of a movie.  Directionality of movement is a vital component to seeing motion.  Insight into the research of seeing motion is presented. 

“The Urgent Need to Use Both Eyes” Montgomery, Geoffrey.  Seeing, Hearing, and Smelling The World:  New Findings Help Scientists Make Sense of Our Senses Howard Hughes Medical Institute, 1995.
“When you look at yourself in the mirror you are looking into a predator’s eyes.”  The need to use both eyes to survive can be severely undermined by a condition called strabismus, the failure of the left and right eye to align properly after birth.  Misalignment may also lead to amblyopia, a loss of vision without any eye defect.  Therefore, both eyes must be used.

"Chimps champs of memory". Malcolm Ritter: Post and Courier (Dec. 4, 2007) -Available in PBL resource cabinet in SCIC outside room 207
Japanese researchers conduct memory-based testing between chimpanzees and humans.