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Class 9, October 21:


Evolution and function of acoustic signals:


Learning outcomes:


1. You will be able to describe evolutionary mechanisms that lead to the origin and maintenance of acoustic communication systems.


2. You will be able to summarize the major functions of acoustic signals, the information contained in those signals and how the honesty of that information is maintained.










Read the book scans above and use Piazza ( to answer the following thought questions (due Tuesday Oct 20 before midnight). We will discuss your answers to these questions in class:



1. After reading the first six pages of the Searcy and Nowicki reading (chapter 1), use the information in the chapter to give one example of an acoustic signaling exchange between two animals that would be an “honest/reliable” signaling interaction and one example that would be a “deceitful” signaling interaction. Be sure to include all of the important components of the authors’ definition of honesty and deceit in signaling: characteristics of a signal, information contained in the signal, benefit to sender, response of receiver and benefit to receiver.


2. Use the information in chapter 1, fill out the following list so that honest signals, cues, deception and ignoring/spite are in the correct places:


Benefit to receiver     Benefit to sender

Positive                        Neutral or negative  =

Positive                        Positive                   =

Neutral/negative          Positive                   =



3. After reading the remaining chapter summaries/examples in the Searcy and Nowicki book and the summary of chapter 10 in Bradbury and Vehrencamp, write a list that summarizes the major functions of signals (focus on the functions described by Searcy and Nowicki, rather than the broad categories described by B&V). For each, describe what you expect would maintain signal honesty and give an example of an animal that uses an acoustic signal for this function. Include a brief description of the signal the animal uses and the context.




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