Define the Prisoner’s Dilemma and describe the major differences between it and the Prisoner’s Delight. (5 pts)2. In addition to Tinbergen’s questions, we focused heavily on placing animal behavior in an evolutionary context. In this case, we often made the assumption that the behaviors we observe now are currently adaptive. However, there is the possibility that the environment has changed so that such behaviors are no longer adaptive. We call this phenomenon (where traits that were likely adaptive in the evolutionary past are no longer adaptive) an evolutionary trap. Provide an example of a behavior that may be an evolutionary trap, and explain why. Your answer must include a description of the behavior, the selective pressure that produced the behavior in the past, why it was adaptive then, what has happened to the selective pressure, and why it is no longer adaptive now. Your behavior may be a real example or hypothetical, but must be thoroughly explained.Hint: think about what selective pressures may lead to certain behaviors, and what happens when those selective pressures change or are eliminated – may be helpful to think about the last three lectures!3. Sentinel behavior is a potential behavioral phenotype that can evolve when animals live in groups. Sentinels watch for predators and give alarm calls. In some systems, sentinels give quiet vocalizations while on guard (“watchman’s song”). It is hypothesized that this song lets the group know that someone is on duty and the group is safe.Hollén, Bell, and Radford (2008) tested this hypothesis in pied babblers (left). They played either a pre-recorded babbler “watchman’s song” or background noise with the song removed and measured number of head ups per minute (vigilance) and biomass intake (successful foraging). Their major results are shown here. Based on these results, answer the following questions.(I’VE ATTACHED THE GRAPH IN PIC)A)Explain the results shown on these graphs in your own words. (5 pts)B)Describe two predictions based on the original hypothesis. Do these results support the hypothesis? If so, why, and if not, why not? (10 pts)C)Which benefit(s) of group living (if any) are shown here? (5 pts)D) Can sentinel behavior be considered altruism? Why or why not? (10 pts)
