ABSTRACT
In a certain species of highly territorial fish, there are two distinct subspecies. Call a fish from the more aggressive subspecies a “Hawk” and call a fish from the less aggressive subspecies a “Dove”. When two fish meet, they compete over a territory, and their behaviors are determined by which of the two subspecies they belong to. We assign scores in this competition in a way that models how likely a fish is to survive the season and reproduce. When a Hawk meets a Dove, the Dove flees and the Hawk wins the territory. Consequently, we award the Hawk 10 fitness points, and award 0 to the Dove. When two Doves meet, they both initially flee. However, seeing the territory empty, one of the Doves inevitably returns and successfully occupies it. To model this, we award each of the Doves 5 points, indicating that on average each Dove has a 50% chance of earning 10 fitness points for occupying the territory. Finally, when a Hawk meets a Hawk, the fight that ensues is likely to injure both fish. These injuries are so severe that we award each of the Hawks −10 points.
