"You have been asked to study two recently discovered fish species, both found in waters off a small island. The two species are very similar in general structure, but there are two key differences between them. In species A, males are brightly patterned with blue, red, and purple scales, whereas the females are drab, and males are much larger than females. In species B, males and females are the same size, and both are a dull brown color that blends in with the sandy bottom. You have decided to do an in-depth study of these two species. In order to get your research grant, you must first develop some predictions about what you will find."
After you read this scenario, I would like for you to answer the following questions:
a. What differences in behavior do you predict (list as many as you can think of)?
b. How might the evolutionary histories of the two species differ?
From an evolutionary perspective at one point, diversity was required. Perhaps there was flora that grew that was blue, red and/or purple so that it would not stand out too much for predators to see, while at the same time drew attention to the female fish. The smaller female ...
The issues of color, diversity and selection for breeding are discussed in a hypothetical situation on an island.