Problem:

Question 1: Imagine a different system in which toads had a wide range of variation in color. In some ponds, most of the toads are light in color. In other ponds, the average color is fairly dark. Select all of the options below that represent TESTABLE hypotheses that could explain this difference in coloration.

a.) A predator that is present in some ponds prefers one color to the other.

b.) Female toads in some ponds prefer darker toads, while females in another pond prefer lighter toads.

c.) Toad color is determined by food quality, which varies pond to pond.

d.) Toads can change their color, based on their stress level.

Question 2: An evolutionary biologist studying the toads in Question 1 hypothesizes that female toads prefer like-colored mates, and this preference maintains observed variation in toad color among ponds. Such mating is called assortative; in this case it would mean that light-colored females prefer light-colored males, and dark-colored females prefer dark-colored males.

The biologist has already determined that color is highly heritable for these toads. She rears toads in experimental tanks with no predators, over many generations, holding food quality constant. Which observation below best REFUTES her hypothesis?

a.) A tank initially containing light and dark toads of both genders eventually contains only dark toads.
b.) A tank initially containing light-colored females and males of both colors eventually contains only dark toads.
c.) A tank initially containing dark-colored females and males of both colors eventually contains only dark toads.
d.) A tank initially containing light-colored females and dark-colored males eventually contains toads of intermediate coloration.

Please provide correct option ande explain your answer.