Q7 - Marine biologists have long

[nbayar1212]

Just did this practice test and thought I'd pitch in.

We are looking for an AC that strengthens the "new theory" mentioned in the second half of the stimulus.

From the stimulus we learn that there are two theories. One says that variation in shell color is to camouflage the snails by helping them blend into the seafloor i.e. we see more dark colored shells on dark sea floors and light colored shells when the floor is lighter.

A newer theory say that shell color is linked with physiological stress and heat absorption i.e. when there is a lot of wave action that limits the amount of heat absorbed from the sun and we have dark shells and when there is little wave action there is more heat absorption and we have light shells.

What would strengthen the new theory? If we have a situation where there are dark colored shells on a light colored sea floor with a lot of waves OR if we have light colored shells on a dark sea floor with few waves. The reason either of these work is because both would be counterexamples to the old theory but still affirm the explanation given by the new theory.

a) Says there are dark colored snails on a dark seafloor but this would strengthen the old theory since it makes it likely that the shell color is to camouflage.

b) Weaken the new theory since we have dark colored shells even though the water is calm (the stimulus tells us that this would lead to light colored snails)

c) Weakens the new theory since when we have a lot of wave action we would expect to see dark colored shells

d) Yes! we have light colored snails when the water is calm (as the new theory predicts) and its in a situation where the old theory would have predicted that the snails would have dark colored shells,

e) This AC does not help us pick the new theory over the old one since we have light colored shells on a light colored sea floor (as the old theory predicts) AND with calm waves (which the new theory predicts would lead to light colored shells)

[ManhattanPrepLSAT1]

Great explanation nbayar1212!