Disruptive selection is a type of natural selection that favors extreme phenotypes over intermediate ones. In the case of limpets, disruptive selection can be observed in their shell pattern. The correct answer, option D, states that intermediate colored limpets were preyed upon. Let's delve into the explanation behind this.

Shell patterns in limpets

Limpets are marine gastropods that possess a shell on their back. The shell pattern of limpets can vary in color, ranging from light to tan to dark. This shell pattern is influenced by both genetic factors and environmental factors.

Disruptive selection

Disruptive selection occurs when extreme phenotypes have a higher fitness compared to intermediate phenotypes. In this case, limpets with extreme shell colors (either light or dark) have a higher chance of survival and reproductive success compared to limpets with intermediate shell colors (tan).

Prey selection

The key to understanding why intermediate colored limpets are preyed upon lies in their ability to blend with the environment. Limpets with light-colored shells are better camouflaged against a light-colored background, such as sandy or rocky shores. On the other hand, limpets with dark-colored shells are well-camouflaged against a dark-colored background, such as areas with algae or seaweed.

Intermediate colored limpets as prey

Limpets with tan-colored shells, which fall between the light and dark extremes, do not have a strong advantage in either light or dark environments. They do not blend well with their surroundings, making them more visible to predators. As a result, these intermediate colored limpets are more likely to be preyed upon compared to their light or dark-colored counterparts.

Conclusion

The disruptive selection observed in the shell pattern of limpets shows that extreme phenotypes (light and dark colored) have a higher fitness, while intermediate phenotypes (tan-colored) are less favored. This is because the extreme phenotypes are better suited to their specific environments and have a higher chance of survival and reproductive success. Hence, option D correctly identifies that intermediate colored limpets were preyed upon, illustrating disruptive selection.