Question 21

Manton believed that the shared characteristics are a good indication that all three groups of arthropods descended from segmented worms.

Manton's perspective suggests that while the arthropod groups have evolved independently, the presence of shared characteristics like jointed exoskeletons indicates a common ancestry linked to soft-bodied segmented worms.

A) The shared characteristics are not all present in any single ancestor of these three arthropod groups.

This option misinterprets Manton's views. He acknowledged that the shared characteristics do suggest a common ancestry, even if they evolved independently. Thus, it is not accurate to say that these characteristics are absent in any single ancestor.

B) The shared characteristics could be used to determine which of these three arthropod groups gave rise to the other two.

Manton did not propose that the shared characteristics could clarify the lineage or determine a direct evolutionary path among the groups. Instead, he emphasized their independent evolution while still linking them to a common ancestor, making this option incorrect.

C) The shared characteristics are a good indication that all three groups of arthropods descended from segmented worms.

This option aligns with Manton's argument about the evolutionary history of arthropods. He believed that although these groups evolved independently, their shared traits suggest a common origin related to segmented worms.

D) The shared characteristics are the most compelling evidence to date for the theory of convergent evolution.

While Manton acknowledged convergent evolution, he did not claim that the shared characteristics were the most compelling evidence for this theory. He maintained that these traits indicated a common ancestry, thus making this statement misleading.

E) The shared characteristics do not justify classifying all three animal groups as arthropods.

This option contradicts Manton’s position. He recognized that despite their independent evolution, the shared characteristics support classifying them as arthropods rooted in a common lineage.

Conclusion

Manton's assertion that the shared characteristics of arthropods indicate a descent from segmented worms highlights the complexity of evolutionary relationships. While he recognized convergent evolution, he emphasized that the shared traits are indicative of a common ancestry rather than independent developments. Therefore, Option C is the only one that accurately reflects Manton's views, while all other options misinterpret or misrepresent his conclusions.