Question

When originally classified, whales and hippopotamuses were placed into different orders.
Molecular analysis recently suggested that whales (order Cetacea) and hippopotamuses (order Artiodactyla) are extremely closely related, sharing a recent common ancestor.
This has led some taxonomists to create a new phylogenetic tree that puts the two orders together into a single clade. It is still unclear as to whether the whales diverged from Hippopotamuses before or after the divergence of other species in the order Artiodactyla.
When analyzing the two new possible phylogenetic trees above, which of the following is an accurate inference?

• A. Clade Option B shows that Llamas are more recently related to Hippopotamuses than is shown in Clade Option A.
• B. Clade Option A shows that Llamas are more closely related to Hippopotamuses than are Whales.
• C. Clade Option A shows that Llamas are more closely related to Whales than they are to Hippopotamuses.
• D. In Clade Option B, all the artiodactyls (Hippopotamus, Llamas, and Giraffes) are more closely related to each other than any are related to Whales.

Answer 1

Answer: (B)

Clade Option A shows that Llamas are more closely related to Hippopotamuses than are Whales.

Llamas are more closely related to Hippopotamuses in Clade option A than in B. In clade option B, they have diverged most primitively. Clade Option A shows that Llamas are more closely related to Hippopotamuses than are Whales because whales diverged earlier than Llamas. In Clade Option B, Llamas and Giraffes) are more closely related to each other. However, Hippopotamus is more related to whales than other two artiodactyls.

Thus, the correct answer is 'Clade Option A shows that Llamas are more closely related to Hippopotamuses than are Whales.'