Question

Considering the phylogeny of the extant orders of sharks to the left answer questions 1-3. 1. If shark orders H, F, C, and A are collectively considered the "cool sharks." what type of group are the cool sharks? A. Monophyletic B. Paraphyletic C. Polyphyletic D. Cooliphyletic E. None of the above 2. Which of the groups labeled on the tree is the outgroup? A. A B. G C. Rays E. None of the above 3. Which of these statements is true? A. G is more ancient than E B. H and E are sister taxa. C. A is more advanced than all of the other groups. D. B is more closely related to A than D. E. None of the above statements are true 4. With only the information provided in the tree to the right. Which of the following statements is true? A. Reef sharks are older than Newts. B. Reef sharks gave rise to Newts. C. The common ancestor of Goldfish and Humans lived before the common ancestor of Birds and Humans. D. Reef sharks and Goldfish have no common ancestor. E. Birds are older than humans.

Answer 1

1) The shark orders H, F, C and A are known as paraphyletic groups (option c). They are called paraphyletic because have a common ancestor but many monophyletic groups come in between.

2) The outgroup of the given phylogenetic tree is Rays (option c).