Figure 20.1
-Using the phylogenetic tree shown in Figure 20.1,which extinct species should be the best candidate to serve as the outgroup for the clade whose common ancestor occurs at position 2?
A)A
B)B
C)C
D)D

Question

Figure 20.1
-Using the phylogenetic tree shown in Figure 20.1,which extinct species should be the best candidate to serve as the outgroup for the clade whose common ancestor occurs at position 2?
A)A 
B)B 
C)C 
D)D

Quizplus · Accepted Answer

The outgroup for a clade should be chosen based on its evolutionary distance from the members of the clade. In this phylogenetic tree, species A is the most distantly related to the members of the clade whose common ancestor occurs at position 2. This can be seen by the fact that species A is the only species that diverged before the common ancestor of the members of this clade. Therefore, species A is the best candidate to serve as the outgroup for this clade.

Figure 20.1 -Using the Phylogenetic Tree Shown in Figure 20.1,which Extinct Species