The species that have had proportionally the most time to diverge are:

Question

A. R and D
B. F and Z
C. A and Z
D. F and R
E. F

Clarify Question
1. What is the key concept addressed by the question?
2. What type of thinking is required?
3. What key words does the question contain and what do they mean?

Gather Content
1. What do you know about relatedness based on a phylogenetic tree?How does it relate to the question?

Consider Possibilities
1. What other information is related to the question? Which information is most useful? Which lines connecting two species are the longest?

Choose Answer
1. Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?

Reflect on Process
1. Did your problem-solving process lead you to the correct answer? If not, where did the process break
down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

B. F and Z

Clarify Question
1. The question is about interpreting phylogenetic trees.
2.This question is asking for you to apply the principles of a
phylogenetic tree to infer the most distant common ancestor.
3. Time to diverge refers to the most time elapsed since the species had a common ancestor.

Gather Content
1. The Y-axis reflects the amount of time since two species had a common ancestor. The common ancestors are indicated by the branch points.

Consider Possibilities
1. R and D have a common ancestor at branch point 6,
this is the shortest of the links between two species. So these species had the shortest time to diverge.

Choose Answer
1. Using the logic above the two species with the longest time to diverge are F and Z with a common ancestor at branch point 12.

Reflect on Process
1. This question asked you to apply your understanding of a phylogenetic tree to determine which species had the most time to diverge.If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you realize that the Y axis (vertical) represents time and the numbers at the branch points represent common ancestors?