Question

warm-up
which species is species c more closely related to?
scientists have found a new fossil and they want to know which species it is more closely related to. what is the best place to put species c on the evolutionary tree below?
evolutionary tree image with common ancestor population, species b, space 1, species a, space 2, and species c
where should species c be placed on the tree?
☐ space 1 ☐ space 2
what is one body structure you used to make your decision?
☐ skull ☐ backbone ☐ tail ☐ front limb ☐ back
explain how this body structure helped you make your decision.
handwritten notes partially visible

Explanation:

Step1: Analyze the evolutionary tree structure

The evolutionary tree shows the relationships between species. Species A and Species C have similar back limb structures (the zig - zag - like back limbs), while Species B has different limb structures. The branch containing Species A also has space 2, and the branch with Species B has space 1. Since Species C's body structure (back limb) is more similar to Species A, it should be placed in the same branch as Species A, which is space 2.

Step2: Confirm the body structure used

Looking at the body structures, the back limb structure (the shape of the back legs) is similar between Species A and Species C, while different from Species B. So we use the back limb structure to make the decision.

Answer:

• Where should Species C be placed? space 2
• What body structure? back limb (with the checkbox for back limb marked)