The diagram below represents the bones of the forelimbs of t…
The diagram below represents the bones of the forelimbs of two animals alive today that most likely evolved from a common ancestor. Members of the original ancestral population were isolated into two groups by natural events. The top structure shows a forelimb with a single long bone on the left, followed by two parallel bones in the middle section, then a cluster of small bones, and ending with several elongated bone segments extending to the right. The bottom structure shows a similar arrangement with a single long bone on the left, two parallel bones in the middle section, a cluster of small bones, and bone segments at the end, but with a different overall shape and proportions. The top forelimb appears more horizontal and elongated, while the bottom forelimb has a more curved appearance with the bone segments angled downward. If these two animals did have a common ancestor, which statement would best explain why there are differences in the bones?