1. a. 40 million years ago
b. The common ancestor of all modern bears lived approximately 40 million years ago, as indicated by the branching point on the phylogenetic tree.
c. The statement is incorrect. The tree shows that Red Pandas diverged from the lineage leading to other bears around 40 million years ago, while the common ancestor of Brown Bears and Polar Bears lived much more recently (around 5 million years ago). Therefore, Red Pandas are not more closely related to Brown Bears than to Polar Bears; they are equally distant from both, sharing a more ancient common ancestor.
Parent Tip: Review the logic above to help your child master the concept of phylogenetic tree worksheet answers.