Question

Scientists have debated the evolution of three life forms: reptiles, birds and dinosaurs. After many years of reviewing fossil records scientists proposed the evolutionary relationship seen above in the cladogram. Using radiometric dating scientists added a time frame for the evolution of the animals within the model. Based on this new information, what prediction can we make about the animals represented here? MYA refers to millions of years ago. A) Dinosaurs were the last to evolve among these groups of animals. B) Crocodiles are the most highly evolved of the animals represented here. C) Dinosaurs lived and became extinct before the arrival of lizards and snakes. D) Turtles were the first group of animals to branch off in this tree of animals.

Answer 1

D) Turtles were the first group of animals to branch off in this tree of animals.

Turtles were the first group of animals to branch off in this tree of animals. According to the tree, the animals share a common ancestor. The first branch shows that what we call a speciation event occurred, resulting in two lineages. The first group of animals to result were the turtles. All the other animals are on the other branch. This does not indicate that any group is more highly evolved than the other.