Lesson 6.5: Speciation
6.5.6 Formative Assessment        

Phylogenetic tree showing the relationship between extinct species of dinosaurs and modern birds.

Dinosauria cladogram by T. Michael Keesey / CC BY-NC-SA 2.0

1) Based on the tree shown, which organisms are more closely related to Megalosaurus?

        a) Struthio        b) Brachiosaurus        c) Saltasaurus        d) Stegosaurus

2) Why might a geographic barrier such as a large river cause the formation of a new species of small rodents (mice) but not a new species of birds? Describe how this meets the requirements for speciation in Mice but not birds.

3) List the two requirements for speciation to occur

a) ___________________________________________________

b) ___________________________________________________