What happened during the cambrian explosion? a. early chordates began to appear. b. many groups of vertebrate animals became extinct. c. groups of dinosaurs began to evolve into the ancestors of modern birds. d. animals evolved a variety of complex body plans.

Found evidence that the continents were joined together at one time.

Environmental impacts on evolution : mastery test

1) what three conditions must be present for minerals to form through natural processes? 2) why are minerals considered inorganic substances? 3) how do oxides differ from other minerals that contain oxygen atoms? 4) how is a sulfide different from a sulfate? what makes native elements unique?