1. The modern continents include remnants of their distant history. Fossils, glaciers, and complementary coasts provide evidence of how the plates used to fit together. Plant and animal fossils tell us when and where they lived. Some forms of life “rode” across diverging plates, becoming alone and evolving into new species.

2. Divergent plate boundaries cause seafloor spreading. Heat from the mantle’s convection currents causes the crust to become more flexible and less thick as tectonic plates progressively drift apart. The less dense material rises, generating a seabed mountain or raised area. The crust eventually cracks.

3. No. Because the movement of a/the plate is natural.