What information is given about great whites in this section? How is this important?

The great white swims furtively in the water--its dark top matches the sea and from beneath, its white underbelly blends with the sun. The great white, barely altered through the ages, has been swimming in the waters since the Age of Reptiles. The great white is rare and sits atop the food chain. The ocean would indeed be a dangerous place if the species was plentiful. This information is important because it explains how adapted the shark is to its environment and how easily it could quickly take down a human or other weaker animal.