The Science of Marine Biology Marine biology is the scientific study of the organisms that live in the sea. The ocean is a vast realm, home to countless strange and wonderful creatures. It is often the beauty, mystery, and variety of life in the sea that attract students to a course in marine biology. Even professional marine biologists feel a sense of adventure and wonder in their studies. There are also many practical reasons to study marine biology. Life on earth probably originated in the sea, so the study of marine organisms teaches us much about all life on earth, not just marine life. In the late nineteenth century, for example, the Russian scientist Ilya Metchnikoff discovered cells of the animal immune system by studying sea anemones and the larvae of sea stars. His discovery underpins a great deal of modern medical research. Marine life also represents a vast source of human wealth. It provides food, medicines, and raw materials; offers recreation to millions; and s...