Life and Its Molecules: A Brief Introduction

derstand some of the basic concepts and terminology of molecular biology. This article is a brief introduction to the extraordinarily complex phenomenon of life and to its molecular basis. We begin with the amazing diversity of life forms and the equally amazing unity in the molecules underlying life’s processes. The challenge of accounting for both the variety and the commonalities among organisms is met by evolutionary theory; despite controversies, all scientific approaches to understanding life build on a shared core that can briefly be stated. One of the great insights of the last generation of biologists was the chemical instantiation of these evolutionary theories, whose discovery has driven biology toward the study of the structure and function of biological molecules. After an introduction to some of these key molecules and to the central dogma of molecular biology, we can begin to see the outlines of how such molecules can accomplish the tasks required of simple and then more complex life forms. The introduction concludes with a brief account of some of the new instruments and model systems that are now so rapidly advancing scientific understanding of life.