1. 4 This book is organized to help you learn biology Core Principles you will examine evolution, the gradual change in popula of biolog tions from one generation to the next, which has led through natural selection to the biological diversity we see around us. Finally, at the community and ecosystem levels organizing principle has emerged: biological diversity re- you will study ecology, which deals with how organisms in- flects history, a record of success, failure, and change ex- teract with their environments and with one another to pro- tending back to a period soon after the formation of the earth. The explanation for this diversity, the theory of evo- earth lution by natural selection, will form the backbone of your study of biological science, just as the theory of the covalent Organisms bond is the backbone of chemistry, or the theory of quan- The second half of the book is devoted to an examination of that of tion is a thread that runs through everything you will learn organisms, the products of evolution. It is estimated that at in this book. east 5 million different kinds of plants, animals, and micro- organisms exist, and their diversity is incredible(figure 1. 13) Later in the book, we will take a particularly detailed look at Basic principles the vertebrates, the group of animals of which we are mem- The first half of this book is devoted to a description of the bers. We will consider the vertebrate body and how it func- basic principles of biology, introduced through a levels-of- tions, as this information is of greatest interest and impor organization framework(see figure 1.2). At the molecular, tance to most students troduced to cell biology. You will learn how cells are con- structed and how they grow, divide, and communicate.At As you proceed through this book, what you learn at one the organismal level, you will learn the principles of genetics, stage will give you the tools to understand the next. The hich deal with the way that individual traits are transmit core principle of biology is that biological diversity is the ted from one generation to the next. At the population level, esult of a long evolutionary journe Plantae Animalia Eubacteria FIGURE 1.13 The diversity of life. Biologists categorize all living things into six major groups called kingdoms: archaebacteria, Archaebacteria eubacteria, protists, fungi, pla Chapter 1 The Science of Biology 17Chapter 1 The Science of Biology 17 Core Principles of Biology From centuries of biological observation and inquiry, one organizing principle has emerged: biological diversity re￾flects history, a record of success, failure, and change ex￾tending back to a period soon after the formation of the earth. The explanation for this diversity, the theory of evo￾lution by natural selection, will form the backbone of your study of biological science, just as the theory of the covalent bond is the backbone of chemistry, or the theory of quan￾tum mechanics is that of physics. Evolution by natural selec￾tion is a thread that runs through everything you will learn in this book. Basic Principles The first half of this book is devoted to a description of the basic principles of biology, introduced through a levels-of￾organization framework (see figure 1.2). At the molecular, organellar, and cellular levels of organization, you will be in￾troduced to cell biology. You will learn how cells are con￾structed and how they grow, divide, and communicate. At the organismal level, you will learn the principles of genetics, which deal with the way that individual traits are transmit￾ted from one generation to the next. At the population level, you will examine evolution, the gradual change in popula￾tions from one generation to the next, which has led through natural selection to the biological diversity we see around us. Finally, at the community and ecosystem levels, you will study ecology, which deals with how organisms in￾teract with their environments and with one another to pro￾duce the complex communities characteristic of life on earth. Organisms The second half of the book is devoted to an examination of organisms, the products of evolution. It is estimated that at least 5 million different kinds of plants, animals, and micro￾organisms exist, and their diversity is incredible (figure 1.13). Later in the book, we will take a particularly detailed look at the vertebrates, the group of animals of which we are mem￾bers. We will consider the vertebrate body and how it func￾tions, as this information is of greatest interest and impor￾tance to most students. As you proceed through this book, what you learn at one stage will give you the tools to understand the next. The core principle of biology is that biological diversity is the result of a long evolutionary journey. 1.4 This book is organized to help you learn biology. Plantae Animalia Fungi Eubacteria Archaebacteria Protista FIGURE 1.13 The diversity of life. Biologists categorize all living things into six major groups called kingdoms: archaebacteria, eubacteria, protists, fungi, plants, and animals