Biology: The Science of Life [antikvár]

It is an old cliché that the world becomes smaller every day, but it is nonetheless true. As the numbers of human beings living on the earth increase, and as their technological capabilities expand, their acts have increasingly serious consequences that affect more and more persons. This is true on any level—family, local, or national. The decision of a family to have one more child can affect the neighboring families as well as the one producing that child: the decision of a city on how to dispose of garbage or sewage can affect neighboring cities: the decision of a country to build a dam may affect a neighboring country; and all these decisions affect future generations. Nearly all the habitable regions of the earth now are called home by some people, and there are few places one can go to escape the pollutants produced by his fellow man. The only escape today is to search for the solutions to these problems rather than to avoid them. This book does not solve these problems. However, the students of today, who will be the voters and leaders of tomorrow, will have a hand in solving them. To do so intelligently they must have some basic knowledge about the biological nature of man and the animals and plants with which he shares this planet and on which he depends for his continued existence. Most of the voters of tomorrow, however, will not be biology majors. Most of them will take perhaps only one biology course during their college years. This book is aimed at such students. Wherever possible, the introduction of technical terms has been avoided. The student may not believe it, but his instructor will. Rather, the emphasis is on principles—how things work and how they are interrelated in a functional way. For this reason the book contains no detailed phylogenetic material. An outline of the living world in the appendix gives some idea of the diversity of living things but gives little indication of their evolutionary relationships. Each chapter begins with a list of statements that give the reader a preview of the material to follow. The textual material expands on the material summarized in the statements. This approach is used because it has been the experience of the author that many students, especially the non-science majors, too often fail to see the forest for the trees. Perhaps it is because we have pointed out too many facts to be memorized and the student loses interest in the generalities and theories based on those facts. For this reason each chapter of the book begins with generalities and proceeds to details. Many of the chapters can stand independently of each other. This allows the instructor flexibility in assigning reading material to students and should permit him to follow his own preferred schedule. I would like to thank the following persons who read part or all of the manuscript during its preparation and to whom I am grateful for guidance and suggestions; VII