FOREWORD

      The theory of biological evolution is the central organizing principle of modern biology. In 1973, the eminent evolutionist Theodosius Dobzhansky famously asserted, “Nothing in biology makes sense except in the light of evolution.” Evolution provides a scientific explanation for why there are so many different kinds of organisms on Earth and gives an account of their similarities and differences (morphological, physiological, and genetic). It accounts for the appearance of humans on Earth and reveals our species's biological connections with other living things. It provides an understanding of the constantly evolving bacteria and viruses and other pathogenic organisms, and it enables the development of effective new ways to protect ourselves against the diseases they cause. Knowledge of evolution has made possible improvements in agriculture and medicine, and has been applied in many fields outside biology—for example, in software engineering, where genetic algorithms seek to mimic selective processes; and in chemistry, where the principles of natural selection are used for developing new molecules with specific functions.

      Yet, in the United States, many people reject the scientific knowledge concerning evolution, mostly for religious reasons. According to a Gallup poll of 1,016 U.S. adults, taken in November 2004, 45 percent of those surveyed favored the statement “God created human beings in their present form within the last 10,000 years.” Thirty-eight percent favored “Man developed over millions of years, but God guided the process,” and 13 percent favored “Man developed over millions of years from less advanced life forms.” Teaching creationism rather than evolution in the schools is favored by a large number of American citizens. In a CNN/USA Today Gallup poll of 1,001 adults conducted in March 2005, 76 percent would not “be upset if public schools in [their] community taught creationism,” but only 63 percent would not “be upset if the schools taught evolution.” Only 22 percent would be upset if creationism was taught, while 34 percent would be upset if evolution was taught. Other polls yield similar statistics.

      Are evolution and religion—or, more generally, science and religion—in contradiction.? No. In fact, if they are properly understood, science and religion cannot be in contradiction, because science and religion concern different aspects of the human experience. Science and religion are like two different windows for looking at the world. Both look at the same world, but they show different aspects of that world. Science encompasses the processes that account for the natural world: how planets move, the composition of matter and the atmosphere, the origin and adaptations of organisms, and so on. Religion concerns the meaning and purpose of the world and of human life, the proper relation of people to the creator and to each other, the moral vales that inspire and govern people's lives, and more. Apparent contradictions emerge only when either the science or the beliefs, or often both, encroach into one another's subject matter.

      Scientific explanations are based on evidence drawn from examining the natural world, and they rely exclusively on natural processes to account for natural phenomena. Scientific explanations are subject to empirical tests by means of observation and experimentation and are subject to the possibility of modification and rejection. Religious faith, in contrast, does not depend on empirical tests and is not subject to the possibility of rejection based on empirical evidence. The significance and purpose of the world and human life, as well as issues concerning moral and religious values, are of great importance to many people, perhaps a majority of humans, but these are matters that transcend science.

      To some people of faith, geology, astronomy, and the theory of evolution are incompatible with their religious beliefs because scientific knowledge is inconsistent with the creation narrative in the book of Genesis and other biblical texts. A literal interpretation of Genesis is indeed incompatible with the gradual evolution of humans and other organisms by natural processes. But that incompatibility emerges only when religious tenets transgress their proper domain. Most biblical scholars and theologians do not consider the Bible to be an elementary textbook of geology, astronomy, or biology; rather, they seek in the Bible religious truths about the meaning and purpose of life and about moral and other spiritual values.

      Charles Darwin (1809-1832) is deservedly credited