One One

2

Evolution:
Why Are There So Many Living Things?
Nothing in biology makes sense except in the light of evolution. —Theodosius Dobzhansky, 1973

Chapter opening photo
Darwin’s theory of evolution is the major cornerstone of modern biology.

Overview
Evolution is one of the most important concepts in all of science. In biology, it has become a Unifying Principle, a concept of such central importance that nearly all other facets of the field are directly related to it and influenced by it. The above quote by the American geneticist Dobzhansky captures the esteem with which most biologists hold evolution. For over 150 years, the concept of evolution has stimulated vast controversy. Most disagreements have 19

20 CHAPTER 2 Evolution: Why Are There So Many Living Things? come from nonscientists who have examined evolution in the light of their own fields. Some found it useful to adopt parts of the concept out of context. For example, some politicians and economists have focused on one precept of evolution, “survival of the fittest,” to justify big countries or companies gobbling up little ones. As we shall see, survival of the fittest is not synonymous with ruthlessness. Sometimes the least conspicuous individuals are the ones most likely to survive. Others have found the theory of evolution disturbing to their belief in a higher order. Theologians and philosophers seem split in their opinions of the theory; some see no conflict and can accept evolution easily, while others find it more difficult to do so. Interesting as these controversies are, they are distracting to our purpose. Keep in mind that evolution is a biological theory. It was not intended to be useful outside of science. When the theory of evolution was first proposed, it also sparked controversy within science and even within biology. Disagreements were particularly keen. This may be surprising in light of what we learned in the first chapter. There we described a series of orderly,... [continues]

Read full essay