ABSTRACT
A chapter on the evolution of plants and people must begin with some understanding of the term “evolution.” Scientists can trace the origin of change over time to the Greeks, but a formal understanding had to await modernity. The nineteenth century was a time of intellectual owering in many elds, including natural history, the discipline that would become biology in the twentieth century. A number of people proposed theories of evolution. By theory, I do not mean, as is the case in popular culture, speculation or guess. I mean a logical, integrated construct of ideas that scientists may test with the aim of strengthening or refuting it. A theory is thus a powerful tool, not a wild assertion. To consider a brief example, creationists often emphasize that evolution is a theory with the expectation that the public will not take it seriously because most people erroneously believe that a theory is nothing more than a crackpot idea that scientists gin up in their spare time. Creationists thus prey upon popular misunderstandings to score points with those either hostile to or with very little training in the sciences.
