Overview

Darwinian evolution, that is, evolution through the accumulation of almost undetectable changes over millions of years, has been the mainstay of evolutionary theory since its formulation by Charles Darwin (1809-1882) and Alfred Wallace (1823-1913) in the mid-nineteenth century. In the last half of the twentieth century, this view of evolution was further developed to accommodate the realization that natural selection can operate in alternate ways, that evolution does not always operate with geologic slowness, and that the fittest do not always survive. These revisions to evolutionary theory have had a profound impact on how we view the natural world and our place in it, as they serve to emphasize that there is no evolutionary "reason" for us to exist. Instead, it is becoming more obvious that humans, like any other species, are the result of a number of factors...