Evolution is a fact: of that there can be no dispute. But, writes Richard Morris in this lively overview of modern biology, scientists have been arguing about most other aspects of Darwinian thought for generations, and the battle is growing ever fiercer with the advent of “evolutionary psychology” and other new approaches.
Following the biologist Ernst Mayr, Morris identifies at least five subtheories in the theory of evolution: “evolution as such,” or the idea that evolution takes place at all; “common descent,” the notion that all life originated in a common ancestor; “multiplication of species,” or the splitting of one species into two or more species over time; “gradualism,” the idea that evolutionary change happens slowly over a long period of time; and “natural selection,” the idea that favorable genetic characteristics prevail over less desired ones. These subtheories are widely debated these days, with controversial scientists such as Stephen Jay Gould advancing ideas of “punctuated equilibrium,” whereby change happens suddenly and often catastrophically; Gould’s nemesis Richard Dawkins advancing orthodox Darwinism under the “selfish gene” metaphor; and other scientists turning up bits and pieces of evidence of environmental determinism and parallel evolution in nature that alternately undermine and support Darwinian thought.
The arguments among these contemporary scholars are lively, often acrimonious, and amply fueled–after all, Darwin himself puzzled over whether natural selection was the driving force of evolutionary change. Morris offers an evenhanded account of the many schools of thought at work today, and his book will be of great interest to students of the life sciences. —Gregory McNamee