EVOLUTION OF EVOLUTION OF THE EARTH, 1971 – 1994

The pioneering 1^st edition of Evolution of the Earth (McGraw-Hill, 1971) by R.H. Dott, Jr. and R.L. Batten superseded traditional historical-geology texts typically organized as a “roll call of the ages.” Rather than emphasizing “what do we know? (or think we know)” the authors took a more integrated approach, emphasizing “how do we know?” Concepts were treated in historical context, bringing a student through stages of geologic thought. In following edition, the plate-tectonics revolution and evolution-creation debates led to some significant changes.

Partly because the 1^st edition came on the cusp of plate tectonics’ integration into geology, the authors placed mobilistic concepts at the book’s end (Ch. 18), representing them as an outcome of accumulated geologic and geophysical evidence. By the 2^nd edition (1976), though, plate tectonics was presented as a unifying theory that elucidated Earth history, and thus chapters on continental drift and plate tectonics moved forward in the text, before detailed discussions of geological records of various parts of the Earth. In the 3^rd edition (1981), plate tectonics settled into its role as a comprehensive pedagogical concept; global plate reconstructions were presented in a color supplement. Eventually, chapters on continental drift, plate tectonics, and mountain-building theories were consolidated into one chapter.

With regard to evolution, Evolution of the Earth treated all aspects of the irreversible, cumulative change Earth has undergone physically, chemically and biologically. In pedagogically treating methodology, however, the authors’ emphasis on non-uniformity of rates and conditions, as well as their open discussion of the tentative nature of scientific knowledge, led some creationists to exploit selective quotes, and some scientists to criticize the book for being too tentative about evolutionary theory. Later editions addressed the evolution-creationist theory more explicitly, outlining differences between scientific and non-scientific thought. As for chapter placement, when plate tectonics moved forward, evolution moved back as far as to Ch. 10, but was moved forward to Ch. 3 in the 5^th edition (Dott & Prothero, 1994), the authors reasoning that (quoting Dobzhansky) “nothing in biology makes sense except in the light of evolution.”