Cover Image


View/Hide Left Panel

possession of novel insights into the evolution of complexity. The claims are often spectacular. For example, Kirschner and Gerhart (2005) argue that evolutionary biology has been “woefully inadequate” with respect to understanding the origins of complexity and promise “an original solution to the long-standing puzzle of how small random genetic change can be converted into complex, useful innovations.” However, this book and many others like it (e.g., Depew and Weber, 1985; Kauffman, 1993; Carroll, 2005a; Davidson, 2006) provide few references to work done by evolutionary biologists, making it difficult to understand the perceived areas of inadequacy, and many of the ideas promoted are known to be wrong, making it difficult to appreciate the novelty. Have evolutionary biologists developed a giant blind spot; are scientists from outside of the field reinventing a lot of bad wheels; or both?

Evolutionary biology is treated unlike any science by both academics and the general public. For the average person, evolution is equivalent to natural selection, and because the concept of selection is easy to grasp, a reasonable understanding of comparative biology is often taken to be a license for evolutionary speculation. It has long been known that natural selection is just one of several mechanisms of evolutionary change, but the myth that all of evolution can be explained by adaptation continues to be perpetuated by our continued homage to Darwin’s treatise (1859b) in the popular literature. For example, Dawkins’ (1976, 1986, 1996) agenda to spread the word on the awesome power of natural selection has been quite successful, but it has come at the expense of reference to any other mechanisms, a view that is in some ways profoundly misleading. There is, of course, a substantial difference between the popular literature and the knowledge base that has grown from a century of evolutionary research, but this distinction is often missed by nonevolutionary biologists.

The goal here is to dispel a number of myths regarding the evolution of organismal complexity (Table 5.1). Given that life originated from inorganic matter, it is clear that there has been an increase in phenotypic complexity over the past 3.5 billion years, although long-term stasis has been the predominant pattern in most lineages. What is in question is whether natural selection is a necessary or sufficient force to explain the emergence of the genomic and cellular features central to the building of complex organisms.


Although the basic theoretical foundation for understanding the mechanisms of evolution, the field of population genetics, has long been in place, the central significance of this framework is still occasionally

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement