In spite of the tremendous achievements of molecular genetics and the vast advances in the understanding of the regulation of developmental processes and the genetic control of differentiation and pattern formation, there have not been until recently many attempts to formulate a comprehensive theory of development in the context of the theory of evolution, especially by natural selection acting on heritable variation. In 1973 Dobzhansky exhorted that nothing in biology makes sense except in the light of evolution. Yet, embryology has never been integrated into the theory of evolution, some outstanding initial attempts such as E.S. Russell's Form and Function (1916) notwithstanding. Our purpose, in this note, is to draw critical attention to a recent book, The Evolution of Individuality by Leo W. Buss which provides a very important and original beginning, though perhaps only a beginning, towards that end.
Buss's book is a collection of essays, loosely integrated thematically and structurally. The central question is that of development, how the order found at various levels of organization in organisms arises. Buss proposes a simple mechanism: competitive interactions at one level of organization give rise to what appears as harmonious organization at a higher level. The argument is ingenious. Competitive interactions between entities at one level (such as cell lines) may result in conflict with the entity containing them (the individual). In such circumstances, the higher-level entity dies, taking with it its constituents. Cancer is an example of such an occurrence. However, it might be the case that synergy is established between the two levels. Then entities at both levels flourish and prosper. Thus harmony emerges from discord. Development, according to Buss is described by such a process. The lower-level entities, in this case, are the cell lineages, the upper-level is the individual.