Fig. 4
From: A Genetic Perspective on Eye Evolution: Gene Sharing, Convergence and Parallelism
Diagrammatic representation of two distinct molecular functions (A1 and A2) performed by differential regulation of a single gene (Gene A1/2; red) in contrast to the functional specialization of sibling genes (B1 and B2; blue) after gene duplication. The use of the single gene for two or more molecular functions is called gene sharing. Reprinted by permission from GENE SHARING AND EVOLUTION: THE DIVERSITY OF PROTEIN FUNCTIONS by Joram Piatigorsky, p. 4; Cambridge, Mass.: Harvard University Press, Copyright © 2007 by the President and Fellows of Harvard College