In this doctoral dissertation study Mark Westneat, working under the supervision of Dr. John Lundberg at Duke University, will study the evolution of feeding specializations in the cheiline wrasses, a group of fish species common in coral reef communities. Westneat has applied the concept of a four-bar- crank-chain model, borrowed from mechanical engineering, to the analysis of jaw structure and function in these fishes. Westneat has developed a computer simulation of this model which he uses to analyze data derived from high speed cinematography of wrasses feeding. A second parallel project is to reconstruct the evolutionary history of the group using modern cladistic methods. Cladistic methods are numerical procedures that examine the distributions of traits (morphological, biochemical, etc.) among the species; closely related species share more derived traits than do distantly related species. Cladistic procedures can be programmed into computers and the computers then used to reconstruct the evolutionary history of the group of species. Lundberg and Westneat will study the jaw specializations in many species of wrasses against this backdrop of evolutionary history to determine how the basic plan of the four-bar-crank-chain is modified by natural selection into many feeding specializations. This study melds modern technologies such as computer simulation, cladistic methods, high speed cinematography, etc. into a single study of the evolution of a complex system. Studies of this nature serve as paradigms for understanding the evolution of complex adaptations.