The Evolution of Pheromone Communication in the Arthropoda,

The inception of pheromone communication implies the simultaneous appearance of two new capabilities, that for biosynthesis of the pheromone and for the organization of the appropriate receptor site on a chemosensory membrane. The finding that crustecdysone, the molting hormone, is also the sex pheromone of some Brachuryan crabs suggests a solution to this problem. It has been proposed that the primordal Crustacea, having evolved the genetic capability for the synthesis of the steroid hormone and for structuring receptor sites on the target organs, through two rather minor evolutionary events involving externalization of the receptor site and release of the hormone in the urine were then capable of pheromone communication. These two events, together with sexual dimorphism under the control of the sex hormones and the associated evolution of the reproductive behavior of the male, because of their reproductive advantage, became fixed in the genome. Duplication of these two polygenic capacities provided the foundation of sex pheromone communication in the Arthropoda which through genetic mutation evolved into its sophisticated expression in modern insects. Author