The natural history of a lost sense

Abstract

This thesis is an investigation of the vomeronasal organ, which senses pheromones. It traces the use of the organ in land-dwelling vertebrates, and suggests evidence that the organ is vestigial in humans and Old World monkeys. Possible explanations for the loss of the vomeronasal organ in these groups are described and evaluated. Notably, the development of tri-color vision may have replaced pheromones for sexual selection in these lineages. This may explain the human proclivity for visual information over pheromonal cues.