Wallace on Coloration: Contemporary Perspective and Unresolved Insights.

I examine Alfred Russel Wallace's six biological categories of coloration of animals and plants, and review how they have been developed over the subsequent century and a half. These categories are: protective colors; warning colors; mimicry; sexual colors; 'typical colours'; and attractive colors in flowers and fruits. Incredibly, Wallace missed little in his appraisal of the evolutionary drivers of coloration, despite being out of step with modern sexual selection theory, and his categories still characterize much of the way that this burgeoning field is organized. Even now his encyclopedic knowledge of natural history raises intriguing functional questions about coloration that still demand investigation.