The early evolution of caddisflies: Milne and Milne revisited

In 1939, Margery and Lorus Milne published a creative figure that illustrated the evolutionary history of caddisflies. Here, we pay tribute to that paper by generating a new figure in the style of the original, updated with our most recent knowledge of caddisfly evolution, informed by phylogenomic inference and a statistical treatment of ancestral states. Our analysis infers that the ancestral larval caddisfly was a free-living detritivore, living in flowing water. It spun a cocoon prior to pupation within a dome-shaped pupal shelter. In subsequent lineages, caddisflies evolved a variety of larval construction behaviors, which enabled unprecedented ecological diversification, allowing them to become one of the most diverse lineages of freshwater animals.