The Synthesis and Evolution of a Supermodel

Threespine stickleback populations in freshwater habitats show many differences in morphology and behavior relative to their marine ancestors. A common morphological difference seen in the freshwater stickleback variants is the loss of armor plates found in marine species. In his Perspective, Gibson discusses the discovery that repeated selection of Eda alleles (encoding the protein ectodysplasin) resulted in the parallel evolution of the low-armor stickleback forms in most freshwater locations ( Colosimo et al.).