Data from: Morph-specific artificial selection reveals a constraint on the evolution of polyphenisms

Theory predicts that the evolution of polyphenic variation is facilitated where morphs are genetically uncoupled and free to evolve towards their phenotypic optima. However, the assumption that developmentally plastic morphs can evolve independently has not been tested directly. Using morph-specific artificial selection, we investigated correlated evolution between the sexes and male morphs of the bulb mite Rhizoglyphus echinopus. Large ‘fighter’ males have a thick and sharply terminating pair of legs used to kill rival males, while small ‘scrambler’ males have unmodified legs, and search for unguarded females, avoiding fights. We selected on the relative leg width of only the fighter male morph, tracked the evolutionary responses in fighters and the correlated evolutionary responses in scramblers and females that were untouched by direct selection. Fighters diverged in relative leg thickness after six generations; assaying scramblers and females at the ninth generation we observed correlated responses in relative leg width in both. Our results represent strong evidence for the evolution of intraspecific phenotypic diversity despite correlated evolution between morphs and sexes, challenging the idea that male morphs are genetically uncoupled and free to independen- tly respond to selection. We, therefore, question the perceived necessity for genetic independence in traits with extreme phenotypic plasticity.,Data for Buzatto et al 2018 Proc BThis file has two tabs. The first one contains all the data for the selection applied on fighter males of the mite Rhizoglyphus echinopus. Each row contains information for one male measured during the experiment, and the columns contain information about (respectively from left to right): generation (1 to 10); replicate selection line; selection direction (up for thicker legs and down for thinner legs); the ID of the line (replicate and direction combined); the length of the anterior coxae suture (proxy for body size; see methods); the width of 3rd right leg (the fighting leg, measured at the base; see methods); the residual from a linear model describing the relationship between the last two variables (the allometry of the third pair of legs); whether that individual was selected as a sire for the next generation; and the number of offspring from this individual that mated and was measured in the following generation. The other tab has similar information, but only for generation 9, and including scramblers and females as well (in addition to the fighters), for investigation of the correlated evolution resulting from morph-specific selection. This tab also has the information of the family ID (since fighters, scramblers and females were sourced from a variety of different families within each line) and the sex/morph of each individual.,