Additional file 3: File S1. of The evolution of genital complexity and mating rates in sexually size dimorphic spiders

Morphological features contributing to scores of genital complexity and their hypothesized function. Separate (Word) file. (DOCX 16 kb

Additional file 1: Table S1. of The evolution of genital complexity and mating rates in sexually size dimorphic spiders

Nephilid spider and outgroup data for all variables used in phylogenetic comparative analyses. Mating rates are inferred based on experimental and morphological evidence. Separate (Excel) file. (XLSX 16 kb

Additional file 4: Figure S2. of The evolution of genital complexity and mating rates in sexually size dimorphic spiders

Contrasting phylogenetic topologies: A, cladogram from Kuntner et al. (2008) with no branch length information; B, Bayesian tree from Kuntner et al. (2013) with rearranged taxonomic relationships and branches proportional to evolutionary change. See Methods for additional detail. Separate (pdf) file. (PDF 290 kb

Additional file 6: Figure S3. of The evolution of genital complexity and mating rates in sexually size dimorphic spiders

Relationships of studied phenotypes with female and male inferred mating rates (raw, species data). Relationships that become significant after phylogenetic correction are highlighted. (PDF 25 kb

Additional file 2: Figure S1. of The evolution of genital complexity and mating rates in sexually size dimorphic spiders

Relatively simple (left; Clitaetra) and complex (right, Herennia) genital morphology in nephilid spiders. Upper images show distal parts of the male pedipalp, lower images show female epigyna. Note that the male embolic conductor (EC) interacts with the copulatory opening (CO) of the female, and if broken off, may form an elaborate mating plug (lower right). (EPS 7104 kb

Mechanical Performance of Spider Silk Is Robust to Nutrient-Mediated Changes in Protein Composition

Spider major ampullate (MA) silk is sought after as a biomimetic because of its high strength and extensibility. While the secondary structures of MA silk proteins (spidroins) influences silk mechanics, structural variations induced by spinning processes have additional effects. Silk properties may be induced by spiders feeding on diets that vary in certain nutrients, thus providing researchers an opportunity to assess the interplay between spidroin chemistry and spinning processes on the performance of MA silk. Here, we determined the relative influence of spidroin expression and spinning processes on MA silk mechanics when <i>Nephila pilipes</i> were fed solutions with or without protein. We found that spidroin expression differed across treatments but that its influence on mechanics was minimal. Mechanical tests of supercontracted fibers and X-ray diffraction analyses revealed that increased alignment in the amorphous region and to a lesser extent in the crystalline region led to increased fiber strength and extensibility in spiders on protein rich diets