Digest: Evolution of dragline silk in araneids show super tensile performance in web-building and non-web-building...

Wolff (2024) takes a comparative phylogenetic approach to study the evolution of dragline silk in 164 species of spiders, including both araneid and non-araneid species. Many structural and mechanical properties of dragline silk showed no correlations; however, both tensile strength and toughness correlated with birefringence-an indicator for the directional ordering of protein materials in the silk fiber. These properties do not seem to differ between web-building and non-web-building spiders; many spider families were found to include species that produce super-performing silk as well as species that produce weak-performing silk.