Phylogenetic systematics of Zygiellidae and its implications for spider evolution research

Our research on zygiellid spiders is providing novel links between the evolution of size, sexual behavior, and web morphology and thus influences the current understanding of evolutionary biology, where sexual selection may be more important for clade diversification than previously understood. We are studying the form and function of Caerostris giant webs, how they are built, what they catch, and how evolving extraordinary silk may have allowed these spiders to diversify in a novel habitat. The study is joining multiple scientific disciplines to unravel the evolutionary history of giant riverine webs, and the extraordinary silk they contain.

This work is also increasing the understanding of Malagasy biodiversity, resulting in the description of all Malagasy Caerostris species—most are new—, and providing a starting point to understand worldwide diversity and evolutionary patterns. The phylogeny is revealing the evolutionary history of these unique and giant riverine webs, and the extraordinary silk they contain, and testing the hypothesis that these striking traits coevolved. The project will provide insight to fiber science on the origin of this extraordinary silk for developing biomimetic materials. Through this study we will learn about a unique catching device and its evolution, and contribute towards the conservation of a rapidly disappearing habitat, the montane rain forests of eastern Madagascar.