A TANGLED WEB

Spiders originally evolved silk to wrap and protect their eggs. While not all spiders build webs, all species do produce silk and all also wrap their eggs in the suff. The older the spider’s lineage (ie, the less it has changed over time), the more primitive its silkproducing systems. Tarantulas – including the Sydney Funnel-Web – are among the most primitive, silkwise, and can’t even really make lines. They only make sheets they use to build their nests. Other spiders have adapted silk for all kinds of elaborate systems, from huge classic-style webs strong enough to trap birds, to webs that are held in two legs and thrown over prey like a net. Even tiny jumping spiders – who don’t build webs – nevertheless use silk as drag-lines and tethers, in way that would make the most extreme parkour expert blanch.