Enlarge / Look carefully into the spider's two largest eyes and you can see internal structures similar to the ones that we've evolved. (credit: Emre Can Alagöz) First, the confession: I’m an arachnophobe, spooked by the most harmless everyday spiders. Close encounters with the scarier sort—the goliath bird-eating spider in an undergraduate zoology class, the venomous redbacks sharing my tent on a research trip to Australia—well, let’s just say they taught me more about myself than about arachnids.