Johns Hopkins University researchers discovered precisely how spiders (蜘蛛) build webs in the dark. Their creation of a web-building playbook brings new understanding of how creatures with small brains are able to create elegant and complex structures.
Web-building spiders, which build blindly using only the sense of touch, have attracted humans for centuries. "The first step to understanding that is to study the behaviors and skills involved," said Andrew Gordus, a Johns Hopkins behavioral biologist, "But until now it has never been done, mainly because of the challenge of detecting and recording the actions."
His team studied a spider native to the western United States. To observe the spiders during their nighttime web-building work, the lab designed a stage with infrared (红外线的) cameras and infrared lights. They monitored and recorded six spiders every night and tracked millions of individual leg actions. "Even if you video record it, that's a lot of legs to track,"said lead author Abel Corver. "It's just too much to go through every frame (帧) and mark the leg points by hand so we trained machine vision software to detect the actions of the spider, frame by frame, so that we could record everything the legs do to build an entire web."
They found that web-making behaviors are so similar across spiders that the researchers were able to predict the part of a web a spider was working on just from seeing the position of a leg. "Even if the final structure is a little different, the rules they use to build the web are the same," Gordus said, "which confirms the rules are in their brains."
Future work for the lab includes experiments with drugs to determine which circuits (回路) in the spider's brain are responsible for the various stages of web-building. Corver said, "This work could help us understand larger brain systems, including humans."
