Scientists had previously assumed that orb weavers diversified when flying insects did, in response to the need to specialize to catch different prey. Dimitri Dimitrov, an evolutionary biologist at the University of Copenhagen and the study’s first author, explains that his team’s research suggest “there is a no real relationship” between these two diversifications. The team’s work has shown that orb weavers diversified millions of years before flying insects.
The team used fossil records and DNA samples of existing species to create an evolutionary tree and timeline to find that orbs have a single origin.
Results also indicate that orb weavers’ diversification was in response to environmental factors, not to food shortage. Dimitrov believes that orb weavers diversified to create specialized habitats depending on their surrounding environment. Certain species specialize in webs for tall grasses, while others create webs for tall tree branches.