(Phys.org)—A team of researchers from Norway, Sweden and Denmark has found evidence that suggests the nervous system evolved independently in multiple creatures over time—not just once, as has been previously thought. In their paper published in the journal Nature, the group describes their study of tiny sea creatures they collected from fjords in Norway and Sweden, from various sea floor locations, and from a site off the coast of Washington state, and what they found. Caroline Albertin and Clifton Ragsdale, with the University of Chicago, offer a News & Views piece on the work done by the team in the same journal issue.