Detailed by Scientific American, a team led by biologist Raffaela Lesch collected nearly 20,000 raccoon photos from users of iNaturalist, a social network/science project that allows its users to log and share scientific observations. Lesch and the team found that across the U.S., raccoons living in cities consistently had snouts about 3.5 percent shorter than those in rural areas. That might not sound like much, but it’s significant in evolutionary terms. It’s a sign of something called “domestication syndrome,” and it isn’t a random occurrence.