Humans, and all the species we share a planet with, evolved for total darkness at night, says The Spinoff. With our urban areas increasingly flooded with artificial light, scientists, doctors and stargazers are making a case to preserve darkness. Margaret Stanley, an associate professor of biology at the University of Auckland, studies urban ecology: the way living things are shaped by city environments. The species that humans share cities with have adapted to natural rhythms of light and darkness; but human-created light can disrupt this, creating massive flow-on effects through the ecosystem.