Ever since our ancestors cut rough paths through the wilderness, humanity has been laying down trails. From footpaths to highways, a global network of roads binds communities and facilitates the exchange of goods and ideas. But there is a flip side to this creeping tangle of pathways: The roads that bring us closer also serve divide ecosystems into smaller parcels, turning vast expanses into a jigsaw of human mobility.

In a study published last week in Science, an international team of re