1. In ancient Southwest droughts, a warning of dry times to come

    Anything but lush, the U.S. Southwest has been especially parched lately. About a decade ago a cycle of droughts began; the latest one has dried much of the region to a degree that meteorologists expect only twice a century. But look back a millennium or more, and you’ll find signs that today’s conditions are not […]

  2. Humans

    Numbers suggest mating with humans might have led to Neandertals’ demise