Pallab GhoshScience CorrespondentDavid BraunAt around 2.75 million years ago, the region was populated by some of the very first humans, who had relatively small brains. These early humans are thought to have lived alongside their evolutionary ancestors: a pre-human group, called australopithecines, who had larger teeth and a mix of chimpanzee and human traits.The tool users at Namorotukunan were most likely one of these groups or possibly both.And the finding challenges the notion held by many experts in human evolution that continuous tool use emerged much later, between 2.4...