In 2013, an ASU research team found the oldest known evidence of our own genus, Homo, at Ledi-Geraru in the lower Awash Valley of Ethiopia. A jawbone with teeth was dated to 2.8 million years ago, about 400,000 years earlier than previously known fossils of Homo. After the discovery, attention turned to reconstructing the environment of this ancient human ancestor to understand why there and why then.