Feel it in your bones

摘要

The human family tree may now be a lot cleaner, according to the discoverers of a cache of fossils on a hillside in Ethiopia. The researchers say the fossils, from the Afar region, go a long way towards showing that early hominids were not a diverse group of coexisting species. The team suggests three species evolved as a single lineage between at least 4.4 million years ago and 2.9 million years ago — an era when humankind refined its ability to walk upright while developing new ways to live (see timeline).