From - Live Science By Mindy Weisberger Edited by - Amal Udawatta Reproductions of skulls from a Neanderthal (left), Homo sapiens (middle) and Australopithecus afarensis (right) (Image credit: WHPics, Paul Campbell, and Attie Gerber via Getty Images; collage by Marilyn Perkins) Modern humans ( Homo sapiens ) are the sole surviving representatives of the human family tree , but we're the last sentence in an evolutionary story that began approximately 6 million years ago and spawned at least 18 species known collectively as hominins. There were at least nine Homo species — including H. sapiens — distributed around Africa, Europe and Asia by about 300,000 years ago, according to the Smithsonian's National Museum of Nat ural History in Washington, D.C. One by one, all except H. sapiens disappeared. Neanderthals and a Homo group known as the Denisovans lived alongside...