The vlogbrother Hank Green tells us about new and confusing discoveries in the field of Human Evolution (26 Oct 2013).
The “study, mentioned by Hank Green, and “published in the Proceedings of the National Academy of Sciences, focused on a collection of 1,200 premolars and molars from prehistoric humans. Researchers identified landmarks on the teeth and then reconstructed the tooth shape to model what they thought would be the tooth shape of humans’ common ancestor with Neanderthals. They concluded with high statistical confidence that the common ancestor does not belong to the species previously suggested, including Homo heidelbergensis, H. erectus and H. antecessora”.
But leaving the question of the common ancestor with the Neanderthals aside, ad as written by the Guardian’s science correspondent Ian Sample, the “spectacular fossilised skull of an ancient human ancestor that died nearly two million years ago has forced scientists to rethink the story of early human evolution. Anthropologists unearthed the skull at a site in Dmanisi, a small town in southern Georgia, where other remains of human ancestors, simple stone tools and long-extinct animals have been dated to 1.8m years old. Experts believe the skull is one of the most important fossil finds to date, but it has proved as controversial as it is stunning. Analysis of the skull and other remains at Dmanisi suggests that scientists have been too ready to name separate species of human ancestors in Africa. Many of those species may now have to be wiped from the textbooks. The latest fossil is the only intact skull ever found of a human ancestor that lived in the early Pleistocene, when our predecessors first walked out of Africa. The skull adds to a haul of bones recovered from Dmanisi that belong to five individuals, most likely an elderly male, two other adult males, a young female and a juvenile of unknown sex”. Tim White, an expert on human evolution at the University of California, Berkeley, stated convincingly that “Some palaeontologists see minor differences in fossils and give them labels, and that has resulted in the family tree accumulating a lot of branches. The Dmanisi fossils [now] give us a new yardstick, and when you apply that yardstick to the African fossils, a lot of that extra wood in the tree is dead wood. It’s arm-waving”.
 Zoe Mintz, “Fossil Teeth Study Says Common Ancestor Of Neanderthals And Humans Belongs To ‘Some African Species’” International Business Times (17 October 2013). http://www.ibtimes.com/fossil-teeth-study-says-common-ancestor-neanderthals-humans-belongs-some-african-species-photo.
 Ian Sample, “Skull of Homo erectus throws story of human evolution into disarray” The Guardian (17 October 2013). http://www.theguardian.com/science/2013/oct/17/skull-homo-erectus-human-evolution.
 Ian Sample, “Skull of Homo erectus throws story of human evolution into disarray”.