"A few years ago, they [Neandertals] were thought to be ancestral to anatomically modern humans, but now we know that modern humans appeared at least 100,000 years ago, much before the disappearance of the Neandertals. Moreover, in caves in the Middle East, fossils of modern humans have been found dated 120,000-100,000 years ago, as well as Neandertals dated at 60,000 and 70,000 years ago, followed again by modern humans dated at 40,000 years ago. It is unclear whether the two forms repeatedly replaced one another by migration from other regions, or whether they coexisted in some areas"