Neanderthals and modern humans may not have existed together for as long as once thought, according to a study that analyzed hundreds of bones excavated from sites in modern-day Spain. The evidence suggests that there were no Neanderthals in the area after 42,000 years ago, researchers say. "Our results cast doubt on a hypothesis that has been broadly accepted since the early 1990s -- that the last place for surviving Neanderthals was in the southern Iberian Peninsula," said researcher Rachel Wood. "Much of the evidence that has supported this idea is based on a series of radiocarbon dates, which cluster at around 35,000 years ago. Our results call all of these results into question."