Archeologists are disputing the age of a jawbone found in a cave in England.

The uncertainty of science: Archeologists are disputing the age of a jawbone found in a cave in England.

Both sides of the debate agree that there is a lot riding on the outcome. “What is at stake is the entire [prehistory] of Neandertals and early modern humans in Europe,” Pettitt says. Apart from the Kents Cavern fossil and some 43,000- to 45,000-year-old teeth from Italy whose status as modern human or Neandertal is currently also debated, the oldest undisputed human fossils in Europe are about only 40,000 years old and come from a site in Romania. If modern humans really made it all the way to northwest Europe by 41,500 years ago or even earlier, it would mean that they entered Europe much earlier than once thought and also spread across the continent very rapidly. It would also increase the overlap between modern humans and the Neandertals, who already lived in Europe, and who went extinct sometime between 40,000 and 35,000 years ago. What’s more, such an overlap could make it more likely that Neandertals, who made sophisticated ornaments and tools in their last years, copied these techniques from modern humans rather than inventing them on their own.