Two hundred thousand years before the 21st century, there was a top predator wandering in the forests and mountains of Europe and western Asia. They looked very much like us -- they were humanlike creatures, but they were an entirely different species. The Neanderthals are an extinct type of humans that lived in Western Eurasia from 200,000 to 30,000 years ago. They had the physical strength to conquer the world, but this whole species disappeared mysteriously, leaving only tantalizing clues of their existence. Scientists now want to reconstruct this species, to see how they lived, and understand why they went extinct.