
PAPUA NEW GUINEA: Archaeologists have found the earliest high-altitude settlements of modern humans, 1.2 miles up in the chilly Ivane Valley. People used the five camps around 49,000 years ago, leaving behind stone tools and charred nutshells and bones. They may have lived there, as opposed to more temperate areas on the coast, to take advantage of abundant high-altitude food resources. But they would have needed some well-developed survival skills to thrive and avoid hypothermia.