Ancient Humans Altered Andean Ecosystems Long Before Europeans Arrived, Study Finds

The scientists studied hundreds of samples of fossil pollen and charcoal from a 305-foot-long sediment core raised from Lake Junin, at an elevation of more than 13,400 feet in the grasslands of the Peruvian Andes. This sedimentary record spanned the last 670,000 years and represented the longest continuous and empirically-dated record of tropical vegetation change to date.