Researchers working in Kenya's archaeologically prolific Lake Turkana region claim to have uncovered a set of 3.3-million-year-old stone tools. That's 700,000 years older than the previous record, and predates evidence for the evolutionary origins of the genus Homo by half a million years. Above: A satellite image of Lake Turkana, where the stone tools – and many other artifacts and fossils of human ancestors – have been recovered NPR's Chris Joyce reports on the findings of Stony Brook University archaeologist Sonia Harmand and her colleagues, which were announced Tuesday at the annual meeting of the Paleoanthropology Society in San Francisco:...