A new study on stone tools from a site in India offers the latest challenge to the model of human evolution and migration that has dominated paleoanthropology, particularly in the West, for decades. The artifacts, which the researchers say were produced with a sophisticated style of tool-making, are hundreds of thousands of years older than might be expected. What does it mean? Well, that part of the story is still up for debate.

At the archaeological site of Attirampakkam in southeaste