Almost everybody looking at rock art goes hunting for the pictures — the sheep, the hunters, the spirals with a story attached. (It’s the reason I drive past Mojave scratches to get to Colorado Plateau galleries.) Malotki and Dissanayake point out the oldest marks aren’t pictures at all. They’re dots, lines, grids, circles, cupules hammered into boulders, and that’s true on every continent. Malotki spent decades photographing this stuff across Arizona, Nevada, California, Idaho, and two hundred of his photographs run through the book. Dissanayake brings the theory: She calls the impulse artification, the human urge to take something ordinary and make it special, and she argues it comes before symbols and even before language has much of a role. They spend a lot of time dismantling the popular idea that shamans made these marks in trance states—watch a kid with a crayon instead, they say.