Non-shocking news about ancient DNA

Tabitha M. Powledge returns to her weekly science blogs roundup with a piece about a Spanish cave that has yielded the oldest human DNA yet found — along with some thoughts about why the news media keeps treating such discoveries as a big surprise: "These discoveries seem surprising in part because many of us are still in the grip of a now-untenable idea: That human evolution (or, actually, evolution of many organisms) is lineal, a straight line of descent."